Robotic-assisted locomotor training enhances ankle performance in adults with incomplete spinal cord injury

OBJECTIVE Ankle joint control plays an important role in independent walking. This study investigated the effects of robotic-assisted locomotor training on impaired ankle joint control in individuals with chronic incomplete spinal cord injury. METHODS Sixteen individuals with incomplete spinal cord injury underwent 12 one-h sessions of robotic-assisted locomotor training for 4 weeks, while 16 individuals with incomplete spinal cord injury served as inactive controls. Changes in ankle control measures, torque and co-activation were evaluated during maximal voluntary contractions in dorsi- and plantar-flexion. Changes in walking performance measures using Timed Up and Go (TUG), 10-m walk (10MWT) and 6-min walk (6MWT) tests were evaluated at 2 time points: baseline and after 4 weeks. RESULTS Maximal voluntary contractions torque during both dorsi- and plantar-flexion contractions improved markedly in the robotic-assisted locomotor training group compared with baseline. Furthermore, after the training, co-activation during the dorsi-flexion maximal voluntary contractions decreased in the training group compared with controls. In addition, the training group significantly improved walking mobility (TUG) and speed (10MWT) compared with baseline. Finally, correlation analysis indicated a significant linear relationship between maximal voluntary contraction torques and walking performance measures. CONCLUSION These findings provide evidence that robotic-assisted locomotor training improves ankle joint control, which may translate into enhanced walking performance in individuals with chronic incomplete spinal cord injury.