Clinical Audit of 5 Years Provision of the Odstock Dropped Foot Stimulator

The Odstock dropped foot stimulator (ODFS) is a foot switch controlled single channel neuromuscular stimulator for correction of dropped foot. Following a randomized controlled trial, the ODFS was recommended for use in the United Kingdom's National Health Service and a clinical service established. The patient performance was assessed by measurement of walking speed over 10 m, physiological cost index (PCI), and by questionnaire. After 4.5 months stroke patients (n = 111) showed a mean increase in walking speed of 27% and reduction in PCI of 31% with stimulation and changes of 14% and 19%, respectively, unassisted. Multiple sclerosis patients (n = 21) gained similar orthotic benefit but no carry over. The principal reason cited for using the equipment was that it reduced the effort of walking. The principal reasons identified for discontinuing were an improvement in mobility, electrode positioning difficulties, and deteriorating mobility. A comprehensive clinical follow-up service is essential to achieve the maximum continuing benefit from FES based orthosis.     

Functional electrical stimulation for a dropped foot

The purpose of this collective review is to study the techniques, usage, methods, and clinical results of functional electrical stimulation applied to the peroneal nerve in the treatment of dropped foot. When stimulation is applied through surface electrodes, clinical reports have documented the therapeutic and orthotic benefits of functional electrical stimulation. Clinical trials are now being undertaken in which implantable electrodes are being used to stimulate the peroneal nerve in patients with dropped foot.     

Experience of Clinical Use of the Odstock Dropped Foot Stimulator

Abstract: The Odstock dropped foot stimulator (ODFS) is a simple functional electrical stimulation (FES) device for the correction of dropped foot. Improved reliability, fine control of stimulation parameters, and careful application and follow-up have led to 86% compliance. Data on 56 patients (50 patients with hemiplegia, 5 patients with multiple sclerosis, and 1 patient with spinal cord injury) who have used the system for between 6 and 18 months are presented and show a statistically significant increase in walking speed with the stimulator at 3 months of 14% (p < 0.001); decreased effort of walking, measured as physiological cost index (PCI), of 37% (p < 0.001); and statistically significant improvement in functional mobility tests and questionnaires. No statistically significant carryover was seen although 3 patients had sufficient improvement in active ankle control and gait parameters to no longer need the stimulator. Six patients who used the stimulator all day every day had a problem with skin irritation, which we have not yet been able to solve. Two patients discontinued use after experiencing increased spasticity in the calf.     

A pilot study to investigate the combined use of botulinum neurotoxin type a and functional electrical stimulation, with physiotherapy, in the treatment of spastic dropped foot in subacute stroke

The objective was to inform sample size calculations for a full randomized controlled trial (RCT). The design included an RCT pilot trial with a 16 week study period, including a 4 week baseline phase. The subjects were adults within 1 year of first stroke, ambulant with a spastic dropped foot. Twenty-one participants were recruited from the stroke services of 4 centers. For intervention all participants received physiotherapy; the treatment group also received botulinum neurotoxin Type A (BoNTA) intramuscular injections to triceps surae (800 U Dysport) and functional electrical stimulation (FES) of the common peroneal nerve to assist walking. The main outcome measure was walking speed. The result was a significant upward trend in median walking speed for both the control (p = 0.02) and treatment groups (nonstimulated p = 0.004, stimulated p = 0.042). Trend lines were different in location (p = 0.04 and p = 0.009, respectively). In conclusion, there is evidence of an additional, beneficial effect of BoNTA and FES. Sufficient information has been gained on the variability of the primary outcome measure to inform sample size calculations for a full RCT to quantify the treatment effect with precision.     

A clinically meaningful training effect in walking speed using functional electrical stimulation for motor-incomplete spinal cord injury

Context/Objective: The study aimed to investigate the presence of a training effect for rehabilitation of walking function in motor-incomplete spinal cord injury (SCI) through daily use of functional electrical stimulation (FES).

Setting: A specialist FES outpatient centre.

Participants: Thirty-five participants (mean age 53, SD 15, range 18-80; mean years since diagnosis 9, range 5 months - 39 years) with drop foot and motor-incomplete SCI (T12 or higher, ASIA Impairment Scale C and D) able to ambulate 10 metres with the use of a walking stick or frame.

Interventions: FES of the peroneal nerve, glutei and hamstrings as clinically indicated over six months in the community.

Outcome Measures: The data was analysed for a training effect (difference between unassisted ten metre walking speed at baseline and after six months) and orthotic effects (difference between walking speed with and without FES) initially on day one and after six months. The data was further analysed for a minimum clinically important difference (MCID) (>0.06 m/s).

Results: A clinically meaningful, significant change was observed for initial orthotic effect (0.13m/s, CI: 0.04-0.17, P?=?0.013), total orthotic effect (0.11m/s, CI: 0.04-0.18, P?=?0.017) and training effect (0.09m/s, CI: 0.02-0.16, P?=?0.025).

Conclusion: The results suggest that daily independent use of FES may produce clinically meaningful changes in walking speed which are significant for motor-incomplete SCI. Further research exploring the mechanism for the presence of a training effect may be beneficial in targeting therapies for future rehabilitation.     

The Case Western Reserve University hybrid gait orthosis

Six individuals with paraplegia and injury levels from C-1 through T-12 participated in a study to evaluate the functional capabilities of a hybrid gait orthotic system. Subjects learned to use a custom-built reciprocal gait orthosis without stimulation and with electrical stimulation activating between 4 and 16 muscles. Outcomes were scored with standard physical therapy measures including the Tinetti test, a timed get up and go, Borg rating of perceived exertion, and the Functional Index Measure (FIM). Subjects have successfully accomplished sit to stand, stand to sit, and walking maneuvers measured for time, speed, and distance. Metabolic consumption was measured for walking in the light work region of 5.1 to 6.5 metabolic equivalents (METs) 1 MET = 3.5 ml of O2/kg/min with hybrid gait orthosis. Perceived exertion as measured with the Borg scale indicated that use of the bracing system with functional electrical stimulation was "easier" than without stimulation. Subjects using a hybrid system were able to walk up to 350 m at average speeds of 0.25 m/s. Walking speeds for 30- and 50-meter distances reached 0.45 m/s. Additionally, walking distances with stimulation were 2 times greater than those of non-stimulated reciprocal gait. FIM scores indicated that system users would become slightly more independent in mobility. Results were used to determine the most useful brace modifications for the next generation of Case Western Reserve University hybrid gait orthoses to allow an expanded function that will include stair climbing and side stepping.     

The Case Western Reserve University Hybrid Gait Orthosis

Abstract

Six individuals with paraplegia and injury levels from C-1 through T-12 participated in a study to evaluate the functional capabilities of a hybrid gait orthotic system. Subjects learned to use a custom-built reciprocal gait orthosis without stimulation and with electrical stimulation activating between 4 and 16 muscles. Outcomes were scored with standard physical therapy measures including the Tinetti test, a timed get up and go, Borg rating of perceived exertion, and the Functional Index Measure (FIM). Subjects have successfully accomplished sit to stand, stand to sit, and walking maneuvers measured for time, speed, and distance. Metabolic consumption was measured for walking in the light work region of 5.1 to 6.5 metabolic equivalents (METs) 1 MET= 3.5 ml of 02/kg/min with hybrid gait orthosis. Perceived exertion as measured with the Borg scale indicated that use of the bracing system with functional electrical stimulation was “easier” than without stimulation. Subjects using a hybrid system were able to walk up to 350 m at average speeds of 0.25 m/s. Walking speeds for 30- and 50-meter distances reached 0.45 m/s. Additionally, walking distances with stimulation were 2 times greater than those of non-stimulated reciprocal gait. FIM scores indicated that system users would become slightly more independent in mobility. Results were used to determine the most useful brace modifications for the next generation of Case Western Reserve University hybrid gait orthoses to allow an expanded function that will include stair climbing and side stepping.     

Use of Functional Electrical Stimulation in the Lower Extremities of Incomplete Spinal Cord Injured Patients

After a program of therapeutic electrical stimulation, 3 groups of incomplete spinal cord injured (SCI) patients were identified, those in whom an improvement of both voluntary and stimulated muscle force was observed, those with an increase in stimulation response only, and patients in whom no effect of electrical stimulation training could be recorded. As it is difficult to predict the outcome of the electrical stimulation rehabilitation process, a diagnostic procedure was developed to predict soon after accidents which incomplete SCI patients are candidates for permanent use of a functional electrical stimulation (FES) orthotic aid. The candidates for chronic use of FES are patients with weak ankle dorsiflexors and sufficiently strong knee extensors. These patients are equipped with a single channel peroneal stimulator augmenting dorsiflexion and knee and hip flexion in a total lower limb flexion response. By applying FES to the ankle plantar flexors, the swing phase of walking can be significantly shortened and faster walking obtained.     

Demand for and Use of Functional Electrical Stimulation Systems and Conventional Orthoses in the Spinal Lesioned Community of the UK

The use of and demand for functional electrical stimulation (FES) systems and conventional orthoses in the spinal cord lesioned population was assessed. The assessment was conducted by a postal survey of the members of the spinal injury associations in the U.K. Out of all the respondents, only 2% had used an FES system for walking. In comparison, 13% had used some kind of orthosis. Of the small numbers who had used an FES system for walking, more than half had no functional walking abilities. The majority of orthosis users had some independent walking ability. The demand for walking improvements was high among the respondents although this was not matched by the demand for improved orthotic solutions. In conclusion, it would appear that there is a need for simple FES systems offering walking improvement to the incomplete spinal cord lesioned (SCI) subject.     

Functional electrical stimulation for foot drop in the upper motor neuron syndrome: does it affect 3D foot kinematics during the stance phase of walking?

BackgroundFoot-drop is a common impairment in individuals with upper motor neuron syndrome. It may cause walking instability, and greater risk of tripping and falling. Ankle–foot orthoses are the standard of care for foot-drop, but may constrain ankle movement and limit function. Functional electrical stimulation (FES) was shown to be a less restrictive and effective alternative. Previous studies have addressed the improvement of ankle dorsiflexion during swing and initial contact. However, the foot motion is 3-dimensional and if the stimulation of m. peroneus longus and m. tibialis anterior is not well balanced, excessive eversion or inversion of the foot can occur respectively. Therefore, the objective is to show the effect of FES on foot motion during walking.MethodsSixteen patients with an upper motor neuron syndrome, with a mean age of 15.7 (SD=8.7) years, GMFCS I and II and foot-drop were included. Gait analyses in FES and non-FES conditions were performed at preferred walking speed using the Oxford Foot Model. Differences between conditions were revealed using a t-test.ResultsUse of FES significantly increased peak dorsiflexion in swing phase during walking by 4.7̊ (SD=6.0̊). Eversion of the rearfoot and abduction of the forefoot significantly increased during initial ground contact by 3.7̊ (SD=4.9̊) and 1.9̊ (SD=2.2̊) respectively. This translates to a significant eversion and abduction of 1.4̊ (SD=2.7̊) and 1.3̊ (SD=2.1̊) during stance phase of walking.ConclusionsFES aiming for improved dorsiflexion in swing, increases hindfoot eversion and forefoot abduction that translates into initial contact and persists, although to a lesser extent, during stance phase of walking. The consistent increase in rearfoot eversion may be due to the strategy of choosing higher stimulation intensity and accept exaggerated eversion. While this strategy provides a certain amount of safety and functionality, it affects foot kinematics during stance phase of walking. This can be advantageous for a clubfoot deformity and may have implications for their therapy but deteriorates an existing flatfoot deformity.     

Further Development of Hybrid Functional Electrical Stimulation Orthoses

Abstract: In this study two aspects of hybrid functional electrical stimulation (FES) orthoses were investigated: joint motion constraints and FES control strategies. First, the effects of joint motion constraints on the gait of normal subjects were investigated using modern motion analysis systems, including electromyogram (EMG) and heart rate measurements. An orthosis was developed to impose joint motion constraints; the knee and ankle could be fixed or free, and the hip joint could rotate independently or coupled, according to a preset flexion-extension coupling ratio (FECR). Compared with a 1:1 hip FECR, a 2:1 hip FECR was associated with a reduced energy cost and increased speed and step length. The knee flexion during swing significantly reduced energy cost and increased walking speed. Ankle plantar flexion reduced the knee flexing moment during the early stance phase. Second, trials on 3 paraplegic subjects were conducted to implement some of these findings. It appeared that the 2:1 FECR encouraged hip flexion and made leg swing easier. A simple FES strategy increased walking speed and step length and reduced crutch force impulse using fixed orthotic joints.     

The effect of walking speed on peak plantar pressure

BACKGROUND: Plantar pressure measurements often are used as a tool to evaluate pathologic gait. Previous studies, often done at self-selected walking speeds, have used peak plantar pressure to try to predict ulcer formation, compare surgical outcomes, and evaluate orthotic device efficacy. However, the relationship between walking speed and plantar pressures at specific plantar regions has not been clearly defined. METHODS: Twenty normal subjects walked on a treadmill at six speeds (0.75 to 2.00 m/s). In-shoe peak plantar pressure was measured at five plantar regions and compared across the range of speeds. RESULTS: Walking speed affected peak plantar pressure differently at the five examined plantar regions. The hallux and heel regions had the highest pressures, which increased linearly with faster speeds. The central and medial forefoot pressures initially increased but plateaued at the faster speeds, while the lateral forefoot had the lowest overall peak pressures, which decreased at the faster walking speeds. Therefore, significant quadratic effects were found at the forefoot. Best-fit regression equations defined distinct pressure-speed relationships at each plantar region (p < 0.0001). CONCLUSION: The effect of walking speed on peak plantar pressure varied with plantar region. To achieve more robust peak plantar pressure measurements, walking speed should be controlled. Determining the normal plantar function across a range of speeds can aid in the development of shoes and foot orthoses. The pressure-speed relationships presented in this study can be used as a comparative tool for evaluating the efficacy of clinical interventions for pressure reduction, especially when walking speed changes may confound the outcomes.     

The effect of a subject-specific amount of lateral wedge on knee mechanics in patients with medial knee osteoarthritis.

We examined if a subject-specific amount of lateral wedge added to a foot orthosis could alter knee mechanics to potentially reduce the progression of knee osteoarthritis in patients with medial knee osteoarthritis. Twenty individuals with medial knee osteoarthritis (>/=2 Kellgren Lawrence grade) were prescribed a custom laterally wedged foot orthotic device. The prescribed wedge amount was the minimal wedge amount that provided the maximum amount of pain reduction during a lateral step-down test. Following an accommodation period, all subjects returned to the laboratory for a gait analysis. Knee mechanics were collected as the subjects walked at an intentional walking speed. Walking in the laterally wedged orthotic device significantly reduced the peak adduction moment during early stance (p < 0.01) compared to the nonwedged device. Similarly, the wedged orthotic device significantly reduced the knee adduction excursion from heel strike to peak adduction (p < 0.01) compared to the nonwedged device. No differences in the peak adduction moment during propulsion or peak adduction during stance were observed between the orthotic conditions. A subject-specific laterally wedged orthotic device was able to reduce the peak knee adduction moment during early stance, which is thought to be associated with the progression of knee osteoarthritis. Previous studies on this device have reported issues associated with foot discomfort when using wedge amounts >7 degrees; however, no such issues were reported in this study. Therefore, providing a custom laterally wedged orthotic device may potentially increase compliance while still potentially reducing disease progression.     

Energy expenditure during walking with weight-bearing control (WBC) orthosis in thoracic level of paraplegic patients

STUDY DESIGN: Comparative study of the effectiveness of walking exercise with a newly developed gait orthosis, the weight-bearing control (WBC) orthosis, for thoracic level of paraplegic patients. OBJECTIVES: To test its feasibility as a rehabilitation alternative for paraplegic patients, the energy consumption and cost during walking with WBC were calculated and compared with the values of conventional orthoses given in previous reports. SETTING: National Rehabilitation Center for the Disabled, Japan. METHODS: Four paraplegic patients with traumatic spinal cord injuries ranging from T8 to T12 participated. Experiments were conducted after 3 months of the orthotic gait training with WBC. The cardiorespiratory parameters were continuously measured at rest and during walking with a telemetric device. The steady-state value of the oxygen uptake (V(O2)), heart rate (HR), the energy consumption (J/kg/s) and energy cost (J/kg/m) were calculated. RESULTS: The average walking speed was 19.0 +/- 2.58 m/min. The steady-state value of the V(O2) and HR were 16.08 +/- 1.93 ml/kg and 147.3 +/- 10.94 b/min, respectively. The energy cost during orthotic walking tended to be better than the values of conventional orthoses, whereas the energy consumption was almost similar. CONCLUSION: WBC enables thoracic level of paraplegic patients to walk at relatively higher speed than conventional orthoses under similar energy expenditure. The special devices equipped with WBC are therefore considered to lead to improvement of the energy cost of walking. The physical intensity presumed by cardiorespiratory responses during walking with WBC is suited to promote their aerobic capacity. Therefore, it is concluded that the WBC orthosis could be an effective alternative in rehabilitation for thoracic level of paraplegic patients.     

Impact of an implanted neuroprosthesis on community ambulation in incomplete SCI

Objective: Test the effect of a multi-joint control with implanted electrical stimulation on walking after spinal cord injury (SCI).

Design: Single subject research design with repeated measures.

Setting: Hospital-based biomechanics laboratory and user assessment of community use.

Participants: Female with C6 AIS C SCI 30 years post injury.

Interventions: Lower extremity muscle activation with an implanted pulse generator and gait training.

Outcome Measures: Walking speed, maximum distance, oxygen consumption, upper extremity (UE) forces, kinematics and self-assessment of technology.

Results: Short distance walking speed at one-year follow up with or without stimulation was not significantly different from baseline. However, average walking speed was significantly faster (0.22?m/s) with stimulation over longer distances than volitional walking (0.12?m/s). In addition, there was a 413% increase in walking distance from 95?m volitionally to 488?m with stimulation while oxygen consumption and maximum upper extremity forces decreased by 22 and 16%, respectively. Stimulation also produced significant (P?≤?0.001) improvements in peak hip and knee flexion, ankle angle at foot off and at mid-swing.

Conclusion: An implanted neuroprosthesis enabled a subject with incomplete SCI to walk longer distances with improved hip and knee flexion and ankle dorsiflexion resulting in decreased oxygen consumption and UE support. Further research is required to determine the robustness, generalizability and functional implications of implanted neuroprostheses for community ambulation after incomplete SCI.     

Therapeutic electrical stimulation of the lower limb by epimysial electrodes

The problem of inadequate hip stability prevents many patients with head trauma, stroke, or spinal injury from balancing on one limb in order to take a step. There is no adequate orthotic substitute for hip instability, and electrical stimulation with surface electrodes cannot effectively activate the deep hip muscles. This report describes a clinical program in which electrical stimulation via surgically placed electrodes is combined with routine tendon lengthening and transfers and physical therapy. The electrodes are fixed to the epimysium and the leads directed subcutaneously to exit the skin at a common site for attachment to a commercially available stimulator. Preliminary results indicate that functional muscle contractions of the deep hip muscles can be obtained with epimysial electrodes and that stimulation can be used to augment walking ability. The results demonstrate the safety and effectiveness of percutaneous electrical stimulation and contribute to the development of a practical, implanted stimulation system for patients who do not regain hip instability after an upper motor neuron lesion.     

Electrophysical therapy for managing diabetic foot ulcers: a systematic review

To systematically assess published reports on the efficacy of electrophysical therapy in the treatment of diabetic foot ulcers, including electrical stimulation, low‐level laser therapy, therapeutic ultrasound and electromagnetic therapy. Databases searched included MEDLINE, CINAHL, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1966 to 2011. Studies reviewed included only randomised controlled trials (RCTs) on treatment with electrophysical modalities compared with sham, conventional treatment or other electrophysical modalities. Information extracted were objective measures of healing and data useful for the calculation of effect size. Eight RCTs were eventually included in the critical appraisal, with a combined total of 325 participants. Five studies were conducted on electrical stimulation, two on phototherapy and one on ultrasound. All studies reported that the experimental group was significantly more favourable than the control or sham group. The pooled estimate of the number of healed ulcers of the three studies on electrical stimulation compared to the control or sham electrical stimulation showed statistical significance [mean difference of 2·8 (95% CI = 1·5–5·5, P = 0·002] in favour of electrical stimulation. The results indicated potential benefit of using electrophysical therapy for managing diabetic foot ulcers. However, due to the small number of trials ever conducted, the possibility of any harmful effects cannot be ruled out, and high‐quality trials with larger sample sizes are warranted.     

Neuromuscular electrical stimulation and dynamic bracing as a treatment for upper-extremity spasticity in children with cerebral palsy.

We have investigated a therapeutic regimen using neuromuscular electrical stimulation (NMES) and dynamic bracing to assess their effectiveness in reducing upper-extremity spasticity in children with cerebral palsy. Nineteen patients between 4 and 21 years of age with documented diagnoses of spastic cerebral palsy were treated. The patients included in the study followed a regimen of two 30-minute sessions of NMES of the antagonist extensors combined with dynamic orthotic traction during the day. A static brace was used at night. Spasticity of the wrist and fingers was assessed periodically using the Zancolli classification. Treatment ranged from 3 to 43 months. After treatment with electrical stimulation and dynamic bracing, all the patients moved up 1 to 3 levels in the Zancolli classification and showed a marked improvement in upper-extremity function. These results show that combining NMES and dynamic orthotic traction dramatically decreases spasticity of the upper extremity in young patients with cerebral palsy.     

Extracorporeal shockwave therapy in the management of plantar fasciitis: A randomized controlled trial

BackgroundThis study aimed at estimating the extent to which a combination therapy of extracorporeal shockwave therapy (ESWT) with usual care (exercise and orthotic support) improve functional ability in the patient with plantar fasciitis when compared to usual care alone.MethodsParticipants with plantar fasciitis were randomly allocated into two groups: ESWT (n = 23), and control (n = 21). All participants received home exercise program with orthotic support. In addition, ESWT group received 2000 shock waves with 0.02 mJ/mm² for three sessions. Functional outcomes were measured by function subscale of American orthopedic foot and ankle society (AOFAS-F) score and 12 minutes walking test including walking speed, cadence. The scores were recorded at baseline, third week and third month after the treatment. Analysis was performed using repeated measures ANOVA, and an intention to treat approach using multiple imputations.ResultsResults showed that there was a significant improvement in AOFAS-F total score and walking speed over three months in both groups (p < 0.001, p = 0.04 respectively); improvements in AOFAS-F were particularly in activity limitation (p = 0.001), walking distance (p = 0.02) and walking surface (p = 0.02). Groups were comparable with each other for both walking speed and AOFAS-F in any assessment time (p > 0.05). However, groups performed differently in cadence where there was an increase in cadence in ESWT group whereas a decline in control at the third month (p = 0.07).ConclusionThe results revealed that ESWT did not have an additive benefit over usual care to improve foot function and walking performance in patient with plantar fasciitis over three months post-treatment.