Patterns of change in propulsion force and late braking force in patients with stroke walking at comfortable and fast speeds

Increased propulsion force (PF) in the paretic limb is associated with improved walking speed in patients with stroke. However, late braking force (LBF), an additional braking force occurring between PF onset and toe-off, is present in a subset of stroke patients. Few studies have investigated the changes in LBF and walking speed in these patients. This study aimed to elucidate the patterns of change in PF and LBF during fast gait in hemiplegics and identify potential compensatory strategies based on the LBF patterns. Data from 100 patients with stroke walking at both comfortable (mean, 0.79 ± 024 m/s) and fast speeds (mean, 1.06 ± 0.35 m/s) were analyzed retrospectively stroke using a 3D motion analyzer. PF was higher during fast-speed walking than that during comfortable-speed walking in all patients, while LBF showed both decreasing and increasing trends during fast-speed walking. In the LBF increasing pattern, a reduction in in-phase coordination of the shank and foot during the pre-swing phase was observed, along with an increase in pelvic hike during fast-speed walking compared to those in the decreasing LBF pattern. Our findings demonstrate that alterations in LBF patterns are associated with gait deviations in patients with stroke at fast speeds.