The Orthotic Effect of Functional Electrical Stimulation on Reactive Stepping for People With Incomplete Spinal Cord Injury

Background Individuals with incomplete spinal cord injury (iSCI) often face challenges initiating reactive steps, leading to an increased risk of falls. Reactive balance training (RBT) can improve balance control; however, it is difficult to participate in RBT without the ability to initiate a reactive step independently. Functional electrical stimulation (FES) has been used to facilitate participation in RBT. FES applied to the common fibular nerve (CFN) following iSCI initiates a flexor withdrawal response, promoting rapid hip and knee flexion and ankle dorsiflexion, potentially aiding the execution of reactive stepping responses. This cross‐sectional study aimed to evaluate the orthotic (i.e., immediate) effect of FES on reactive stepping parameters in participants with chronic, motor iSCI. Methods Sixteen individuals with chronic motor iSCI completed the Lean‐and‐Release test, which elicits reactive stepping through a simulated forward fall. Participants completed 10–20 trials, with FES applied in half at random. The behavioral response (i.e., single‐step, two‐step, ≥ 3‐step, or fall) of each trial was recorded. Temporal parameters (i.e., foot‐off time, swing time, and stepping time) and spatial parameters (i.e., length, height, and width) of the first reactive step were also recorded. Results The proportion of single‐step ( p = 0.31), two‐step ( p = 0.19), ≥ 3‐step ( p = 0.44) and fall ( p = 0.42) behavioral responses did not differ between FES and No‐FES conditions. Additionally, the temporal (foot‐off time ( p = 0.43), swing time ( p = 0.80), and step time ( p = 0.95)) and spatial parameters (length ( p = 0.73), height ( p = 0.70), and width ( p = 0.54)) of the first reactive step did not differ between conditions. Conclusions FES had no orthotic effect on reactive stepping parameters in individuals with chronic motor iSCI.