Background and Purpose:

Asymmetry during walking may be explained by impaired interlimb coordination. We examined these associations:(1) propulsive symmetry with interlimb coordination during walking,(2) work symmetry with interlimb coordination during pedaling, and (3) work symmetry and interlimb coordination with clinical impairment.

Methods:

Nineteen individuals with chronic stroke and 15 controls performed bilateral, lower limb pedaling with a conventional device and a device with a bisected crank and upstroke assistance. Individuals with stroke walked on a split-belt treadmill. Measures of symmetry (% Propulsion walk,% Work ped) and interlimb phase coordination index (PCI walk, PCI ped) were computed. Clinical evaluations were the lower extremity Fugl-Meyer (FMLE) and walking speed. Associations were assessed with Spearman's rank correlations.

Results:

Participants with stroke displayed asymmetry and impaired interlimb coordination compared with controls (P≤ 0.001). There were significant correlations between asymmetry and impaired interlimb coordination (walking: R 2= 0.79, P< 0.001; pedaling: R 2= 0.62, P< 0.001) and between analogous measures across tasks (% Work ped,% Propulsion walk: R 2= 0.41, P= 0.01; PCI ped, PCI walk: R 2= 0.52, P= 0.003). Regardless of task, asymmetry and interlimb coordination were correlated with FMLE (R 2≥ 0.48, P≤ 0.004) but not walking speed. There was larger within group variation for% Propulsion walk than% Work ped (Z= 2.6, P= 0.005) and for PCI ped than PCI walk (Z= 3.6, P= 0.003).

Discussion and Conclusions:

Pedaling may provide useful insights about walking, and impaired interlimb coordination may contribute to asymmetry in walking. Pedaling and walking provide distinct insights into stroke-related impairments, related to whether the task allows compensation (walking> pedaling) or compels paretic limb use (pedaling> walking). Pedaling a device with a bisected crank shaft may have therapeutic value.