Lower limb muscle activity underlying temporal gait asymmetry post-stroke

•The asymmetric group exhibited fewer dorsiflexor muscle bursts during swing.•More affected side plantarflexor activity in stance ended early with asymmetry.•Dorsiflexor on/off time of the asymmetric participants differed from controls. Asymmetric walking after stroke is common, detrimental, and difficult to treat, but current knowledge of underlying physiological mechanisms is limited. This study investigated electromyographic (EMG) features of temporal gait asymmetry (TGA). Participants post-stroke with or without TGA and control adults (n = 27, 8, and 9, respectively) performed self-paced overground gait trials. EMG, force plate, and motion capture data were collected. Lower limb muscle activity was compared across groups and sides (more/less affected). Significant group by side interaction effects were found: more affected plantarflexor stance activity ended early (p = .0006) and less affected dorsiflexor on/off time was delayed (p