The Associations Between Motor Corticospinal Excitability and Neuromechanics of the Paretic Soleus and Tibialis Anterior in People Post-Stroke

The corticospinal drive to the paretic soleus (SOL) and tibialis anterior (TA) is degraded, but whether it changes and is task-dependent remains unclear. We examined the relationships between corticospinal drive and muscle-specific neuromechanics. We collected eight measures of corticospinal drive to SOL and TA in healthy and stroke participants, and muscle-specific neuromechanics during walking and isolated task in stroke participants. We examined the reliability, and the inter-group differences in variance and mean for each corticospinal measure, and the correlations between corticospinal drive and neuromechanics of each muscle in both tasks. Only certain corticospinal measures were simultaneously reliable and had inter-group differences in variance and mean. SOL resting latency was not associated with any neuromechanical measure in either task, whereas TA resting and active latencies were associated with only the ankle angular velocity during walking. In conclusion, TA latencies may strongly indicate an impaired mechanical pattern in the ankle during walking