Inter-limb centre of pressure symmetry during gait among stroke survivors

Abstract

The purpose of the present study was to describe the spatial-temporal parameters of the centre of pressure (COP) trajectory during the single-support phase of gait among stroke survivors and relate these parameters to the severity of sensorimotor impairment. Fifty-seven participants were asked to walk at their preferred and fast speed over a pressure sensitive mat. Outcome measures included anterior-posterior (AP) COP displacement, AP-COP velocity, medial-lateral (ML) COP variability and foot region COP time. The results demonstrated an asymmetrical AP-COP displacement in favour of the non-paretic limb for the majority of participants. The inter-limb difference scores for AP-COP displacement and AP-COP velocity were related to the severity of sensorimotor impairment and greater among gait aid users. ML-COP variability was greater under the non-paretic limb, possibly suggesting difficulty with paretic limb swing phase. Reduced or absent forefoot COP time suggests difficulty with forward progression and modified foot function during push-off. The inter-limb difference in COP parameters highlights the asymmetrical nature of post-stroke gait and the challenge of maintaining single limb support. We view this information as potentially important to clinicians as an outcome measure for gait rehabilitation.

Neuromuscular control of curved walking in people with stroke: Case report

“…In comparison to straight paths, the COP trajectory is modulated during curved walking, as seen by the reduction in AP displacement, lateral shift in position, and greater ML variability. Similar to a previous study, S1 demonstrated poor forward progression on the paretic side and a greater difference between limbs for AP-COP displacement than S2, likely due to a greater severity in lower-limb sensorimotor control [27]. The difference between limbs for AP-COP displacement may be related to challenges in controlling stability during forward progression over the paretic limb.…”

“…Research on measuring the COP trajectory to understand neuromuscular control during walking in the stroke population has mainly focused on straight walking and gait initiation [27,33]. In comparison to straight paths, the COP trajectory is modulated during curved walking, as seen by the reduction in AP displacement, lateral shift in position, and greater ML variability.…”

“…Our participants walked at their comfortable pace for each condition, which reduced as the path curvature increased. Slower walking speeds have been demonstrated to produce a shorter AP-COP displacement and smaller ML-COP variability in the stroke population [27]. Future controlled studies will require a matched speed across conditions to discern the effects of walking speed and curve difficulty.…”

“…Examining the COP trajectory may provide information on the capacity to turn or walk along curved paths. Individuals with stroke demonstrate less ML variability and shorter anterior-posterior (AP) displacement in the COP trajectory under the paretic foot than the nonparetic foot during straight walking [27]. These findings suggest poor control of ML stability and forward progression, which coincides with a reduced single support time on the paretic side [27].…”

“…Individuals with stroke demonstrate less ML variability and shorter anterior-posterior (AP) displacement in the COP trajectory under the paretic foot than the nonparetic foot during straight walking [27]. These findings suggest poor control of ML stability and forward progression, which coincides with a reduced single support time on the paretic side [27]. In addition, this may lead to difficulty adapting the gait pattern to match the greater demands required of curved walking.…”