Medical Policy


Subject: Functional Electrical Stimulation (FES); Threshold Electrical Stimulation (TES)
Document #: DME.00022 Publish Date:    06/06/2018
Status: Reviewed Last Review Date:    05/03/2018


This document addresses uses of functional electrical stimulation (FES) and threshold electrical stimulation (TES) devices. FES is used in neurologically impaired individuals, including those with spinal cord injury and stroke, to stimulate muscles during activity. TES, also referred to as therapeutic electrical stimulation, involves the delivery of low intensity electrical stimulation (typically at night) and has been proposed as a treatment of cerebral palsy and scoliosis. 

Note: For information regarding a device that may be utilized by individuals with neurological disorders affecting the ability to ambulate without assistance, please see the following document:  

Note: FES has been used to treat or prevent muscle disuse atrophy in individuals with neurologic impairment. However, the use of electrical stimulation for the same indication in individuals without neurologic injury (typically in the postoperative setting) is addressed in the following document:

Position Statement

Investigational and Not Medically Necessary:

  1. Functional electrical stimulation (FES), when used to prevent or reverse muscular atrophy (wasting) and bone demineralization (loss), by stimulating paralyzed limbs for the performance of stationary exercise, or to correct gait disorders, is considered investigational and not medically necessary. This includes, but is not limited to, functional electrical stimulation ergometer devices (for example, ERGYS® and ERGYS® 2).
  2. Functional electrical stimulation (FES), when used to promote ambulation (for example, Parastep® I System), is considered investigational and not medically necessary.
  3. Functional electrical stimulation (FES), when used to activate muscles of the upper limb or lower limb to produce functional movement patterns is considered investigational and not medically necessary for all indications. This includes, but is not limited to, the NESS H200® Handmaster Rehabilitation System, NESS L300™ Foot Drop System, ODFS Dropped Foot Stimulator, and the WalkAide® System.
  4. Threshold electrical stimulation (TES) as a treatment of motor disorders, including, but not limited to, cerebral palsy or scoliosis, is considered investigational and not medically necessary.

FES is designed to stimulate muscles and thus improve the function of the extremities. FES has primarily been investigated in individuals with neurologic impairment, most prominently following spinal cord injury (SCI), stroke or multiple sclerosis. The stimulation is directed at improving function by utilizing devices intended to restore ambulation in the lower extremity or dexterity and function in the upper extremity; or devices to indirectly improve function, such as exercise devices adapted to FES, which are designed to prevent or treat muscle disuse atrophy. The majority of these devices use surface electrodes, but intramuscular (IM) electrodes have also been used. Standard therapy in individuals with neurologic impairment includes active and passive physiotherapy and the use of various braces and orthoses. Therefore, studies were reviewed that investigate the outcomes of FES compared to these standard therapies.

FES Devices to Prevent Muscle Atrophy and Bone Demineralization

A variety of devices use electrical muscle stimulation technology as a means of physical therapy and exercise for individuals with SCI, stroke or other neurological disorders. These devices may be referred to as functional neuromuscular exercisers or powered muscle stimulators. For treatment of the lower extremities, FES has been incorporated into an exercycle. For example, the legs are wrapped in fabric strips that contain electrodes to stimulate the muscles, thus permitting the individual to pedal. The resulting exercise is designed to prevent muscular atrophy and bone demineralization. The key outcome in the evaluation of these devices is whether the use of electrical stimulation permitting active exercise provides clinically significant incremental improvements compared to passive devices used for the same purpose.

Janssen and colleagues (2008) randomized 12 post-stroke individuals to receive cycling exercise with and without FES. Outcome measures included aerobic capacity, functional performance and lower limb strength. There was no significant difference reported between the 2 groups. A small randomized controlled trial by Ambrosini and colleagues (2011) evaluated FES cycling (FESC) (MOTOmed®, RECK GmbH, Betzenweiler, Germany) compared to passive cycling (n=35) to improve lower extremity motor functions and accelerate the recovery in post-hemiparetic individuals. Limitations of this study included the small sample size, short-term follow-up, and conflicting results. Other studies of FESC consist of small case series where the exercycle is used for a limited time as part of a rehabilitation program. No other randomized controlled studies were identified that reported the outcomes of long term use of a FESC in the home. The available peer-reviewed literature has not established the effectiveness of FESC to improve motor recovery and prevent muscle atrophy in post-stroke individuals.

In a 2-year longitudinal prospective study, Kern and colleagues (2010) attempted to confirm the results of the European Project RISE study. Muscle mass, force, and structure were determined before and after use of a home-based FES (h-bFES) using computed tomography, measurements of knee torque during stimulation, and muscle biopsy analysis in individuals (n=25) with complete conus and cauda equina spinal cord lesions. A total of 5 of the original 25 participants dropped out from the final study results. A cross-sectional increase in area of the quadriceps muscle from 28.2 ± 8.1 to 38.1 ± 12.7 cm2 (p<0.001), a 75% increase in the mean diameter of muscle fibers from 16.6 ± 14.3 to 29.1 ± 23.3 µm (p<0.001), and an increase in force output during electrical stimulation (p<0.001) was reported. However, limited “measurable” knee torque changes in h-bFES trained muscles were evident. Complete lower extremity denervation remained before initiation, during and after the 2 years of training with the h-bFES.

Johnston and colleagues (2011) attempted to determine the effect of cycling, electrical stimulation, or both, on thigh muscle volume and stimulated muscle strength in a small comparative, controlled trial of 30 children with SCI. Participants were randomly assigned to one of three interventions: FESC, passive cycling (PC), and noncycling, electrically stimulated exercise (ES). Each group exercised for 1 hour, 3 times per week for 6 months at home. Pre- and post-intervention, children underwent magnetic resonance imaging (MRI) to assess muscle volume, and electrically stimulated isometric muscle strength testing with the use of a computerized dynamometer. All 30 children completed the training. Muscle volume data were complete for 24 children (8 FESC; 8 PC; 8 ES) and stimulated strength data for 27 children (9 per group). Per analyses of covariance, there were differences between groups (p<0.05) for quadriceps muscle volume and stimulated strength, with the ES group having greater changes in volume and the FESC group having greater changes in strength. Although quadriceps strengthening for the ES group increased (p=0.024), a corrected value (p=0.0167) was needed to reach statistical significance. The authors stated a larger sample size would have increased the power, which suggests this finding may be significant. However, it is unknown how the changes in the muscle volume and strength may lead to a change in clinically significant and meaningful improvement in the health status of these children. Other study limitations include missing data (that is, poor quality MRIs, failure to return for follow-up strength testing), and lack of consideration to the stage of maturation of the participants. Further long-term studies are required to evaluate if FESC can improve health outcomes for children with SCI.

Lauer and colleagues (2011) conducted a small study to determine the effect of cycling and/or electrical stimulation on hip and knee bone mineral density (BMD) in children with SCI, randomized to one of three interventions: FESC, PC, and non-cycling ES. Each group exercised for 1 hour, 3 times per week for 6 months at home. The hip, distal femur and proximal tibia BMD were examined via dual-energy X-ray absorptiometry (DXA) pre- and post-intervention. The FESC group exhibited increases in hip, distal femur and proximal tibia BMD of 32.4%, 6.62% and 10.3%, respectively; however, there were no differences between groups or within groups over time. Further study is needed with a larger sample size to determine the net health benefit of FESC for children with SCI.

Craven and colleagues evaluated the efficacy of FES therapy (FES-T) assisted walking compared to a conventional aerobic and resistance training program (CONV) to improve bone turnover and bone strength in individuals with chronic motor incomplete SCI. Adult participants (n=34) with C2-T12 American Spinal Injury Association (ASIA) Impairment Scale C-D were randomized to FES-T (n=17) or CONV training (n=17) for 45 minutes 3 times weekly for 4 months. Osteocalcin (OC), β-cross laps (CTX) and sclerostin were assessed at baseline, and 4 months in addition to total hip, distal femur and proximal tibia region BMD and tibia bone quality were assessed at baseline, 4, and 12 months. A total of 27 participants completed the 4-month intervention and 12-month outcome assessments. Participants in the FES-T arm had a decrease in CTX and a significant increase in OC at intervention completion (p<0.05) with no significant biomarker changes observed in the CONV group. No within or between group differences from baseline were observed in sclerostin or bone strength.

In a systematic review of evidence-based prevention and treatment of osteoporosis after SCI, Soleyman-Jahi and colleagues (2017) reported that very low-quality evidence did not show any benefit for low-intensity (3 days per week) FES cycling in chronic SCI. The authors recommended high-quality randomized controlled studies with larger homogeneous sample sizes are needed to make strong recommendations for prevention and treatment of SCI-related bone loss.

FESC with devices such as the ERGYS (K841112) (Therapeutic Alliances Inc., Fairborn, Ohio) and RT300-S/RT300-SP (K050036) (Restorative Therapies, Inc., Baltimore, MD) have received U.S. Food and Drug Administration (FDA) 510(k) clearance as in-home physical therapy and exercise equipment, indicated for general rehabilitation for: 1) relaxation of muscle spasms; 2) prevention or retardation of disuse atrophy; 3) increasing local blood circulation; and, 4) maintaining or increasing range of motion. In addition, FES cycle training has been proposed as a means to reduce cardiorespiratory and musculoskeletal stress to minimize the health risks associated with inactivity and lower extremity paralysis after SCI. The peer-reviewed published literature consists of review articles (Martin, 2012), small case series and non-randomized and randomized controlled studies investigating cardiorespiratory responses and training effects of FESC “to improve cardiorespiratory fitness” in individuals with SCI. Faghri and colleagues (1992) evaluated cardiorespiratory responses at rest and during submaximal FES-induced leg cycle ergometer exercise prior to and following a progressive intensity FES-exercise training program in 7 individuals with quadriplegia and 6 individuals with paraplegia. After 3 sessions per week for approximately 12 weeks (36 sessions), the investigators reported respiratory responses were not significantly altered by training in both groups (p>0.05). Participants with quadriplegia demonstrated significantly lower resting blood pressure and heart rates (pre- and post-training) compared to participants with paraplegia; although, the observed changes following the short-term program may not be clinically significant. In a small case series (n=11) of individuals with paraplegia, Berry and colleagues reported that oxygen cost and efficiency did not significantly change after a 12-month, home-based, progressive FES cycle training program. Johnston and colleagues (2009) examined the cardiorespiratory/vascular effects of cycling with and without FES in children ages 5 to 13 years with SCI (n=30) with injury levels from C4 to T11. Children were randomly assigned to 1 of 3 groups: FESC, passive leg cycling, or a non-cycling control group receiving electrical stimulation therapy. The children exercised at home for 1 hour 3 times per week for 6 months with parental supervision. The investigators reported no difference between groups (p>0.05) after 6 months of exercise when comparing pre- and post-therapy values for oxygen update, resting heart rate, forced vital capacity, and a fasting lipid panel. Although no significant safety issues have been identified with use of FES ergometer cycling, to date, the FDA’s summary of safety and effectiveness for FES cycle ergometers do not indicate the devices have been cleared for use to prevent secondary dysfunction such as alterations in cardiovascular function, or to promote cardiovascular conditioning, associated with damage to motor nerve pathways in individuals with SCI and other neurological disorders affecting the lower extremities.

FES Devices to Restore Ambulation

Parastep I System

The clinical impact of the FES devices to provide ambulation rests on identification of clinically important outcomes. For example, the primary outcome of the Parastep I System device (Sidmedics, Inc., Fairborn, Ohio), and the main purpose of its design, is to provide a degree of ambulation that improves the individual’s ability to complete the activities of daily living, seek employment, or positively affect the individual’s quality of life. Physiologic outcomes (for example, conditioning, oxygen uptake) have also been reported, but these are intermediate, short-term outcomes, and it is not known whether similar or improved results could be attained with other training methods. In addition, the results are reported for mean peak values, which may or may not be a consistent result over time. The effect of the Parastep on physical self-concept and depression are secondary outcomes and similar to the physiologic outcomes; interpretation is limited due to lack of comparison with other forms of training.

The largest study of the Parastep device was conducted by Chaplin and colleagues (1996) who reported on the ambulation outcomes using the device in 91 individuals. A total of 84 of the 91 individuals (92%) were able to take steps and of these, 31 of the 91 individuals (34%) were able to eventually ambulate without assistance from another person. Duration of use was not reported. Other studies of the Parastep device include a series of five studies from the same group of investigators, which focused on different outcomes in the same group of 13 to 15 individuals. Jacobs and colleagues (1997) reported on physiologic responses related to use of the Parastep device. There was a 25% increase in time to fatigue and a 15% increase in peak values of oxygen uptake, consistent with an exercise training effect. There were no significant effects on arm strength. Needham-Shropshire and colleagues (1997) reported no relationship between use of the Parastep device and BMD, although the time interval between measurements (12 weeks) and the precision of the testing device may have limited the ability to detect a difference. Nash and colleagues (1997) reported that use of the Parastep device was associated with an increase in arterial inflow volume to the common femoral artery, perhaps related to the overall conditioning response to the Parastep. Finally, Guest and colleagues (1997) reported on the ambulation performance of 13 men and 3 women with thoracic motor complete spinal injury. All individuals underwent 32 training sessions prior to measuring ambulation. The group’s mean peak distance walked was 334 meters, but there was wide variability, as evidenced by a standard deviation of 402 meters. The mean peak duration of walking was 56 minutes, again with wide variability, evidenced by a standard deviation of 46 minutes. It should be noted that peak measures reflect the best outcome over the period evaluated; peak measures may be an inconsistent, one-time occurrence for the specific individual. The participants also underwent anthropomorphic measurements of various anatomic locations. Increases in thigh and calf girth, thigh cross-sectional area, and calculated lean tissue were all statistically significant. The authors emphasize that the device is not intended to be an alternative to a wheelchair, and thus other factors such as improved physical and mental well-being should be considered when deciding whether or not to use the system. The same limitations were noted in a review article by Graupe and Kohn (1998), who state that the goal for ambulation is for individuals to get out of the wheelchair at will, stretch, and take a few steps every day.

It should be noted that evaluations of the Parastep device were performed immediately following initial training or during limited study period durations. There is limited data regarding whether individuals remain compliant and committed with long-term use. Brissot and colleagues (2000) reported independent ambulation was achieved in 13 of 15 individuals, with 2 individuals withdrawing from the study. In the home setting, 5 of the 13 individuals continued using the device for physical fitness, but none used it for ambulation.

In summary, studies of the Parastep FES device used for ambulation demonstrate the device is associated with improvements in the intermediate outcomes of a variety of physiologic outcomes. However, there is inadequate data to show that these benefits exceed those offered by non-functional (passive) stimulation approaches. While device users can stand and walk short distances, there is inadequate data to show whether this results in clinically significant improvements in activities of daily living, and inadequate results to demonstrate that individuals consistently use the device over the long term. In addition, FES can expose the subject to significant risks such as falls, sprains and bone fractures.

Other FES Devices to Restore Ambulation

Reciprocating gait orthoses consist of a rather cumbersome hip-knee-ankle-foot device linked together with a cable at the hip joint. These orthoses have been used in conjunction with FES as a hybrid device to reduce the energy requirement of walking. The literature includes a number of studies; 1 compared use of the orthosis with and without FES (Sykes, 1996). The study included only 5 subjects and concluded that there was no significant difference in energy requirement between the two devices. Solomonow and colleagues (1997) published two case series of 70 individuals which studied ambulation performance (Part I) and physiological outcomes (Part II). Of the 70 individuals who completed an initial 14-week training period, 41 continued to use the orthosis at home on a long term basis. A total of 80% of these reported that they were regular users of the device. The authors concluded that the device could restore standing and limited walking in carefully selected paraplegics. This study has not been followed by any additional studies, and it appears that reciprocating gait orthoses have not been widely accepted.

FES has also been investigated using IM electrodes. For example, Johnston and colleagues (2003) investigated IM electrodes placed to stimulate hip and knee extension, and hip abduction and adduction, which were used in conjunction with various orthoses. The technique was investigated in 7 children with SCI. The individuals reported improvements in time to complete tasks and level of independence. The authors concluded that the use of IM electrodes was feasible. Other reports of this technique similarly consist of small case series.

Daly and colleagues (2011) tested a multimodal gait training protocol, with or without FES, to improve volitional walking (without FES) in individuals with persistent (> 6 months) dyscoordinated gait following stroke. A total of 53 subjects were stratified and randomly allocated to either FES with IM electrodes (FES-IM) or No-FES. Both groups received 1.5-hour training sessions 4 times a week for 12 weeks of coordination exercises, body weight-supported treadmill training (BWSTT), and over-ground walking, provided with FES-IM or No-FES. The primary outcome was the Gait Assessment and Intervention Tool (G.A.I.T.) of coordinated movement components. The G.A.I.T. showed an additive advantage with FES-IM versus No-FES (parameter statistic 1.10; p=0.045; 95% confidence interval [CI], 0.023-2.179) at the end of training. For both FES-IM and No-FES, a within-group, pre-and post-treatment gain was present for all measures (p<0.05), and a continued benefit from mid- to post-treatment (p<0.05) was present. For FES-IM, recovered coordinated gait persisted at 6-month follow-up but not for No-FES. A total of 44 subjects completed the study (17% dropout rate); however, the authors noted that these participants did not significantly differ in pre-treatment characteristics from the 53 who started the study. A limitation of the findings is that FES-IM is an invasive procedure that uses a research stimulation system, which is not yet clinically available. The system used in the study was an 8-channel system that was portable and programmable, and easy to don. Implementing the FES-IM in clinical practice would involve an outpatient surgical procedure and the FES technology. In addition, data reporting long term outcomes as measured by sustained and continued improvement beyond the treatment duration of 12 weeks are necessary to determine the net benefit of FES-IM for individuals with moderate to severe impairment in gait coordination due to stroke.

Giangregorio and colleagues (2012) evaluated the effects of FES-assisted walking on body composition, compared to a non-FES exercise program in individuals with a SCI. In this parallel-group study, 34 participants with chronic (≥ 18 months) incomplete SCI (level C2 to T12, ASIA Impairment Scale C or D) were recruited and randomized to FES-assisted walking (intervention), or aerobic and resistance training (control) sessions 3 times a week for 16 weeks. Whole body and leg lean mass and whole body fat mass (measured with dual-energy X-ray absorptiometry) and lower-limb muscle cross-sectional area (CSA) and fat CSA (measured with peripheral computed tomography) were assessed at baseline, 4 months, and 12 months. Intention-to-treat (ITT) analyses using repeated measures general linear models were used to assess between-group differences. At 12 months, 27 participants (79%) remained in the study. There were no significant main effects of FES-assisted walking on body composition variables in ITT analyses with group means. There were 13 side effects or adverse events related to study participation; most were resolved with modifications to the protocol. The study results did not demonstrate that 3 times a week FES-assisted walking exercise over 4 months resulted in a change in body composition in individuals with chronic, motor incomplete C2 to T12 SCI. However, follow-up at 12 months revealed a significant between-group difference in maintaining muscle area in favor of FES. Conclusions drawn from this study are limited by the large variability across participants and a high loss-to-follow-up rate, particularly in the control group. Additional large, well-designed trials are needed to verify if muscle area decreases over time in individuals with chronic SCI and if FES can prevent or reverse these changes.

Kafri and Laufer (2015) systematically reviewed the literature to assess the carryover effects of lower extremity FES motor performance following stroke. A total of 16 randomized and non-randomized trials met the inclusion criteria. The therapeutic effects of FES were measured at > 3-6 months in the chronic post-stroke phase. In 11 studies, the overall findings indicated “clinically important” increases in speed. The positive therapeutic effects of FES were reported for other mobility-related variables including walking independence (two studies), walking distance (three studies), stair negotiation (two studies), and muscle strength and voluntary range of motion (nine studies). The therapeutic effect of FES on balance did not demonstrate any clear patterns of response (five studies). The effects of FES on spasticity indicated a positive effect in the sub-acute (one study) and chronic phases (three studies) of stroke; however, the investigators questioned whether the therapeutic effects specific to the FES intervention “…are due primarily to the electrical stimulation delivered by the FES…or whether they can be achieved by any means that enable functional movement.” Contradictory findings were identified in the training studies regarding the superiority of FES with training relative to control training without FES. No superior effects were reported when FES was used as an alternative to ankle-foot orthosis (AFO) (four studies). Although some positive effects of FES training were reported, the results were inconsistent when FES was compared to matched treatments that did not incorporate FES. The investigators concluded it was “difficult to determine optimal treatment protocols due to inconsistent and wide ranging outcome measures, varying exposures to FES, and the different FES parameters used.” Additional well-designed, controlled studies are required to substantiate the therapeutic effects of FES to promote gait performance and lower extremity motor recovery following stoke.

Khamis and colleagues (2018) conducted a systematic review examining the evidence for use of surface FES to any lower leg muscles to improve gait deviations, functional ability, and therapeutic effects in children with cerebral palsy. A total of 15 studies (n=151 children), including one randomized controlled trial, two non-randomized controlled trials, five single-subject designs, one cross-over design, three case series, two case studies, and one exploratory design study were included in the analysis. Six studies included a control group, with five matched control studies and three healthy control groups. The most common FES device stimulated the dorsiflexors muscles with a positive orthotic effect, improved dorsiflexion during the swing phase and enhanced the foot contact pattern. A small positive effect was found for knee extensors stimulation facilitating knee extension during the stance phase and for hip abductors stimulation improving frontal plane knee alignment. There was no evidence to support the use of plantar flexors stimulation in correcting gait deviations and scarce evidence of any retention effect. The investigators concluded that FES should be evaluated in randomized studies with larger populations to determine the orthotic and therapeutic effect of FES to improve gait in individuals with cerebral palsy.

Moll and colleagues (2017) performed a systematic review of 14 publications to assess the effect of FES on ankle dorsiflexors during walking in children and adolescents with spastic cerebral palsy. Only five articles (three studies) were of level I to III evidence. Outcomes were classified according to the International Classification of Functioning, Disability and Health (ICF). At ICF participation and activity level, there was limited evidence for a decrease in self-reported frequency of toe-drag and falls. At ICF body structure and function level, there was evidence (I-III) that FES increased (active) ankle dorsiflexion angle, strength, and improved selective motor control, balance, and gait kinematics, but decreased walking speed. The authors concluded there was insufficient data supporting functional gain by FES on activity and participation level; however, there may be a potential role for FES as an alternative to orthoses in children with spastic cerebral palsy.

Other Uses of FES Devices

Elbow, Hand, and Shoulder

FES of the shoulder has been incorporated into post-rehabilitation primarily as a technique to reduce shoulder pain that is commonly associated with hemi- or paraplegia secondary to stroke or SCI. The effectiveness of FES has also been investigated with bilateral activities training on upper limb function in individuals with chronic stroke. Similar to the shoulder, key outcomes focus on a comparison of function of those treated with physiotherapy with and without FES. In a double-blind randomized controlled trial, Chan and colleagues (2009) evaluated 20 individuals, 6 months after the onset of stroke to receive 15 training sessions of stretching activities, FES with bilateral tasks, and occupational therapy treatment. The outcome measures included Functional Test for the Hemiplegic Upper Extremity (FTHUE), Fugl-Meyer Assessment (FMA), grip power, forward reaching distance, active range of motion of wrist extension, Functional Independence Measure, and Modified Ashworth Scale. At baseline comparison, there was no significant difference in both groups. After 15 training sessions, the FES group had significant improvement in FMA (p=0.039), FTHUE (p=0.001), and active range of motion of wrist extension (p=0.020) when compared with the control group. The authors concluded that bilateral upper limb training with FES could be an effective method for upper limb rehabilitation of post-stroke individuals after 15 training sessions. This trial is limited in its application by the small sample size, short duration of treatment, and lack of long-term outcome measures.

Ring and Rosenthal (2005) reported on a case series of 22 individuals with moderate to severe limb paresis 3 to 6 months following stroke. Participants were categorized into those with or without active finger movements and then randomized to receive either FES (Handmaster; now known as the NESS H200 Hand Rehabilitation System, Bioness, Inc, Valencia, CA) or standard physiotherapy. The FES group had greater improvements in spasticity, active range of motion and functional hand scores. Interpretation of this study is limited by its small size. The largest study identified consisted of a historical cohort study of 110 individuals with chronic stroke (Meijer, 2009). Participants were evaluated before and after a 6-week “try-out” period of the Handmaster device, and then again after a 4-week “withhold” period to determine the durability of any initial response. A prescription for long-term use was based on positive responses (primarily a reduction in hypertonia) during the initial trial period followed by relapse in the “withhold” period. Individuals prescribed a device for long-term use were sent a questionnaire investigating the actual use of the device. Users were defined as those using the device for at least 15 minutes on a daily basis. Everyone else was categorized as a non-user. Of the 147 potential participants, 110 met the criteria and agreed to participate; 86 (76%) were categorized as users. Given the high percentage of continued use, the authors concluded that the initial short-term benefit used as participant selection criterion predicted long-term use. Interpretation of this study is limited by the retrospective study design, including the lack of a control group or comparison to standard physical therapy.

Koyuncu and colleagues (2010) conducted a randomized controlled trial to evaluate FES for the treatment of shoulder subluxation and pain in individuals with hemiplegia. All 50 participants received conventional rehabilitation methods and the study group was additionally applied FES to the supraspinatus and posterior deltoid muscles (hemiparetic side) for 1 hour, 5 times a day, for 4 weeks. The shoulder pain of all participants during resting, passive range of motion (PROM) and active range of motion (AROM) was measured with the visual analog scale (VAS). Shoulder subluxation levels were compared before and after physical therapy and the rehabilitation program using millimetric measurements on anteroposterior shoulder X-rays. Comparison of the resting AROM to the PROM VAS showed no significant difference between the groups. There was a significant difference between the 2 groups for the amount of change in shoulder subluxation and subluxation levels (p<0.001; p<0.05, respectively) in the study group but not in the control group. The small sample population and short-term follow-up are limitations of this study.

Harvey and colleagues (2016) performed a multicenter, parallel group, randomized controlled trial to evaluate the effect of adding an intensive task-specific hand-training program involving FES to a combination of usual care plus three 15-minute sessions per week of one-to-one hand therapy in 70 individuals with C2 to T1 motor complete or incomplete tetraplegia within 6 months of injury. Control participants received usual care consisting of functional hand activities and did not receive the intensive task-specific hand-training program with FES. The primary outcome was the modified Action Research Arm Test (m-ARAT) of the target hand (reflecting arm and hand function), which was assessed 11 weeks after randomization. Secondary outcomes were measured at 11 and 26 weeks. A total of 66 (94%) participants completed the post-intervention assessment and were included in the primary ITT analysis. The m-ARAT score for experimental and control participants at the post-intervention assessment was 36.5 points (standard deviation [SD] 16.0) and 33.2 points (SD 17.5), respectively, with an adjusted mean between-group difference of 0.9 points (95% CI, -4.1 to 5.9). The investigators concluded that adding an intensive task-specific hand-training program involving FES to a combination of usual care plus three 15-minute sessions per week of one-to-one hand therapy did not improve hand function in people with sub-acute tetraplegia.

Gus and Ran (2016) performed a systematic review and meta-analysis of 15 randomized controlled trials to evaluate the effect of FES given in combination with conventional therapy for shoulder subluxation, pain, upper arm motor function, daily function, and quality of life in individuals post-stroke. On meta-analysis, a significant difference was found in shoulder subluxation between the FES group and the placebo group, but only if FES was applied early after stroke; however, FES therapy did not reduce shoulder pain or improve upper arm motor function, daily function, and quality of life at any other time after stroke. Another meta-analysis reported similar results with FES therapy, in that a significant difference in shoulder subluxation was reported if FES was applied early after stroke, but there were no effects on pain reduction or improved upper arm motor function any time after stroke (Vafadar, 2015).

Eraifej and colleagues (2017) conducted a systematic review and meta-analysis of 20 studies to evaluate the effect of upper limb FES given in combination with standard care for improvement of activities of daily living and motor function in post-stroke rehabilitation. No significant benefit of FES was found for objective activities of daily living measures in six studies (standardized mean difference [SMD] 0.64; 95% CI, -0.02 to 1.30); n=67 FES participants). Only three studies showed a significant benefit of FES on activities of daily living when initiated within 2 months post-stroke (SMD 1.24; CI, 0.46 to 2.03; n=32 FES participants). In three studies where FES was initiated more than 1 year after stroke, no significant activities of daily living improvements were seen (SMD -0.10; CI, -0.59 to 0.38; n=35 FES participants). Limitations of the evaluable studies included “very low quality evidence in all analyses due to heterogeneity, low participant numbers and lack of blinding.”

Other studies utilizing FES devices for upper extremity conditions consist of small case series; no study had more than 20 participants (Alon, 2003; Hendricks, 2001; Santos, 2006; Snoek, 2000; Sullivan, 2007; Weingarden, 1998).

Lower Extremity

Foot drop is weakness of the foot and ankle that causes reduced dorsiflexion and difficulty with ambulation. It can have various causes such as stroke or nerve injury. Treatment typically consists of an ankle foot orthosis or another type of limb brace. These devices are designed to provide stability. In contrast, FES devices are designed to improve function by enabling the foot to be raised during the swing phase of ambulation.  

Post-Stroke Hemiparesis or Traumatic Brain Injury  

Ring and colleagues (2009) compared the effects of a radiofrequency-controlled neuroprosthesis on gait stability and symmetry to the effects obtained with a standard AFO in a small comparative study of 15 individuals with prior chronic hemiparesis resulting from stroke or traumatic brain injury whose walking was impaired by foot drop and who regularly used an AFO. After a 4-week adaptation period, there were no differences between walking with the neuroprosthesis and walking with the AFO (p>0.05). After 8 weeks, there was no significant difference in gait speed, whereas stride time improved from 1.48 seconds (± 0.21 seconds) with the AFO to 1.41 seconds (± 0.16 seconds) with the neuroprosthesis (p<0.02). Swing time variability decreased from 5.3% (± 1.6%) with the AFO to 4.3% (± 4%) with the neuroprosthesis (p=0.01). A gait asymmetry index improved by 15%, from 0.20 (± 0.09) with the AFO to 0.17 (± 0.08) with the neuroprosthesis (p<0.05). The authors concluded that compared with AFO, the studied neuroprosthesis appears to enhance balance control during walking and, thus, more effectively managed foot drop. Additional study is required involving larger sample populations that measure long-term outcomes.

Hausdorff and Ring (2008) studied 24 individuals with hemiparesis whose ambulation was impaired due to foot drop. Subjects walked for 6 minutes with and without an FES device using surface electrodes. Additional assessments while using the FES device were conducted at 4 and 8 weeks. A gait asymmetry index significantly improved at initial evaluation with the 6-minute walk test and after 8 weeks. Walking speed and stride time also significantly improved at the two time periods. Limitations of this study include the small number of participants and short-term follow-up.  

Kottink and colleagues (2007) reported on a trial of 29 individuals with stroke who were randomized to receive either an implantable peroneal nerve stimulator or usual care group consisting of either an orthosis or no specific therapy. The primary outcome measure was walking speed assessed by a 6-minute walk test, which improved by 23% in the FES group. Interpretation of this study is limited by its small size. The second study included 32 post-stroke individuals who were randomized to FES or a control group receiving physiotherapy (Daly, 2006). There was no significant difference in walking distance between the 2 groups.

Taylor and colleagues (1999) retrospectively evaluated 151 individuals who had used the OdStock Dropped Foot Stimulator (ODFS) device (Odstock Medical Limited, Salisbury, Wiltshire, UK; NDI Medical, Cleveland, OH) for a minimum of 4.5 months. There was a 12% increase in walking speed and a decrease in effort by 12%. Pomeroy and colleagues (2006) completed a systematic review and meta-analysis of electrical stimulation in the post-stroke setting. The review included randomized controlled trials of electrostimulation delivered to the peripheral neuromuscular system which was designed to improve voluntary movement control, functional motor ability and activities of daily living. A total of 24 trials were reviewed. The authors concluded that:

At present, there are insufficient robust data to inform clinical use of electrostimulation for neuromuscular re-training. Research is needed to address specific questions about the type of electrostimulation that might be most effective, in what dose and at what time after stroke.

Embrey and colleagues (2010) attempted to evaluate whether FES timed to activate the dorsiflexors and plantar flexors during gait improved the walking of adults with hemiplegia in a small randomized crossover trial conducted in an outpatient rehabilitation clinic setting. A total of 28 adults with hemiplegia completed 3 months of intervention “A” (wearing the FES system for a specified time during walking) or “B” (walking without the FES system). Crossover occurred at 3 months, with the A-B group continuing to walk but without receiving FES. Outcomes were measured without electrical stimulation at pretreatment, 3 months, and 6 months. In phase 1, participants who received treatment A (A-B group) showed improvement compared with participants who received treatment B (B-A group) on a 6-minute walk test (p=0.02), Emory Functional Ambulatory Profile (p=0.08), and Stroke Impact Scale (p=0.03). In phase 2, the A-B group maintained improvement in all three primary outcomes even without FES; however, the carryover improvements were not statistically different from their performance at crossover. Both groups improved significantly on all primary outcome measures when initial measurements were compared to measurements at 6 months (p≤0.05). This study however, is limited in drawing conclusions due to the small number of participants, crossover at 3 months, and short-term follow-up.

Pereira and colleagues (2012) conducted a systematic review on the effectiveness of FES in improving lower extremity function in chronic stroke. Studies included in the review were 1) randomized controlled trials; 2) ≥ 50% of the study population had sustained a stroke; 3) the mean time since stroke was ≥ 6 months; 4) FES or neuromuscular electrical stimulation (NMES) was compared to other interventions or a control group; and 5) functional lower extremity outcomes were assessed. A total of seven randomized controlled trials including a pooled sample size of 231 participants met inclusion criteria. Pooled analysis revealed a small but significant treatment effect of FES (0.379 ± 0.152; 95% CI, 0.081 to 0.677; p=0.013) on a 6-minute walk test. The authors concluded that FES may be an effective intervention in the chronic phase post stroke, however, “its therapeutic value in improving lower extremity function and superiority over other gait training approaches remains unclear.”

Kluding and colleagues (2013) conducted a multicenter, randomized, single-blinded industry-sponsored trial comparing the NESS L300 Foot Drop System to an AFO for drop foot among individuals at least 3 months after stroke with gait speed ≤ 0.8 meters/second (m/s). A total of 197 participants (61.14 ± 11.61 years of age; time after stroke 4.55 ± 4.72 years) were randomized to 30 weeks of either NESS L300 or a standard AFO. A total of 8 dose-matched physical therapy sessions were provided to both groups during the first 6 weeks of the trial. There was significant improvement reported within both groups from baseline to 30 weeks in comfortable gait speed (95% CI for mean change, 0.11-0.17 m/s for NESS L300 and 0.12-0.18 m/s for AFO), fast gait speed, and the secondary outcome of user satisfaction with the NESS L300 device; however, the authors noted that “…poor compliance with AFOs has been reported in people with foot drop and may have been a factor leading to the lack of adequate use of AFOs in many of the participants at enrollment into the study.” Despite improvements reported in gait speed and user satisfaction with the NESS L300 device within both groups, the study did not demonstrate greater improvement in gait speed in participants randomized to the NESS L300 group, as no significant differences in gait speed were found in the between-group comparison analysis. O’Dell and colleagues (2014) performed a secondary analysis of data from this study. Comfortable gait speed was assessed in 99 individuals from the NESS L300 group at 6, 12, 30, 36, and 42 weeks, with and without use of the foot drop stimulator. A responder was defined as achieving a minimal clinically important difference of 0.1 m/s on the 10MWT or advancing by at least 1 Perry Ambulation Category. Noncompleters were classified as nonresponders. A total of 70% of participants completed the assessments at 42 weeks and 67% of participants were classified as responders. Of the 32 participants who were classified as nonresponders, 2 were nonresponders and 30 were noncompleters. The study did not report the percentage of participants in the conventional AFO group who were classified as responders at 30 weeks. A total of 160 adverse events were reported, 92% were classified as mild, with 50% and 27% attributed to reversible skin issues and to falls, respectively.

Sheffler and colleagues (2013) conducted a single-blinded randomized controlled trial comparing the motor relearning effect of the ODFS device versus usual care on lower limb motor impairment, activity limitation, and quality of life among 110 chronic post-stroke (> 12 weeks) survivors. After stratification by motor impairment level, participants were randomly assigned to ambulation training with either the ODFS device or usual care (AFO or no device) intervention and treated for 12 weeks with follow-up for 6 months post-treatment. Primary outcome measures included lower limb portion of the FMA (motor impairment), the modified Emory Functional Ambulation Profile (mEFAP) performed without a device (functional ambulation), and the Stroke Specific Quality of Life (SSQOL) scale. The investigators reported that the use of the ODFS device and usual care were not associated with improvements in motor relearning among chronic stroke survivors as measured by lower extremity FMA; in addition, there was no significant treatment group main effect or treatment group by time interaction effect on mEFAP or SSQOL raw scores (p>0.05). A secondary finding of this trial was that the ODFS device was no more effective than usual care on functional mobility (that is, activity limitation). This study was limited by an inability to reach the target recruitment which resulted in the lack of power to detect a smaller treatment effect, a large dropout rate (24%), and short duration of treatment with the ODFS device (12 weeks).

Prenton and colleagues (2016) performed a meta-analysis of seven randomized controlled trials comparing the effects of unassisted walking behaviors with assisted walking following use of FES and AFO for foot drop of central neurological origin. Two of the trials reported different results from the same trial and another two trials reported results from different follow-up periods and were therefore combined, resulting in five “synthesized trials” with 815 stroke participants. Meta-analyses of data from the final assessment in each study and three overlapping time-points showed comparable improvements in walking speed over 10 meters (p=0.04-0.79), functional exercise capacity (p=0.10-0.31), timed up-and-go (p=0.812 and p=0.539) and perceived mobility (p= 0.80) for both interventions. The data suggested that an AFO has equally positive combined-orthotic effects as FES on key walking measures for foot drop caused by stroke. The investigators recommended that additional long-term, high-quality randomized controlled trials are required, focusing on “measuring the mechanisms-of-action, whether there is translation of improvements in impairment to function, plus detailed reporting of the devices used across diagnoses. Only then can robust clinical recommendations be made.”

Additional small nonrandomized studies, and randomized controlled and comparative trials, have evaluated the use of FES to reduce ankle spasticity or improve muscle strength, walking ability (that is, gait performance) and metabolic responses in the management of drop foot in individuals with post-stroke hemiparesis (Cheng 2010; Sabut, 2010a; Sabut, 2010b; Springer, 2012; Springer, 2013). Limitations of these studies include, but are not limited to, small participant populations, lack of blinding to treatment, and short-term follow-up.

Multiple Sclerosis-associated Foot Drop

Barrett and colleagues (2009) investigated the effects of FES and therapeutic exercise on walking performance in a 2-group randomized trial (n=44) assessing the effects of single channel common peroneal nerve stimulation on objective aspects of gait relative to exercise therapy for persons with secondary progressive multiple sclerosis (SPMS) and unilateral foot drop. A total of 20 individuals were randomly allocated to a group receiving FES and the remaining 24 to a group receiving a physiotherapy home exercise program for a period of 18 weeks. The exercise group showed a statistically significant increase in walking speed and distance walked in 3 minutes, relative to the FES group who showed no significant change in walking performance without stimulation. At each stage of the trial, the FES group performed to a significantly higher level with FES than without for the same outcome measures. The investigators concluded that exercise may provide a greater training effect on walking speed and endurance than FES for persons with SPMS. FES may provide an orthotic benefit when outcome is measured using the same parameters. However, more research is required to investigate the combined therapeutic effects of FES and exercise for this particular group of individuals.

A small randomized controlled trial (n=24) investigated the use of FES in multiple sclerosis (Paul, 2008). Although the results of this study suggested that FES had a beneficial effect, the authors agreed that additional, larger trials were needed to support the outcomes. Esnouf and colleagues (2010) measured participant satisfaction and improvement in activities of daily living in a small randomized controlled trial of 64 people with multiple sclerosis with unilateral dropped foot. The authors concluded that highest gains in satisfaction scores were recorded with improvements in being able to walk further while using the ODFS device, however, there was no training effect recorded over the period of the intervention, and “the long-term training benefit recorded by the exercise group may not have impacted on the activities of daily living to the same extent as the more immediate assistance provided by the ODFS.” Limitations of this study include the small number of subjects reporting similar problems in each performance measure category (that is, tripping, climbing stairs, balance, walking distance, and steps and curbs) and a 17% participant drop-out rate.

Miller and colleagues (2017) performed a systematic review and meta-analysis of the effect of FES on gait speed in short and long walking performance tests in individuals with multiple sclerosis-associated foot drop. A total of 19 observational (one case-control, 8 interrupted time series) or experimental (one randomized controlled trial, one randomized crossover trial, and eight non-randomized control trials) studies (n=490 participants) were identified and rated as “moderate or weak” in design; all studies were rated “weak” for blinding. Sample numbers in most studies were generally small and ranged from 2 participants to 39 participants. One retrospective observational study included data from 153 participants. Meta-analyses of the short walk tests showed a significant initial and ongoing orthotic effect up to 20 weeks (t=2.14 [p=0.016]; t=2.81 [p=0.003], respectively). Walking speed increased by a mean of .05m/s for the initial orthotic effect and .08m/s (11.3%) and for the ongoing orthotic effect. Six studies (n= 244 participants) were included in the meta-analysis for the therapeutic effect of FES on gait speed. Pooled data analysis found no change in gait speed (no therapeutic effect) in short walking performance tests (t=0.03; p=0.487) with FES. There was a small non-significant increase in gait speed of .02m/s (3.3%) for the initial orthotic effect (n=89 participants) (t=0.57; p=0.286) and a small non-significant increase of .04m/s (6.2%) for ongoing continued orthotic effect of up to 20 weeks (n=81 participants) (t=0.94; p=0.174) with FES. Only three studies (n=61 participants) included data to evaluate the therapeutic effect of FES on gait speed in long walking performance tests up to 20 weeks. There was a 10.3% increase in walking speed noted; however, this was nonsignificant (t=1.34; p=0.091). Limitations of this meta-analysis include the low methodologic quality and contradictory results identified across the studies. Most articles did not report on the type of multiple sclerosis, which may limit the external validity of the findings. Only one interventional study reported on treatment effects beyond 24 weeks; therefore, the results are only applicable to short or moderate follow-up outcomes.

Nonprogressive and Secondary Progressive Disorders and Walking Speed

Stein and colleagues (2010) compared the orthotic and therapeutic effects of the WalkAide (Innovative Neurotronics, Austin, TX) stimulator on walking performance of subjects with chronic nonprogressive (n=41, with stroke, SCI, head injury, or cerebral palsy) and progressive (n=32, with secondary progressive multiple sclerosis or familial spastic paraparesis) disorders resulting in foot drop. After 3 months of FES use, the nonprogressive and progressive groups had a similar, significant orthotic effect (5.0% and 5.7%, respectively; p<0.003, percentage change in mean values) and therapeutic effect with FES off (17.8% and 9.1%, respectively; p<0.005) on figure-8 walking speed. The therapeutic effect on figure-8 speed diverged later between both groups to 28.0% (p<0.001) and 7.9% at 11 months. While the nonprogressive group continued to increase speed with and without stimulation, a plateau of gait speed with a tendency to a decline in speed occurred in the progressive group as a whole. The authors suggested that the decrease in walking speed may have resulted from weakening of other muscle groups that were not being stimulated. There was a significant difference in the use of the WalkAide by the progressive group compared to the nonprogressive group (p=0.037). The study limitations include the small heterogeneous participant population, lack of randomization and a control group, and short-term follow-up.

Everaert and colleagues (2010) conducted a small study on a subgroup (n=36) of the participant population to determine the effect of long-term use of the WalkAide on “residual corticospinal connections in those with central nervous system disorders.” A total of 10 participants with nonprogressive disorders (for example, stroke) and 26 with progressive disorders (for example, multiple sclerosis) used the WalkAide for 3 to 12 months. Significant improvement was reported in walking speed with the WalkAide stimulator off in both the nonprogressive group (24%) and the progressive group (7%) (p=0.008 and p=0.014, respectively). The authors concluded that increases in maximum voluntary contraction (MVC) and motor-evoked potential (MEP) suggest that regular use of the WalkAide may explain the improved voluntary control over the tibialis anterior muscle and a therapeutic effect on walking speed.

Bethoux and colleagues (2014) conducted an industry-sponsored randomized controlled trial comparing use of the WalkAide with an AFO that included 495 Medicare-eligible individuals who were at least 6 months post stroke. A total of 399 individuals completed the 6-month study. Primary outcome measures were the 10-Meter Walk Test (10MWT), a composite measure of daily function, and device-related serious adverse events. There were seven secondary outcome measures that assessed function and quality of life. Intention-to-treat analysis found that both groups improved walking performance over the 6 months of the study, and the WalkAide device was noninferior to the AFO on the primary outcome measures. Only the WalkAide group showed significant improvements from baseline to 6 months on several secondary outcome measures; however, there were no significant between-group differences for any of the outcomes.

SCI and Walking Speed

Overground walking speed and distance using four locomotor training regimens was evaluated by Field-Fote and Roach (2011) in individuals with chronic motor incomplete SCI. A total of 74 participants were randomized to one of the following training regimens for 5 days per week for 12 weeks: treadmill-based training with manual assistance (TM) (n=19), treadmill-based training with bilateral electrical stimulation (TS) (Digitimer DS7AH, Digitimer Ltd, Welwyn Garden City, Herts, UK) (n=22), overground training with electrical stimulation (OG) (n=18) (WalkAide), and treadmill-based training with locomotor robot (LR) (Lokomat Robotic Gait Orthosis, Zurich, Switzerland) (n=15). Only 10 participants were available for an average 20.3 month follow-up (4 OG and 6 in the other groups). There was a statistically significant improvement in walking speed (p<0.001) in the TM, TS and OG groups and overall time effect on training (p<0.0001). There was a significant improvement in walking distance in the TS and OG groups, with greater distance gained in the OG group. The authors identified several limitations in the study including: 1) they did not know if the training dosage was optimal for improving walking speed and distance; 2) participants were focused on walking speed during training rather than on other aspects of walking; 3) all but a few of the participants used a wheelchair as their primary means of mobility and did not ambulate in the community; and, 4) “the training parameters used in the robotic gait orthosis approach were configured to impose a kinematically appropriate gait pattern, and stepping proceeded regardless of whether participants contributed effort.” Other limitations of this study include the short-term follow-up, a significant number of participants lost to follow-up, and the heterogeneity of the study population.

Cerebral Palsy-associated Foot Drop

Meilahn (2013) assessed the tolerability and efficacy of the WalkAide neuroprosthesis in a small observational study of 10 children (7 to 12 years old) with hemiparetic cerebral palsy who used an AFO for correction of foot drop. The children tolerated the fitting and wore the device for the first 6 weeks. The mean wear time was 8.4 hours per day in the first 3 weeks and 5.8 hours per day in the next 3 weeks. A total of 7 children (70%) wore the device for the 3-month study period, with average use of 2.3 hours daily (range, 1.0 to 6.3 hours/day); 6 children (60%) continued to use the WalkAide device after study completion. Gait analysis was performed, but quantitative results were not included in the report. Although half of the children were reported to have improved gait velocity, mean velocity was relatively unchanged with the WalkAide device. Limitations of this study include the small sample size and self-selection of study participants based on their willingness to try the device.

Prosser and colleagues (2012) examined the acceptability and effectiveness of the WalkAide neuroprosthesis in 21 children with cerebral palsy who had mild gait impairments and unilateral foot drop. A total of 3 children did not experience an improvement in walking and did not complete the study. Gait analysis in the remaining 18 children showed improved dorsiflexion when compared to baseline. There was no significant change in other gait parameters, including walking speed. The average daily use was 5.6 hours (range, 1.5 to 9.4) over the 3 months of the study, although the participants had been instructed to use the device for at least 6 hours per day. A total of 18 children (86%) chose to keep using the device after the 3-month trial period. Data from this period were collected but not reported. Results of this small study should be considered preliminary, since no gains were reported in walking speed with the device. In addition, no direct comparisons with AFO use were studied, as only 1 participant wore an AFO at the time of the initial FES use. Additional study is needed in a larger number of subjects over a longer duration to permit conclusions concerning the effect of the WalkAide device on improving gait impairments and foot drop in children with cerebral palsy.

Threshold Electrical Stimulation

TES as a treatment of scoliosis was widely investigated in the 1980s. However, retrospective studies suggested that the outcomes associated with electrical stimulation were not significantly different than the natural history of scoliosis. Nachemson and Peterson (1995) published the results of a prospective study comparing the outcomes of bracing and electrical stimulation to those of untreated individuals. While those treated with bracing reported improved results, those treated with electrical stimulation did not. Since that time many scoliosis experts have abandoned electrical stimulation.

Studies conflict as to whether TES shows net benefit as a treatment for cerebral palsy and other motor disorders. One randomized controlled trial of individuals with cerebral palsy, who had previously undergone selective rhizotomy, appeared to depict a net improvement in motor function from TES (Steinbock, 1997); however, other randomized controlled trials using TES in individuals with cerebral palsy failed to show any objective clinical benefit (Dali, 2002; Kerr, 2006; van der Linden, 2003). Cauraugh and colleagues (2010) conducted a systematic review and meta-analysis using the International Classification of Functioning to determine the summary effect of electrical stimulation on impairment and activity limitations relevant to gait problems of children with cerebral palsy. The authors cited reservation about recommending electrical stimulation as an efficacious intervention for individuals with cerebral palsy. Outside of the laboratory-testing experiments, “no quantitative, functional immediate or longitudinal effects beyond the testing situations were reported in the studies. Thus, long-term effects of various types of electrical stimulation on gait challenges in children with cerebral palsy would advance our understanding.”


FES attempts to replace stimuli from destroyed nerve pathways with computer-controlled sequential electrical stimulation of muscles to enable individuals with SCI or stroke to function independently, or at least maintain healthy muscle tone and strength. This is in contrast to the use of neuromuscular stimulation for disuse atrophy when the nerve supply to the muscle is intact.

FES Devices Used for General Rehabilitation

The ERGYS (Therapeutic Alliances Inc., Fairborn, Ohio) is a medical device categorized as a powered muscle stimulator by the U.S. Food and Drug Administration (FDA). Computer generated, low-level electrical pulses transmitted through surface electrodes cause coordinated contractions of the large muscles of the legs. Sensors located in the ERGYS provide continuous feedback to a computer which controls the sequence of muscle contractions as well as the resistance to pedaling. The RT300 device (Restorative Therapies, Inc., Baltimore, MD) received FDA 510(k) marketing clearance on June 27, 2005 as a FES cycle ergometer device with models designed for pediatric (ages 4 to 12 years) and adult use (that is, RT300 Leg, RT300 Leg and Arm, RT300 Arm, RT300-SP for children). These Class II devices are powered muscle stimulators for general rehabilitation for relaxation of muscle spasms, prevention or retardation of disuse atrophy, increasing local blood circulation and maintaining or increasing range of motion. On April 4, 2011, the RT600 FES stepper ergometer received 510(k) clearance as a substantially equivalent device to the predicate RT300 FES device for use in individuals 12 years of age and older.

FES Devices Used for Ambulation

The Parastep Ambulation System (Parastep I) is an ambulation FES device approved by the FDA in 1994. The premarket approval (PMA) document states the Parastep-I device:

enables appropriately selected skeletally mature spinal cord injured individuals (level C6-T12) to stand and attain limited ambulation and/or take steps, with assistance if required, following a prescribed period of physical therapy training in conjunction with rehabilitation management of spinal cord injury.

According to the device manufacturer, the system is designed to provide up to six channels of stimulation, stimulating up to three muscle groups on the side of each leg. Some individuals may require only four channels of stimulation to stand and ambulate, where electrical stimulation is directed to four electrodes on each lower extremity. Stimulation of the quadriceps muscles results in knee extension, enabling the user to stand. Stimulation of the peroneal nerve in the lower extremity initiates a triple-flexion reflex response, resulting in contraction of muscles to flex the hip, knee, and ankle, which lifts the foot off the floor. Subsequent quadriceps stimulation extends the knee in preparation for heel-strike and weight bearing. When six channels of stimulation are used, electrical stimulation is directed to the previously mentioned sites and to two additional electrodes on each hip. Stimulation of gluteal muscles extends the hips, contributing to stability while standing and taking steps. In addition, the individual uses a walker or elbow-support crutches for further support. The electrical impulses are controlled by a computer microchip attached to the individual’s belt that synchronizes and distributes the signals. Finally, there is a finger-controlled switch that permits activation of the stepping device by the individual.

Other devices include a reciprocating gait orthosis (RGO) with electrical stimulation. The orthosis used is a rather cumbersome hip-knee-ankle-foot device linked together with a cable at the hip joint. FES has been adapted to use with the RGO as a hybrid device.

FES Devices for Other Indications

Devices used to treat foot drop include the WalkAide, the NESS L300 Foot Drop System (Bioness, Inc, Valencia, CA), and the ODFS Dropped Foot Stimulator/ODFS Pace. The devices consist of a gait sensor, leg cuff and hand held control. When the heel lifts, signals from the gait sensor are sent to the stimulation unit in the leg cuff that stimulates the common peroneal nerve that innervates the tibialis anterior muscles, which in turn lifts the foot while walking. The WalkAide device first received 510(k) marketing clearance from the FDA in the 1990s with subsequent upgrades to the system. The Bioness NESS L300 received 510(k) marketing clearance in July 2006. The ODFS Dropped Foot Stimulator received 510(k) marketing clearance on July 15, 2005. The ODFS Pace received 510(k) clearance as a substantially equivalent device on March 30, 2011. The FDA summaries for these devices state that they are intended for use in individuals with drop foot by assisting with ankle dorsiflexion during the swing phase of gait.

There are multiple FDA 510K marketing clearances for functional neuromuscular stimulators for use on the hand and forearm. These include the NESS Neuromuscular Electrical Stimulation Systems Handmaster (K010837, K012823, and K031900). The FDA has also approved the NESS System Powered Muscle Stimulator (K022776) for use at sites on the limbs other than the hand. The NESS Systems are portable, one-channel electrical neuromuscular stimulators. The stimulators are powered by rechargeable batteries. Surface electrodes are held on to the limb by a splint. Electrical stimulation is delivered to the muscles through the surface electrodes. The NESS H200 Hand Rehabilitation System is designed to stimulate the extensor and flexor muscle of the forearm as well as the ulnar muscle of the hand. The stimulation is intended to provide hand active range of motion and hand function for individuals with upper limb paralysis due to C5 SCI or hemiplegia due to stroke.


TES or therapeutic electrical stimulation involves the delivery of low intensity electrical stimulation (typically at night) and has been investigated as a treatment of scoliosis. Stimulation is applied to the convex side of the curvature in order to evoke muscle contractions causing curvature correction. Electrical stimulation may be one component of an overall non-surgical treatment program for scoliosis. For example, the Scoliosis Treatment Recovery System, which includes the Copes Scoliosis Dynamic Brace, also includes electrical stimulation as part of the treatment program. For individuals with cerebral palsy, threshold electrical stimulation is designed to increase muscle strength and joint mobility leading to improved voluntary motor function.


Cerebral palsy: A persistent qualitative motor disorder appearing before the age of 3 years due to non-progressive damage to the brain.

Disuse atrophy: A wasting or loss of size of a part of the body because of disease or other influences.

Functional electrical stimulation (FES): A rehabilitation technique where a low-level electrical current is applied to muscles of a neurologically impaired individual in an attempt to replace stimuli from destroyed nerve pathways and enhance that person’s ability to maintain healthy muscle tone and strength to function independently.

Scoliosis: A congenital lateral curvature of the spine.

Threshold (or therapeutic) electrical stimulation (TES): A form of low-intensity electrical stimulation that attempts to strengthen muscles weakened by non-use.


The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

Functional Electrical Stimulators
When services are Investigational and Not Medically Necessary:




Functional neuromuscular stimulator, transcutaneous stimulation of sequential muscle groups of ambulation with computer control, used for walking by spinal cord injured, entire system, after completion of training program


Functional electrical stimulator, transcutaneous stimulation of nerve and/or muscle groups, any type, complete system, not otherwise specified  [e.g., NESS L300, WalkAide device, NESS H200]



ICD-10 Diagnosis



All diagnoses

Threshold Electrical Stimulators
When services are Investigational and Not Medically Necessary:




For the following codes when specified as a threshold electrical stimulator device:


Neuromuscular stimulator, electronic shock unit


Durable medical equipment, miscellaneous



ICD-10 Diagnosis



Cerebral palsy


Hemiplegia and hemiparesis, paraplegia and quadriplegia

G83.0- G83.34

Diplegia, monoplegia of limbs


Locked-in state


Other specified paralytic syndromes, paralytic syndrome unspecified


Monoplegia of limb, hemiplegia and hemiparesis, other paralytic syndrome following nontraumatic subarachnoid hemorrhage


Monoplegia of limb, hemiplegia and hemiparesis, other paralytic syndrome following nontraumatic intracerebral hemorrhage


Monoplegia of limb, hemiplegia and hemiparesis, other paralytic syndrome following nontraumatic intracranial hemorrhage


Monoplegia of limb, hemiplegia and hemiparesis, other paralytic syndrome following cerebral infarction


Monoplegia of limb, hemiplegia and hemiparesis, other paralytic syndrome following other cerebrovascular disease


Monoplegia of limb, hemiplegia and hemiparesis, other paralytic syndrome following unspecified cerebrovascular disease


Kyphosis and lordosis


Scoliosis, spinal osteochondrosis, other deforming dorsopathies


Abnormalities of gait and mobility


Other and unspecified injuries of cervical spinal cord, sequela [by level; includes codes S14.101S, S14.102S, S14.103S, S14.104S, S14.105S, S14.106S, S14.107S, S14.108S, S14.109S, S14.111S, S14.112S, S14.113S, S14.114S, S14.115S, S14.116S, S14.117S, S14.118S, S14.119S, S14.121S, S14.122S, S14.123S, S14.124S, S14.125S, S14.126S, S14.127S, S14.128S, S14.129S, S14.131S, S14.132S, S14.133S, S14.134S, S14.135S, S14.136S, S14.137S, S14.138S, S14.139S, S14.141S, S14.142S, S14.143S, S14.144S, S14.145S, S14.146S, S14.147S, S14.148S, S14.149S, S14.151S, S14.152S, S14.153S, S14.154S, S14.155S, S14.156S, S14.157S, S14.158S, S14.159S]


Other and unspecified injuries of thoracic spinal cord, sequela [by level, includes codes S24.101S, S24.102S, S24.103S, S24.104S, S24.109S, S24.111S, S24.112S, S24.113S, S24.114S, S24.119S, S24.131S, S24.132S, S24.133S, S24.134S, S24.139S, S24.141S, S24.142S, S24.143S, S24.144S, S24.149S, S24.151S, S24.152S, S24.153S, S24.154S, S24.159S]


Other and unspecified injury of lumbar and sacral spinal cord, sequela [by level, includes codes S34.101S, S34.102S, S34.103S, S34.104S, S34.105S, S34.109S, S34.111S, S34.112S, S34.113S, S34.114S, S34.115S, S34.119S, S34.121S, S34.122S, S34.123S, S34.124S, S34.125S, S34.129S, S34.131S, S34.132S, S34.139S]


Peer Reviewed Publications:

  1. Alon G, McBride K. Persons with C5 or C6 tetraplegia achieve selected functional gains using a neuroprosthesis. Arch Phys Med Rehabil. 2003; 84(1):119-124.
  2. Ambrosini E, Ferrante S, Pedrocchi A, et al. Cycling induced by electrical stimulation improves motor recovery in postacute hemiparetic patients: a randomized controlled trial. Stroke. 2011; 42(4):1068-1073.
  3. Barrett CL, Mann GE, Taylor PN, Strike P. A randomized trial to investigate the effects of functional electrical stimulation and therapeutic exercise on walking performance for people with multiple sclerosis. Mult Scler. 2009; 15(4):493-504.
  4. Berry HR, Kakebeeke TH, Donaldson N, et al. Energetics of paraplegic cycling: adaptations to 12 months of high volume training. Technol Health Care. 2012; 20(2):73-84.
  5. Bethoux F, Rogers HL, Nolan KJ, et al. The effects of peroneal nerve functional electrical stimulation versus ankle-foot orthosis in patients with chronic stroke: a randomized controlled trial. Neurorehabil Neural Repair. 2014; 28(7):688-697.
  6. Brissot R, Gallien P, Le Bot MP, et al. Clinical experience with functional electrical stimulation-assisted gait with Parastep in spinal cord-injured patients. Spine. 2000; 25(4):501-508.
  7. Cauraugh JH, Naik SK, Hsu WH, et al. Children with cerebral palsy: a systematic review and meta-analysis on gait and electrical stimulation. Clin Rehabil. 2010; 24(11):963-978.
  8. Chan MK, Tong RK, Chung KY. Bilateral upper limb training with functional electric stimulation in patients with chronic stroke. Neurorehabil Neural Repair. 2009; 23(4):357-365.
  9. Chaplin E. Functional neuromuscular stimulation for mobility in people with spinal cord injuries. The Parastep I System. J Spinal Cord Med 1996; 19(2):99-105.
  10. Cheng JS, Yang YR, Cheng SJ, et al. Effects of combining electric stimulation with active ankle dorsiflexion while standing on a rocker board: a pilot study for subjects with spastic foot after stroke. Arch Phys Med Rehabil. 2010; 91(4):505-512.
  11. Craven BC, Giangregorio LM, Alavinia SM, et al. Evaluating the efficacy of functional electrical stimulation therapy assisted walking after chronic motor incomplete spinal cord injury: effects on bone biomarkers and bone strength. J Spinal Cord Med. 2017; 40(6):748-758.
  12. Dali C, Hansen FJ, Pedersen SA, et al. Threshold electrical stimulation (TES) in ambulant children with CP: a randomized double-blind placebo-controlled clinical trial. Dev Med Child Neurol. 2002; 44(6):364-369.
  13. Daly, JJ, Roenigk K, Holcomb J, et al. A randomized controlled trial of functional neuromuscular stimulation in chronic stroke subjects. Stroke. 2006; 37(1):172-178.
  14. Daly JJ, Zimbelman J, Roenigk KL, et al. Recovery of coordinated gait: randomized controlled stroke trial of functional electrical stimulation (FES) versus no FES, with weight-supported treadmill and over-ground training. Neurorehabil Neural Repair. 2011; 25(7):588-596.
  15. Embrey DG, Holtz SL, Alon G, et al. Functional electrical stimulation to dorsiflexors and plantar flexors during gait to improve walking in adults with chronic hemiplegia. Arch Phys Med Rehabil. 2010; 91(5):687-696.
  16. Eraifej J, Clark W, France B, et al. Effectiveness of upper limb functional electrical stimulation after stroke for the improvement of activities of daily living and motor function: a systematic review and meta-analysis. Syst Rev. 2017; 6(1):40.
  17. Esnouf JE, Taylor PN, Mann GE, Barrett CL. Impact on activities of daily living using a functional electrical stimulation device to improve dropped foot in people with multiple sclerosis, measured by the Canadian Occupational Performance Measure. Mult Scler. 2010; 16(9):1141-1147.
  18. Everaert DG, Thompson AK, Chong SL, Stein RB. Does functional electrical stimulation for foot drop strengthen corticospinal connections? Neurorehabil Neural Repair. 2010; 24(2):168-177.
  19. Faghri PD, Glaser RM, Figoni SF. Functional electrical stimulation leg cycle ergometer exercise: training effects on cardiorespiratory responses of spinal cord injured subjects at rest and during submaximal exercise. Arch Phys Med Rehabil. 1992; 73(11):1085-1093.
  20. Field-Fote EC, Roach KE. Influence of a locomotor training approach on walking speed and distance in people with chronic spinal cord injury: a randomized clinical trial. Phys Ther. 2011; 91(1):48-60.
  21. Giangregorio L, Craven C, Richards K, et al. A randomized trial of functional electrical stimulation for walking in incomplete spinal cord injury: effects on body composition. J Spinal Cord Med. 2012; 35(5):351-360.
  22. Graupe D, Kohn KH. Functional neuromuscular stimulator for short-distance ambulation by certain thoracic-level spinal-cord-injured paraplegics. Surg Neurol. 1998; 50(3):202-207.
  23. Gu P, Ran JJ. Electrical stimulation for hemiplegic shoulder function: a systematic review and meta-analysis of 15 randomized controlled trials. Arch Phys Med Rehabil. 2016; 97(9):1588-1594.
  24. Guest RS, Klose J, Needham-Shropshire BM, et al. Evaluation of a training program for persons with SCI paraplegia using the Parastep®1 Ambulation System: part 4. Arch Phys Med Rehabil. 1997; 78(8):804-807.
  25. Harvey LA, Dunlop SA, Churilov L, Galea MP. Early intensive hand rehabilitation is not more effective than usual care plus one-to-one hand therapy in people with sub-acute spinal cord injury ('Hands On'): a randomised trial. J Physiother. 2016; 62(2):88-95.
  26. Hausdorff JM, Ring H. Effects of a new radio frequency-controlled neuroprosthesis on gait symmetry and rhythmicity in patients with chronic hemiparesis. Am J Phys Med Rehabil. 2008; 87(1):4-13.
  27. Hendricks HT, IJzerman MJ, de Kroon JR, et al. Functional electrical stimulation by means of the ‘Ness Handmaster Orthosis’ in chronic stroke patients: an exploratory study. Clin Rehabil. 2001; 15(2):217-220.
  28. Jacobs PL, Nash MS, Klose KJ, et al. Evaluation of a training program for persons with SCI paraplegia using the Parastep 1 ambulation system: part 2. Effects on physiologic responses to peak arm ergonometry. Arch Phys Med Rehabil. 1997; 78(8):794-798.
  29. Janssen TW, Beltman JM, Elich P, et al. Effects of electric stimulation-assisted cycling training in people with chronic stroke. Arch Phys Med Rehabil. 2008; 89(3):463-469.
  30. Johnston TE, Betz RR, Smith BT, Mulcahey MJ. Implanted functional electrical stimulation: an alternative for standing and walking in pediatric spinal cord injury. Spinal Cord. 2003; 41(3):144-152.
  31. Johnston TE, Modlesky CM, Betz RR, Lauer RT. Muscle changes following cycling  and/or electrical stimulation in pediatric spinal cord injury. Arch Phys Med Rehabil. 2011; 92(12):1937-1943.
  32. Johnston TE, Smith BT, Mulcahey MJ, et al. A randomized controlled trial on the effects of cycling with and without electrical stimulation on cardiorespiratory and vascular health in children with spinal cord injury. Arch Phys Med Rehabil. 2009; 90(8):1379-1388.
  33. Kafri M, Laufer Y. Therapeutic effects of functional electrical stimulation on gait in individuals post-stroke. Ann Biomed Eng. 2015; 43(2):451-466.
  34. Khamis S, Herman T, Krimus S, Danino B. Is functional electrical stimulation an alternative for orthotics in patients with cerebral palsy? A literature review. Eur J Paediatr Neurol. 2018; 22(1):7-16.
  35. Kern H, Carraro U, Adami N, et al. Home-based functional electrical stimulation rescues permanently denervated muscles in paraplegic patients with complete lower motor neuron lesion. Neurorehabil Neural Repair. 2010; 24(8):709-721.
  36. Kerr C, McDowell B, Cosgrove A, et al. Electrical stimulation in cerebral palsy: a randomized controlled trial. Dev Med Child Neurol. 2006; 48(11):870-876.
  37. Kluding PM, Dunning K, O'Dell MW, et al. Foot drop stimulation versus ankle foot orthosis after stroke: 30-week outcomes. Stroke. 2013; 44(6):1660-1669.
  38. Kottink AI, Hermens HJ, Nene AV, et al. A randomized controlled trial of an implantable 2-channel peroneal nerve stimulator on walking speed and activity in poststroke hemiplegia. Arch Phys Med Rehabil. 2007; 88(8):971-978.
  39. Koyuncu E, Nakipoglu-Yuzer GF, Dogan A, Ozgirgin N. The effectiveness of functional electrical stimulation for the treatment of shoulder subluxation and shoulder pain in hemiplegic patients: a randomized controlled trial. Disabil Rehabil. 2010; 32(7):560-566.
  40. Lauer RT, Smith BT, Mulcahey MJ, et al. Effects of cycling and/or electrical stimulation on bone mineral density in children with spinal cord injury. Spinal Cord. 2011; 49(8):917-923.
  41. Martin R, Sadowsky C, Obst K, et al. Functional electrical stimulation in spinal cord injury: from theory to practice. Top Spinal Cord Inj Rehabil. 2012; 18(1):28-33.
  42. Meijer JW, Voerman GE, Santegoets KM, Geurts AC. Short-term effects and long-term use of hybrid orthosis for neuromuscular electrical stimulation of the upper extremity in patients after chronic stroke. J Rehabil Med. 2009; 41(3):157-161.
  43. Meilahn JR. Tolerability and effectiveness of a neuroprosthesis for the treatment of footdrop in pediatric patients with hemiparetic cerebral palsy. PM&R. 2013; 5(6):503-509.
  44. Miller L, McFadyen A, Lord AC, et al. Functional electrical stimulation for foot drop in multiple sclerosis: a systematic review and meta-analysis of the effect on gait speed. Arch Phys Med Rehabil. 2017; 98(7):1435-1452.
  45. Moll I, Vles JSH, Soudant DLHM, et al. Functional electrical stimulation of the ankle dorsiflexors during walking in spastic cerebral palsy: a systematic review. Dev Med Child Neurol. 2017; 59(12):1230-1236.
  46. Nachemson AL, Peterson LE. Effectiveness of treatment with a brace in girls who have adolescent idiopathic scoliosis. A prospective, controlled study based on data from the Brace Study of the Scoliosis Research Society. J Bone Joint Surg Am. 1995; 77(6):815-822.
  47. Nash MS, Jacobs PL, Montalvo BM, et al. Evaluation of a training program for persons with SCI paraplegia using the Parastep®1 Ambulation System: part 5. Arch Phys Med Rehabil. 1997; 78(8):808-814.
  48. Needham-Shropshire BM, Broton JG, Klose KJ, et al. Evaluation of a training program for persons with SCI paraplegia using the Parastep®1 Ambulation System: Part 3. Arch Phys Med Rehabil. 1997; 78(8):799-803.
  49. O'Dell MW, Dunning K, Kluding P, et al. Response and prediction of improvement in gait speed from functional electrical stimulation in persons with poststroke drop foot. PM&R. 2014; 6(7):587-601.
  50. Paul L, Rafferty D, Young S, et al. The effect of functional electrical stimulation on the physiologic cost of gait in people with multiple sclerosis. Multiple Sclerosis. 2008; 14(7): 954-961.
  51. Pereira S, Mehta S, McIntyre A, et al. Functional electrical stimulation for improving gait in persons with chronic stroke. Top Stroke Rehabil. 2012; 9(6):491-498.
  52. Prenton S, Hollands KL, Kenney LP. Functional electrical stimulation versus ankle foot orthoses for foot-drop: a meta-analysis of orthotic effects. J Rehabil Med. 2016; 48(8):646-656.
  53. Prosser LA, Curatalo LA, Alter KE, et al. Acceptability and potential effectiveness of a foot drop stimulator in children and adolescents with cerebral palsy. Dev Med Child Neurol. 2012; 54(11):1044-1049.
  54. Ring H, Rosenthal N. Controlled study of neuroprosthetic functional electrical stimulation in sub-acute post-stroke rehabilitation. J Rehabil Med. 2005; 37(1):32-36.
  55. Ring H, Treger I, Gruendlinger L, Hausdorff JM. Neuroprosthesis for footdrop compared with an ankle-foot orthosis: effects on postural control during walking. J Stroke Cerebrovasc Dis. 2009; 18(1):41-47.
  56. Sabut SK, Lenka PK, Kumar R, Mahadevappa M. Effect of functional electrical stimulation on the effort and walking speed, surface electromyography activity, and metabolic responses in stroke subjects. J Electromyogr Kinesiol. 2010a; 20(6):1170-1177.
  57. Sabut SK, Sikdar C, Mondal R, et al. Restoration of gait and  motor recovery by functional electrical stimulation therapy in persons with stroke. Disabil Rehabil. 2010b; 32(19):1594-1603.
  58. Santos M, Zahner LH, McKiernan BJ, et al. Neuromuscular electrical stimulation improves severe hand dysfunction for individuals with chronic stroke: a pilot study. J Neurol Phys Ther. 2006; 30(4):175-183.
  59. Sheffler LR, Taylor PN, Gunzler DD, et al. Randomized controlled trial of surface peroneal nerve stimulation for motor relearning in lower limb hemiparesis. Arch Phys Med Rehabil. 2013; 94(6):1007-1014.
  60. Snoek GJ, Ijzerman MJ, Groen FA, et al. Use of the NESS Handmaster to restore hand function in tetraplegia: clinical experiences in ten patients. Spinal Cord. 2000; 38(4):244-249.
  61. Soleyman-Jahi S, Yousefian A, Maheronnaghsh R, et al. Evidence-based prevention and treatment of osteoporosis after spinal cord injury: a systematic review. Eur Spine J. 2017 May 11. [Epub ahead of print].
  62. Solomonow M, Aguilar E, Reisin E, et al. Reciprocating gait orthosis powered with electrical muscle stimulation (RGO II). Part I: Performance evaluation of 70 paraplegic patients. Orthopedics. 1997; 20(4):315-324.
  63. Solomonow M, Reisin E, Aguilar E, et al. Reciprocating gait orthosis powered with electrical muscle stimulation (RGO II). Part II: Medical evaluation of 70 paraplegic patients. Orthopedics. 1997; 20(5):411-418.
  64. Springer S, Vatine JJ, Lipson R, et al. Effects of dual-channel functional electrical stimulation on gait performance in patients with hemiparesis. ScientificWorldJournal. 2012; 2012:530906.
  65. Springer S, Vatine JJ, Wolf A, Laufer Y. The effects of dual-channel functional electrical stimulation on stance phase sagittal kinematics in patients with hemiparesis. J Electromyogr Kinesiol. 2013; 23(2):476-482.
  66. Stein RB, Everaert DG, Thompson AK, et al. Long-term therapeutic and orthotic effects of a foot drop stimulator on walking performance in progressive and nonprogressive neurological disorders. Neurorehabil Neural Repair. 2010; 24(2):152-167.
  67. Steinbok P, Reiner A, Kestle JR. Therapeutic electrical stimulation following selective posterior rhizotomy in children with spastic diplegic cerebral palsy: a randomized clinical trial. Dev Med Child Neurol. 1997; 39(8):515-520.
  68. Sullivan JE, Hedman LD. Effects of home-based sensory and motor amplitude electrical stimulation on arm dysfunction in chronic stroke. Clin Rehabil. 2007; 21(2):142-150.
  69. Sykes L, Ross ER, Powell ES, et al. Objective measurement of use of the reciprocating gait orthosis (RGO) and the electrically augmented RGO in adult patients with spinal cord lesions. Prosthet Orthot Int. 1996; 20(3):182-190.
  70. Taylor PN, Burridge JH, Dunkerley AL, et al. Clinical use of the Odstock dropped foot stimulator: its effect on the speed and effort of walking. Arch Phys Med Rehabil. 1999; 80(12):1577-1583.
  71. Vafadar AK, Cote JN, Archambault PS. Effectiveness of functional electrical stimulation in improving clinical outcomes in the upper arm following stroke: a systematic review and meta-analysis. Biomed Res Int. 2015; 2015:729768.
  72. van der Linden ML, Hazlewood ME, Aitchison AM, et al. Electrical stimulation of gluteus maximus in children with cerebral palsy: effects on gait characteristics and muscle strength. Dev Med Child Neurol. 2003; 45(6):385-390.
  73. Weingarden HP, Zeilig G, Heruti R, et al. Hybrid functional electrical stimulation orthosis system for the upper limb: effects on spasticity in chronic stable hemiplegia. Am J Phys Med Rehabil. 1998; 77(4):276-281.

Government Agency, Medical Society, and Other Authoritative Publications:

  1. Centers for Medicare and Medicaid Services (CMS). National Coverage Determinations. Available at: Accessed on March 13, 2018.
    • Neuromuscular Electrical Stimulation (NMES). NCD #160.12. Effective October 1, 2006.
    • Treatment of Motor Function Disorders with Electric Nerve Stimulation. NCD #160.2. Effective April 1, 2003.
  2. Pomeroy VM, King L, Pollock A, et al. Electrostimulation for promoting recovery of movement or functional ability after stroke. Cochrane Database Syst Rev. 2006;(2):CD00324.
Websites for Additional Information
  1. National Institute of Health (NIH): National Institute of Neurological Disorders and Stroke (NINDS). All Disorder Index. Available at: Accessed on March 13, 2018.

FES Bike
NESS H200 System
NESS L300 Foot Drop System
NESS L300 Plus System
ODFS-Odstock Dropped Foot Stimulator
Parastep I System
RT300 FES Cycle Ergometer
RT300/300S Systems
RT300-SL Therapy Rehabilitation System
RT600 Step and Stand Rehabilitation Therapy System

The use of specific product names is illustrative only.  It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available. 

Document History






Medical Policy & Technology Assessment Committee (MPTAC) review. The document header wording updated from “Current Effective Date” to “Publish Date.” Updated Rationale, References, and Websites for Additional Information sections.



MPTAC review. Updated formatting in Position Statement section. Updated Rationale, Background, References, Websites for Additional Information, and Index sections.



MPTAC review. Minor format changes to the Rationale section. Removed ICD-9 codes from Coding section.



MPTAC review. Updated Rationale, References, and Websites for Additional information sections. Format changes throughout document.



MPTAC review. Minor format changes. Updated Rationale, References, and Websites for Additional Information sections.



MPTAC review. Minor format changes. Updated Description, Rationale, References, Websites for Additional Information, and Index.



MPTAC review. Updated Description, Rationale, Background, Coding, References, Websites for Additional Information and Index.



MPTAC review. Updated Rationale, References and Websites for Additional Information.



MPTAC recommendation to revise text in the Background/Discussion section, Functional Electrical Stimulation: Devices Used for Ambulation, that describes the stimulation of the peroneal nerve when the individual utilizes the Parastep-I device.



MPTAC review. Updated Rationale, including FES for upper extremity conditions/chronic post stroke hemiparesis and foot drop, multiple sclerosis and cerebral palsy. Updated References and Index.  



MPTAC review. Clarified investigational and not medically statement for functional electrical stimulation when used to activate muscles of the upper limb to produce functional movement patterns, adding lower limb to the current statement; updated device names. Revised Description, Rationale, Discussion, and Definitions. Updated References and Index with device information.



Updated Coding section with 01/01/2009 HCPCS changes.



MPTAC review. Description and References updated.



The phrase "investigational/not medically necessary" was clarified to read "investigational and not medically necessary." This change was approved at the November 29, 2007 MPTAC meeting.



MPTAC review. Added FES of the upper limb to produce functional movement patterns as investigational/not medically necessary. Coding updated; removed HCPCS K0600 deleted 12/31/2005.



MPTAC review. References and Coding updated.



Updated Coding section with 01/01/2006 CPT/HCPCS changes



Added reference for Centers for Medicare and Medicaid Services (CMS) – National Coverage Determination (NCD).



MPTAC review.  Revision based on Pre-merger Anthem and Pre-merger WellPoint Harmonization. Addition of language addressing ERGYS.

Pre-Merger Organizations

Last Review Date

Document Number


Anthem, Inc.




Neuromuscular Stimulation: Functional Electrical Stimulation (FES); Threshold Electrical Stimulation (TES)

WellPoint Health Networks, Inc.



Transcutaneous Stimulation for the Treatment of Scoliosis, Cerebral Palsy and other Motor Disorders