Effect of Functional Electrical Stimulation on asymmetries in gait of children with hemiplegic cerebral palsy

Increased Asymmetry of Lower Limbs and Leading Joint Angles during Crossing Obstacles in Healthy Male with Cold Exposure

Lower ambient temperatures impair neuromuscular function and balance. However, whether lower ambient temperatures could alter joint angles and symmetry of lower limbs during crossing obstacles in males still remains unknown. Therefore, we investigated whether there is reduction of ambient temperature (20°C; 15°C; 10°C) on lower limbs joint angles and symmetry when crossing obstacles in males. On three different occasions, eighteen male participants underwent 30 min exposure to three different environmental temperatures (10°C, 15°C, and 20°C), which was followed by the obstacle crossing test at 10%, 20%, and 30% of the participant leg length. In each trial, we assessed joint angles and symmetry of lower limbs when crossing obstacles at 10%, 20%, and 30% of the participants’ leg length. The results showed that leading limb maximum joint angles were greater in 10°C than in 15°C and 20°C when leading limb crossed obstacle heights of 20% and 30% leg length ( $p<0.05$ ). Trailing limb maximum joint angles were not different ( $p>0.05$ ). Lower limb asymmetry increased when participants crossed obstacle heights of 20% and 30% leg length at 10°C ( $p<0.05$ ). This study concluded that in male participants, cold exposure can increase lower limb asymmetry to increase falling risk when crossing obstacles. Also, the increased leading limb joint angles and constant trailing limb joint angles increase safety during crossing obstacles.

Effectiveness of neuromuscular electrical stimulation in improving mobility in children with cerebral palsy: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To investigate whether neuromuscular electrical stimulation improves mobility in children with spastic cerebral palsy.

METHODS

PubMed, Cochrane, EMBASE, and Scopus were searched for randomized controlled trials studying the effects of NMES on the lower limbs in children with spastic CP. Randomized controlled trials comparing the effect of neuromuscular electrical stimulation with that of placebo or conventional therapy on mobility in children with cerebral palsy were eligible for inclusion. Two reviewers independently screened studies, extracted data, and examined the risk of bias and quality of evidence by using the revised Cochrane Risk-of-Bias Tool for Randomized Trials (RoB 2.0) and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method. The final search was conducted on May 23, 2022.

RESULTS

A total of 14 randomized controlled trials (2 crossover studies and 12 parallel studies including 421 patients) were included in this meta-analysis. Compared with the control group (conventional physical therapy), the treatment group exhibited greater improvement in walking speed (standardized mean difference = 0.29; 95% confidence interval = 0.02-0.57) and the standing, walking, running, and jumping dimension of the Gross Motor Function Measure (standardized mean difference = 1.24; 95% confidence interval = 0.64-1.83).

CONCLUSION

Neuromuscular electrical stimulation improved mobility in children with spastic cerebral palsy, particularly in standing, running, and jumping function, and it is safe for children with spastic cerebral palsy.

Acute responses to locomotor tasks differ according to gait-asymmetry patterns in children with hemiplegic cerebral palsy: An exploratory analysis

This study aimed at determining if differential responses to locomotor tasks in children with spastic hemiplegia occur on account of step-length asymmetry patterns [symmetrical step-length (S-SL); affected side short (AFF_short), and non-affected short (Non-AFF_short)] observed during on-ground walking. Thirty-two children (5-8 years) were assessed for spatial/temporal measures of gait while walking on the ground with self-selected speed. Data from on-ground walking were compared against three locomotor tasks that were examined on a treadmill: self-imposed walking velocity with bodyweight support of 0% (BWS-0%), self-imposed walking velocity with a BWS of 20% (BWS-20%), and fastest walking velocity with a BWS of 20% and a manually-guided response of the non-affected leg (MGR_non-affected). The primary outcome measures were the spatial (step length) and temporal (single-limb support time) symmetry indices. The step-length asymmetry subgroups responded differently to the locomotor tasks. The MGR_non-affected produced spatial symmetry in the S-SL and Non-AFF_short groups and temporal symmetry in the AFF_short group. The BWS-0% and BWS-20% treadmill walking conditions were insufficient to remediate either spatial or temporal walking asymmetry. In conclusion, acute responses to locomotor tasks are not consistent among asymmetry subgroups, suggesting that they might need individual treatment plans. In spite of the differences in walking characteristics between asymmetry subgroups, the improvement in gait-symmetry arose out of changes in affected and non-affected sides together.

Evaluation of Individualized Functional Electrical Stimulation-Induced Acute Changes during Walking: A Case Series in Children with Cerebral Palsy

Functional electrical stimulation (FES) walking interventions have demonstrated improvements to gait parameters; however, studies were often confined to stimulation of one or two muscle groups. Increased options such as number of muscle groups targeted, timing of stimulation delivery, and level of stimulation are needed to address subject-specific gait deviations. We aimed to demonstrate the feasibility of using a FES system with increased stimulation options during walking in children with cerebral palsy (CP). Three physical therapists designed individualized stimulation programs for six children with CP to target participant-specific gait deviations. Stimulation settings (pulse duration and current) were tuned to each participant. Participants donned our custom FES system that utilized gait phase detection to control stimulation to lower extremity muscle groups and walked on a treadmill at a self-selected speed. Motion capture data were collected during walking with and without the individualized stimulation program. Eight gait metrics and associated timing were compared between walking conditions. The prescribed participant-specific stimulation programs induced significant change towards typical gait in at least one metric for each participant with one iteration of FES-walking. FES systems with increased stimulation options have the potential to allow the physical therapist to better target the individual's gait deviations than a one size fits all device.

An Analytical Insight Into How Walking Speed and Spatial and Temporal Symmetry Are Related to Ankle Dysfunctions in Children With Hemiplegic Cerebral Palsy

OBJECTIVE

The aim of the study was to identify the major determining factors among ankle dysfunctions for walking speed and symmetry in children with hemiplegic cerebral palsy.

DESIGN

This was a prospective analysis that included 52 children with hemiplegic cerebral palsy, aged between 5 and 8 yrs, had mild spasticity, and were functioning at Gross Motor Function Classification System level I or II. The dorsiflexor and plantar flexor strength, dynamic spasticity (represented by gastrocnemius muscle lengthening velocity during stance phase), plantar flexors stiffness, ankle joint position sense, and walking performance (spatiotemporal parameter) were assessed.

RESULTS

The least absolute shrinkage and selection operator regression analyses showed that the dorsiflexor strength of the paretic limb was the major determining factor of walking speed (R2 = 0.38, P < 0.001). Dynamic spasticity of the plantar flexors explained a portion of the variance in walking speed (R2 = 0.15, P < 0.001) and the highest portion of the variance in spatial walking symmetry (R2 = 0.18, P = 0.002). In addition, the ankle joint position sense was the primary determinant of temporal walking symmetry (R2 = 0.10, P = 0.021).

CONCLUSIONS

In children with hemiplegic cerebral palsy, walking speed is mostly influenced by dorsiflexor muscle strength, temporal walking symmetry is associated with the joint position sense, whereas spatial walking symmetry is explicated by the dynamic spasticity of the plantar flexor muscles.

Toward a hybrid exoskeleton for crouch gait in children with cerebral palsy: neuromuscular electrical stimulation for improved knee extension

BACKGROUND

Neuromuscular Electrical Stimulation (NMES) has been utilized for many years in cerebral palsy (CP) with limited success despite its inherent potential for improving muscle size and/or strength, inhibiting or reducing spasticity, and enhancing motor performance during functional activities such as gait. While surface NMES has been shown to successfully improve foot drop in CP and stroke, correction of more complex gait abnormalities in CP such as flexed knee (crouch) gait remains challenging due to the level of stimulation needed for the quadriceps muscles that must be balanced with patient tolerability and the ability to deliver NMES assistance at precise times within a gait cycle.

METHODS

This paper outlines the design and evaluation of a custom, noninvasive NMES system that can trigger and adjust electrical stimulation in real-time. Further, this study demonstrates feasibility of one possible application for this digitally-controlled NMES system as a component of a pediatric robotic exoskeleton to provide on-demand stimulation to leg muscles within specific phases of the gait cycle for those with CP and other neurological disorders who still have lower limb sensation and volitional control. A graphical user interface was developed to digitally set stimulation parameters (amplitude, pulse width, and frequency), timing, and intensity during walking. Benchtop testing characterized system delay and power output. System performance was investigated during a single session that consisted of four overground walking conditions in a 15-year-old male with bilateral spastic CP, GMFCS Level III: (1) his current Ankle-Foot Orthosis (AFO); (2) unassisted Exoskeleton; (3) NMES of the vastus lateralis; and (4) NMES of the vastus lateralis and rectus femoris. We hypothesized in this participant with crouch gait that NMES triggered with low latency to knee extensor muscles during stance would have a modest but positive effect on knee extension during stance.

RESULTS

The system delivers four channels of NMES with average delays of 16.5 ± 13.5 ms. Walking results show NMES to the vastus lateralis and rectus femoris during stance immediately improved mean peak knee extension during mid-stance (p = 0.003*) and total knee excursion (p = 0.009*) in the more affected leg. The electrical design, microcontroller software and graphical user interface developed here are included as open source material to facilitate additional research into digitally-controlled surface stimulation ( github.com/NIHFAB/NMES ).

CONCLUSIONS

The custom, digitally-controlled NMES system can reliably trigger electrical stimulation with low latency. Precisely timed delivery of electrical stimulation to the quadriceps is a promising treatment for crouch. Our ultimate goal is to synchronize NMES with robotic knee extension assistance to create a hybrid NMES-exoskeleton device for gait rehabilitation in children with flexed knee gait from CP as well as from other pediatric disorders.

TRIAL REGISTRATION

clinicaltrials.gov, ID: NCT01961557 . Registered 11 October 2013; Last Updated 27 January 2020.

Evaluation of Gait Phase Detection Delay Compensation Strategies to Control a Gyroscope-Controlled Functional Electrical Stimulation System During Walking

Functional electrical stimulation systems are used as neuroprosthetic devices in rehabilitative interventions such as gait training. Stimulator triggers, implemented to control stimulation delivery, range from open- to closed-loop controllers. Finite-state controllers trigger stimulators when specific conditions are met and utilize preset sequences of stimulation. Wearable sensors provide the necessary input to differentiate gait phases during walking and trigger stimulation. However, gait phase detection is associated with inherent system delays. In this study, five stimulator triggers designed to compensate for gait phase detection delays were tested to determine which trigger most accurately delivered stimulation at the desired times of the gait cycle. Motion capture data were collected on seven typically-developing children while walking on an instrumented treadmill. Participants wore one inertial measurement unit on each ankle and gyroscope data were streamed into the gait phase detection algorithm. Five triggers, based on gait phase detection, were used to simulate stimulation to five muscle groups, bilaterally. For each condition, stimulation signals were collected in the motion capture software via analog channels and compared to the desired timing determined by kinematic and kinetic data. Results illustrate that gait phase detection is a viable finite-state control, and appropriate system delay compensations, on average, reduce stimulation delivery delays by 6.7% of the gait cycle.

Correction of Toe-Walking Gait in Children with Spastic Cerebral Palsy by using Electrical Stimulation Therapy

Toe-walking is a very common gait abnormality seen in children with Cerebral Palsy (CP). The present study aims to improvise the toe-walking gait by applying Electrical Stimulation (ES) therapy of the Tricep Surae (TS) muscles. The study was carried out on sixteen children with spastic CP with unilateral toe-walking gait problem, divided into the intervention group that received both ES therapy along with conventional physiotherapy treatment and the control group that received only conventional physiotherapy treatment. Both groups were treated for 60 (30 + 30) minutes per day, for 5 days a week, up to 12 weeks. The gait data were analyzed for spatiotemporal and parameters influencing the walking capacity. The results showed that those children who received the intervention had a significant increase in gait speed by 17.67 % (p = 0.019) and decrease in stride length by 10.25 % (p = 0.037), resulting in improvement of body balance. There was a significant percentage increase in initial contact (heel strike) of 85.71 % (p = 0.000) and flat foot position (loading response) of 49.2 % (p = 0.005), confirming reduction in toe-walking. There was also an increase in the swing power by 39.8 % (p = 0.028) and ground impact by 19.5 % (p = 0.003) suggesting a change in foot contact pattern. The results indicate that ES therapy on TS muscle along with conventional physiotherapy may correct the toe-walking gait in children with spastic hemiplegic CP.

Is functional electrical stimulation an alternative for orthotics in patients with cerebral palsy? A literature review

BACKGROUND

Functional electrical stimulation (FES) is a well-known intervention used during walking to improve walking abilities and correct gait deviations by facilitating the proper muscle group at the appropriate timing in the gait cycle. Our aim was to study the types of surface FES currently used in a cerebral palsy (CP) population and examine the evidence of its ability to improve gait deviations, functional ability and therapeutic effects.

METHODS

A computerized database search was conducted from inception until 6/2016. Included were all clinical trials performing gait analysis of children with CP applying surface FES to any lower leg muscles evaluating the efficiency of the stimulation and any carry-over effect.

RESULTS

Fifteen studies met the inclusion criteria. The most common FES stimulated the dorsi flexors muscles with a positive orthotic effect, improved dorsi flexion during the swing phase and enhanced the foot contact pattern. A smaller 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. No evidence was found to support the use of plantar flexors stimulation in correcting gait deviations. There is scarce evidence of any retention effect.

CONCLUSION

We encourage the clinician to evaluate the use of FES on a case to case basis. Controlled investigations with larger numbers of participants are warranted to determine the orthotic and therapeutic efficacy of FES.

Functional electrical stimulation of the ankle dorsiflexors during walking in spastic cerebral palsy: a systematic review

AIM

To assess the effect of functional electrical stimulation (FES) of ankle dorsiflexors in children and adolescents with spastic cerebral palsy (CP) during walking.

METHOD

A systematic review was performed using the American Academy of Cerebral Palsy and Developmental Medicine methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases were searched for studies applying interventions to patients aged younger than 20 years. Outcomes were classified according to the International Classification of Functioning, Disability and Health (ICF).

RESULTS

Seven hundred and eighty abstracts were found, 35 articles were fully screened, and 14 articles were used for analysis. Only five articles (three studies) were of level I to III evidence. At ICF participation and activity level, there is limited evidence for a decrease in self-reported frequency of toe-drag and falls. At ICF body structure and function level, there is clear evidence (I-III) that FES increased (active) ankle dorsiflexion angle, strength, and improved selective motor control, balance, and gait kinematics, but decreased walking speed. Adverse events include skin irritation, toleration, and acceptation issues.

INTERPRETATION

There are insufficient data supporting functional gain by FES on activity and participation level. However, evidence points towards a role for FES as an alternative to orthoses in children with spastic CP.

WHAT THIS PAPER ADDS

Effects of functional electrical stimulation (FES) point towards a potential role as an alternative to orthoses for patients with spastic cerebral palsy (CP). Some evidence for a decrease in self-reported frequency of toe-drag and falls with the use of FES in spastic CP. Limited evidence for improvements in activity and participation in patients with spastic CP using FES.

Evaluation of Functional Mobility Outcomes Following Electrical Stimulation in Children With Spastic Cerebral Palsy

This study investigated the clinical feasibility of electrical stimulation in enhancing ankle dorsiflexion of the tibialis anterior muscle to improve mobility in children with spastic cerebral palsy. The intervention group received electrical stimulation therapy for 30 minutes and physiotherapy for another 30 minutes for 5 days a week, up to 12 weeks. Gait parameters, Gross Motor Function Measure, Physiological Cost Index, surface electromyogram, and electroencephalogram (EEG) data were recorded pre- and posttreatment. Data were compared with the control group, which received only conventional physiotherapy for 60 minutes. There was an increase in walking speed (17.67%) and Gross Motor Function Measure scores (2.1%) while the Physiological Cost Index value was decreased (19.7%). The analysis of features extracted from the surface electromyogram showed an increase in muscle strength and that of EEG showed increased motor activities. Hence, electrical stimulation combined with conventional physiotherapy improve gait, muscle strength, and motor activities in children with spastic cerebral palsy.

Neuromuscular electrical stimulation-assisted gait increases muscle strength and volume in children with unilateral spastic cerebral palsy

AIM

To determine if neuromuscular electrical stimulation (NMES) applied to the ankle dorsiflexors during gait improves muscle volume and strength in children with unilateral spastic cerebral palsy (CP).

METHOD

Thirty-two children (15 females, 17 males; mean age 10y 8mo, age range 5y 5mo-18y 1mo) with unilateral spastic CP and a Gross Motor Function Classification System of level I or level II were randomly assigned to either the 8-week daily NMES treatment group or control group (usual or conventional treatments). Outcomes at week 8 (post-NMES) and week 14 (carryover) included magnetic resonance imaging for muscle volumes (tibialis anterior, anterior compartment, and gastrocnemius), strength (hand-held dynamometry for isometric dorsiflexion strength and heel raises for functional strength), and clinical measures for lower limb selective motor control.

RESULTS

At week 8, the treatment group demonstrated significantly (p<0.05) increased muscle volumes for tibialis anterior, anterior compartment, medial and lateral gastrocnemius, and dorsiflexion strength not only when compared to their baseline values but also when compared to the control group at week 8. At week 14, both tibialis anterior and lateral gastrocnemius volumes in the treatment group remained significantly increased when compared to their baseline values. However, only lateral gastrocnemius volumes had significantly greater values when compared to the control group at week 14. There were no between group differences in the clinical measures for lower limb selective motor control at week 8 and 14.

INTERPRETATION

Eight weeks of daily NMES-assisted gait increases muscle volume and strength of the stimulated ankle dorsiflexors in children with unilateral spastic CP. These changes are use-dependent and do not carry over after the 8-week treatment period. Gastrocnemius volume also increased post-treatment with carryover at week 14.

The orthotic and therapeutic effects following daily community applied functional electrical stimulation in children with unilateral spastic cerebral palsy: a randomised controlled trial

BACKGROUND

The purpose of this study was to determine the orthotic and therapeutic effects of daily community applied FES to the ankle dorsiflexors in a randomized controlled trial. We hypothesized that children receiving the eight-week FES treatment would demonstrate orthotic and therapeutic effects in gait and spasticity as well as better community mobility and balance skills compared to controls not receiving FES.

METHODS

This randomized controlled trial involved 32 children (mean age 10 yrs 3 mo, SD 3 yrs 3 mo; 15 females, 17 males) with unilateral spastic cerebral palsy and a Gross Motor Function Classification System of I or II randomly assigned to a FES treatment group (n = 16) or control group (n = 16). The treatment group received eight weeks of daily FES (four hours per day, six days per week) and the control group received usual orthotic and therapy treatment. Children were assessed at baseline, post FES treatment (eight weeks) and follow-up (six weeks after post FES treatment). Outcome measures included lower limb gait mechanics, clinical measures of gastrocnemius spasticity and community mobility balance skills.

RESULTS

Participants used the FES for a mean daily use of 6.2 (SD 3.2) hours over the eight-week intervention period. With FES, the treatment group demonstrated a significant (p < 0.05) increase in initial contact ankle angle (mean difference 11.9° 95% CI 6.8° to 17.1°), maximum dorsiflexion ankle angle in swing (mean difference 8.1° 95% CI 1.8° to 14.4°) normalized time in stance (mean difference 0.27 95% CI 0.05 to 0.49) and normalized step length (mean difference 0.06 95% CI 0.003 to 0.126) post treatment compared to the control group. Without FES, the treatment group significantly increased community mobility balance scores at post treatment (mean difference 8.3 units 95% CI 3.2 to 13.4 units) and at follow-up (mean difference 8.9 units 95% CI 3.8 to 13.9 units) compared to the control group. The treatment group also had significantly reduced gastrocnemius spasticity at post treatment (p = 0.038) and at follow-up (dynamic range of motion mean difference 6.9°, 95% CI 0.4° to 13.6°; p = 0.035) compared to the control group.

CONCLUSION

This study documents an orthotic effect with improvement in lower limb mechanics during gait. Therapeutic effects i.e. without FES were observed in clinical measures of gastrocnemius spasticity, community mobility and balance skills in the treatment group at post treatment and follow-up. This study supports the use of FES applied during daily walking activities to improve gait mechanics as well as to address community mobility issues among children with unilateral spastic cerebral palsy.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Register ACTRN12614000949684 . Registered 4 September 2014.

Noninvasive and painless magnetic stimulation of nerves improved brain motor function and mobility in a cerebral palsy case

Motor deficits in cerebral palsy disturb functional independence. This study tested whether noninvasive and painless repetitive peripheral magnetic stimulation could improve motor function in a 7-year-old boy with spastic hemiparetic cerebral palsy. Stimulation was applied over different nerves of the lower limbs for 5 sessions. We measured the concurrent aftereffects of this intervention on ankle motor control, gait (walking velocity, stride length, cadence, cycle duration), and function of brain motor pathways. We observed a decrease of ankle plantar flexors resistance to stretch, an increase of active dorsiflexion range of movement, and improvements of corticospinal control of ankle dorsiflexors. Joint mobility changes were still present 15 days after the end of stimulation, when all gait parameters were also improved. Resistance to stretch was still lower than prestimulation values 45 days after the end of stimulation. This case illustrates the sustained effects of repetitive peripheral magnetic stimulation on brain plasticity, motor function, and gait. It suggests a potential impact for physical rehabilitation in cerebral palsy.

Effect of functional electrical stimulation on activity in children with cerebral palsy: a systematic review

PURPOSE

To determine whether functional electrical stimulation (FES) is effective and whether it is more effective than activity training alone.

METHOD

MEDLINE, CINAHL, EMBASE, Cochrane, Web of Science, and PEDro databases were searched for randomized trials. Studies of randomized trials were included if the participants were children (<18 years old) with spastic cerebral palsy, who underwent a program of FES that involved electrical stimulation during practice of an activity. Measures of activity that best reflected the activity trained were examined.

RESULTS

Five randomized trials were included. Three trials reported statistically significant between-group differences in favor of FES compared with no FES. Two trials reported no statistically significant between-group differences of FES compared with activity training alone.

CONCLUSION

The available evidence suggests that FES is more effective than no FES but that it has a similar effect as activity training alone in cerebral palsy.

Gait detection in children with and without hemiplegia using single-axis wearable gyroscopes

In this work, we develop a novel gait phase detection algorithm based on a hidden Markov model, which uses data from foot-mounted single-axis gyroscopes as input. We explore whether the proposed gait detection algorithm can generate equivalent results as a reference signal provided by force sensitive resistors (FSRs) for typically developing children (TD) and children with hemiplegia (HC). We find that the algorithm faithfully reproduces reference results in terms of high values of sensitivity and specificity with respect to FSR signals. In addition, the algorithm distinguishes between TD and HC and is able to assess the level of gait ability in patients. Finally, we show that the algorithm can be adapted to enable real-time processing with high accuracy. Due to the small, inexpensive nature of gyroscopes utilized in this study and the ease of implementation of the developed algorithm, this work finds application in the on-going development of active orthoses designed for therapy and locomotion in children with gait pathologies.

Muscle plasticity and ankle control after repetitive use of a functional electrical stimulation device for foot drop in cerebral palsy

BACKGROUND/OBJECTIVES

The primary goal was to determine whether repetitive functional electrical stimulation (FES) for unilateral foot drop increases tibialis anterior (TA) muscle size compared with an untreated baseline and the contralateral side in cerebral palsy (CP). Secondary goals were to determine whether positive changes in muscle size and gait, if found, accumulated during the 3 intervals during which participants used the device. FES devices differ from traditional orthoses that often restrict muscle activation and may exacerbate weakness, promote continued dependence on orthoses, or precipitate functional decline.

METHODS

Participants were 14 independent ambulators with inadequate dorsiflexion in swing, with a mean age of 13.1 years, evaluated before and after the 3-month baseline, 1-month device accommodation, 3-month primary intervention, and 3-month follow-up phases. The FES device (WalkAide) stimulated the common fibular nerve to dorsiflex the ankle and evert the foot while monitoring use. TA muscle ultrasound, gait velocity, and ankle kinematic data for barefoot and device conditions are reported.

RESULTS

Ultrasound measures of TA anatomic cross-sectional area and muscle thickness increased in the intervention compared with baseline and with the contralateral side and were maintained at follow-up. Maximum ankle dorsiflexion decreased at baseline but improved or was maintained during the intervention phase with and without the device, respectively. Muscle size gains were preserved at follow-up, but barefoot ankle motion returned to baseline values.

CONCLUSIONS

This FES device produced evidence of use-dependent muscle plasticity in CP. Permanent improvements in voluntary ankle control after repetitive stimulation were not demonstrated.

Tolerability and effectiveness of a neuroprosthesis for the treatment of footdrop in pediatric patients with hemiparetic cerebral palsy

OBJECTIVE

To assess the tolerability and efficacy of a commercially available footdrop neuroprosthesis for treatment of footdrop in children with hemiparetic cerebral palsy.

DESIGN

A prospective, observational pilot study.

SETTING

Marshfield Clinic, Department of Physical Medicine.

PARTICIPANTS

Ten children, ages 7-12 years, with hemiparetic cerebral palsy, who use an ankle foot orthosis (AFO) for correction of footdrop.

METHODS

Children replaced their AFO with a transcutaneous peroneal (fibular) nerve stimulation neuroprosthesis for 3 months.

MAIN OUTCOME MEASUREMENTS

The ability to tolerate fitting and programming of the device, device-recorded wear time, a daily-use diary, satisfaction survey, and secondary measures, including passive range of motion and gait laboratory measurement of gait velocity and ankle kinematics.

RESULTS

All 10 participants (100%) tolerated fitting and programming of the neuroprosthesis and wore the device for 6 weeks. Seven of 10 (70%) wore the device for the entire 3-month study period; 6 of 10 (60%) continued to use the device after study completion. Wear time varied from 2 to 11 hours per day. Tolerability and satisfaction were high; although 6 participants complained of "size" and "bulkiness" of the device, and 2 reported skin irritation. Gait velocity increased in 5 subjects (50%). Seven participants (70%) preferred the neuroprosthesis to their AFO.

CONCLUSION

Analysis of the preliminary evidence suggests that electrical stimulation by a footdrop neuroprosthesis is tolerated well by children and is effective for the treatment of footdrop in children with hemiparetic cerebral palsy. Commercially available neuroprostheses may offer a promising alternative treatment option for children with footdrop.

Acceptability and potential effectiveness of a foot drop stimulator in children and adolescents with cerebral palsy

AIM

Ankle-foot orthoses are the standard of care for foot drop in cerebral palsy (CP), but may overly constrain ankle movement and limit function in those with mild CP. Functional electrical stimulation (FES) may be a less restrictive and more effective alternative, but has rarely been used in CP. The primary objective of this study was to conduct the first trial in CP examining the acceptability and clinical effectiveness of a novel, commercially available device that delivers FES to stimulate ankle dorsiflexion.

METHOD

Twenty-one individuals were enrolled (Gross Motor Function Classification System [GMFCS] levels I and II, mean age 13y 2mo). Gait analyses in FES and non-FES conditions were performed at two walking speeds over a 4 month period of device use. Measures included ankle kinematics and spatiotemporal variables. Differences between conditions were revealed using repeated measures multivariate analyses of variance.

RESULTS

Nineteen individuals (nine females, 10 males; mean age 12y 11mo, range 7y 5mo to 19y 11mo; 11 at GMFCS level I, eight at level II) completed the FES intervention, with all but one choosing to continue using FES beyond that phase. Average daily use was 5.6 hours (SD 2.3). Improved dorsiflexion was observed during swing (mean and peak) and at foot-floor contact, with partial preservation of ankle plantarflexion at toe-off when using the FES at self-selected and fast walking speeds. Gait speed was unchanged.

INTERPRETATION

This FES device was well accepted and effective for foot drop in those with mild gait impairments from CP.

Children with cerebral palsy: a systematic review and meta-analysis on gait and electrical stimulation

Objective: To conduct 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.

Methods: We identified 40 cerebral palsy and electrical stimulation studies, and 17 gait studies qualified for inclusion. Applying enablement classification methods to walking abnormalities created two subgroups: impairment (N = 14) and activity limitations (N = 15). Overall, 238 participants experienced electrical stimulation treatments and 224 served as a no stimulation control group. Calculations followed conventional data extraction and meta-analysis techniques: (a) individual standardized mean differences, (b) summary effect size, (c) I 2heterogeneity test, (d) fail-safe N analysis and (e) moderator variable analyses.

Results: Common outcome measures associated with impairment (n = 3) and activity limitations (n = 6) were submitted to separate random effects models meta-analyses, and revealed significant cumulative effect sizes: (a) impairment = 0.616 (SE = 0.10) and (b) activity limitations = 0.635 (SE = 0.14). I 2indicated low and medium amounts of dispersion, whereas fail-safe analyses revealed high N-values for both disablement categories. Moderator variable analyses further confirmed the positive treatment effects from both functional and neuromuscular stimulation.

Conclusions: The present systematic review and meta-analyses determined medium effect sizes for electrical stimulation on walking impairment and activity limitations of children with cerebral palsy.

The effect of lower limb functional electrical stimulation on gait of children with cerebral palsy

PURPOSE

To examine the effect of lower limb functional electrical stimulation (FES) in children with cerebral palsy.

METHODS

A comprehensive search yielded 37 citations. English articles included in the review applied either surface or percutaneous FES to the lower limb, if subjects were younger than 18 years old, and if the stimulator was removed or off at the time of testing.

RESULTS

Five articles were included in this review, including 3 case reports, 1 single subject, and 1 crossover design. Among the wide range of stimulation protocols, stimulation of the gastrocnemius with or without the tibialis anterior muscle may effect greater gait improvements than stimulating the tibialis anterior muscle alone.

CONCLUSIONS AND RECOMMENDATIONS FOR CLINICAL PRACTICE

Future research differentiating between optimal FES and neuromuscular electrical stimulation protocols as well as more rigorous research designs are needed to provide clinically relevant results.

Functional electrical stimulation to the dorsiflexors and quadriceps in children with cerebral palsy

PURPOSE

To assess the effects of functional electrical stimulation (FES) of the ankle dorsiflexors and quadriceps in children with cerebral palsy.

METHODS

Fourteen children (mean age 8 years) were randomly allocated to a treatment or control group. The treatment group received 2 weeks of neuromuscular electrical stimulation followed by 8 weeks of FES used at home and school. The control group continued with its usual physiotherapy program. Assessment took place at baseline and before and after the treatment period. Both control and treatment groups were fitted with FES for gait analysis at the second and final assessments.

RESULTS

In both groups, FES of the ankle dorsiflexors resulted in a significant (p < 0.01) effect on gait kinematics. However, no long-term treatment effect of using FES for 8 weeks was found.

CONCLUSIONS

FES for selected children with cerebral palsy, receiving adequate support, can be a practical treatment option to improve gait kinematics.