Symmetry of cortical planning for initiating stepping in sub-acute stroke

OBJECTIVE: This study examined motor planning for stepping when the paretic leg was either stepping or standing (to step with the non-paretic leg), to understand whether difficulty with balance and walking post-stroke could be attributed to poor motor planning. METHODS: Individuals with stroke performed self-initiated stepping. Amplitude and duration of the movement-related cortical potential (MRCP) was measured from Cz. Electromyography (EMG) of biceps femoris (BF) and rectus femoris (RF) were collected. RESULTS: There were no differences between legs in stepping speed, MRCP or EMG parameters. The MRCPs when stepping with the paretic leg and the non-paretic leg were correlated. When the paretic leg was stepping, the MRCP amplitude correlated with MRCP duration, indicating a longer planning time was accompanied by higher cognitive effort. Slow steppers had larger MRCP amplitudes stepping with the paretic leg and longer MRCP durations stepping with the non-paretic leg. CONCLUSIONS: MRCP measures suggest that motor planning for initiating stepping are similar regardless of which limb is stepping. Individuals who stepped slowly had greater MRCP amplitudes and durations for planning. SIGNIFICANCE: Individuals who step slowly may require more time and effort to plan a movement, which may compromise their safety in the community.