Purpose: Most literature about the efficacy of tone-reducing orthotics pertains to adults and children with central nervous system (CNS) pathology. There is relatively little mention of using this type of orthotic with adults after spinal cord injury (SCI). Therefore, the purpose of this study was to investigate whether tone-reducing orthotics have an effect on gait including electromyographic (EMG) activity, velocity, step length, time in double-limb support, and SCI-Functional Ambulation Inventory (SCI-FAI) scores for an individual with incomplete SCI and spasticity.
Methods: We used a single case design. The subject was a 25-year-old white male who was 16 months post-injury with a diagnosis of T6 left/T9 right sensory, L3 motor American Spinal Injury Association C incomplete SCI. Five different walking conditions were tested during each of two separate sessions: barefoot, shoes, foot plates, one ankle-foot orthosis (AFO) with a joint, and one with a tone-reducing AFO, and tone-reducing AFOs bilaterally. Surface EMG was used to record electrical activity of four muscle groups bilaterally. Step length, gait velocity, and time in double limb support were calculated for all five walking conditions. Gait parameters were further analyzed with video analysis using the SCI-FAI.
Results: Mean EMG was relatively constant in all muscle groups under all walking conditions with the exception of the gastrocnemius. In this muscle group, EMG activity with the use of tone-reducing orthotics was better modulated than the other conditions. Gait velocity and step length both increased with tone-reducing orthotics, whereas double limb support time decreased, thus improving the corresponding SCI-FAI score accordingly.
Conclusion: The subject showed improvement in the control of his lower extremities while wearing bilateral tone-reducing AFOs as evidenced by an increased step length and gait velocity and a decrease in the amount of time spent in double limb support. Electromyographic data were less conclusive, although activity in the left gastrocnemius muscle group was more erratic under alternative walking conditions when compared to the tone-reducing AFOs.