Evaluation of muscle fatigue of wheelchair basketball players with spinal cord injury using recurrence quantification analysis of surface EMG.

Wheelchair basketball is the most popular exercise activity among individuals with spinal cord injury (SCI). The purpose of this study was to investigate muscular endurance and fatigue in wheelchair basketball athletes with SCI using surface electromyography (SEMG) and maximal torque values. SEMG characteristics of 10 wheelchair basketball players (WBP) were compared to 13 able-bodied basketball players and 12 sedentary able-bodied subjects. Participants performed sustained isometric elbow flexion at 50% maximal voluntary contraction until exhaustion. Elbow flexion torque and SEMG signals were recorded from three elbow flexor muscles: biceps brachii longus, biceps brachii brevis and brachioradialis. SEMG signals were clustered into 0.5-s epochs with 50% overlap. Root mean square (RMS) and median frequency (MDF) of SEMG signals were calculated for each muscle and epoch as traditional fatigue monitoring. Recurrence quantification analysis was used to extract the percentage of determinism (%DET) of SEMG signals. The slope of the %DET for basketball players and WBP showed slower increase with time than the sedentary able-bodied control group for three different elbow flexor muscles, while no difference was observed for the slope of the %DET between basketball and WBP. This result indicated that the athletes are less fatigable during the task effort than the nonathletes. Normalized MDF slope decay exhibited similar results between the groups as %DET, while the slope of the normalized RMS failed to show any significant differences among the groups (p > 0.05). MDF and %DET could be useful for the evaluation of muscle fatigue in wheelchair basketball training. No conclusions about special training for WBP could be determined.

Functional electrical stimulation of walking: function, exercise and rehabilitation.

For nearly half a century, functional electrical stimulation (FES) has been used to restore walking for people with paralysis and muscle weakness due to stroke and spinal cord injury. The first applications of the technology were intended to permanently replace lost neuromuscular function. Later, FES-assisted walking was found to have therapeutic benefits that include increased muscle strength, cardiovascular fitness and improved gait function that could be maintained after use of FES was terminated. In this review, we examine some of the major FES-assisted walking systems that have been developed for experimental and commercial purposes over the last four and a half decades, including foot drop stimulators, multichannel stimulators and hybrid orthotic systems.

Functional electrical therapy: retraining grasping in spinal cord injury.

OBJECTIVE: To determine the clinical efficacy of functional electrical therapy in the rehabilitation of grasping function for quadriplegics. STUDY DESIGN: Randomized intervention-versus-control trial. SETTING: Rehabilitation hospital for spinal cord injury in Toronto, Canada. METHODS: A total of 21 people with new spinal cord injuries ranging from C3 to C7 were randomly assigned to two groups: Control (N=9) and Intervention (N=12). The intervention was functional electrical therapy, which consisted of repetitive grasping exercises using a neuroprosthesis that applied surface electrical stimulation to the arm to generate and/or assist grasping movements. It was applied by registered Occupational Therapists in a clinical setting. Main outcome measures were: Functional Independence Measure (FIM), Spinal Cord Independence Measure (SCIM), and the Rehabilitation Engineering Laboratory Hand Function Test. Consumer perceptions of functional electrical therapy were assessed via qualitative interviews. RESULTS: Differences between the Control and Intervention groups could be observed although they are not significant due to an insufficient number of participants. Consumer perceptions were positive, including improved Activities of Daily Living and self-satisfaction. CONCLUSION: Functional electrical therapy has the potential to be an effective treatment modality to restore grasping function in quadriplegia. It can be implemented by occupational therapists in a clinical setting. Further research is required to establish suitable indications for participant selection. In addition, a larger number of participants is needed to demonstrate statistical significance of the Functional Electrical Therapy.

Gait training regimen for incomplete spinal cord injury using functional electrical stimulation.

STUDY DESIGN: Case series, and repeated assessments of the same individuals. OBJECTIVE: To demonstrate the feasibility and efficacy of a multiweek intervention on walking function in people with chronic, incomplete spinal cord injuries. SETTING: Rehabilitation hospital for spinal cord injury (SCI) in Toronto, Canada. METHODS: A convenience sample of five subjects with chronic, incomplete SCI trained for 12-18 weeks using a new multichannel neuroprosthesis for walking. The following outcome measures were recorded throughout the training period: walking speed, step frequency and average stride length based on a 2-min walk test. Also identified were which walking aids and orthoses subjects preferred to use, and whether they employed a step-to or step-through gait strategy. Follow-up measurements of three subjects were made up to 10 weeks after treatment. RESULTS: All subjects demonstrated significant improvements in walking function over the training period. Four of the subjects achieved significantly increased walking speeds, which were due to increases in both stride length and step frequency. The fifth subject experienced a significant reduction in preferred assistive devices. Follow-up measurements revealed that two subjects walked slightly slower several weeks after treatment, but they still walked significantly faster than at the start of treatment. CONCLUSION: The gait training regimen was effective for improving voluntary walking function in a population for whom significant functional changes are not expected. This application of functional electrical therapy is viable for rehabilitation of gait in incomplete SCI.