Effect of lower limb preference on variability of centre of pressure movement during gait

Abstract

Background: Centre of pressure (COP) movement variability, as an example of 'end-point' variability (stability), may be one of the indicators that can assess the functional gait asymmetry caused by foot preference in relation to fall risk. Objective: The aim of this study was to investigate the possible differences in COP movement variability during the stance phase of gait caused by both aging and lower limb preference. Methods: Two groups of females participated in this study: Younger (n = 25, age 22.2 ± 1.8 years) and Middle-aged (n = 25, age 56.6 ± 4.9 years). COP movement and ground reaction forces during gait at self-selected speed were recorded using two force platforms. The standard deviations of the medial-lateral and anterior-posterior COP displacements in four subphases: loading response (LR), midstance (MSt), terminal stance (TSt) and pre-swing (PSw) were assessed. Results: The observed variables indicated significantly higher mean values in almost all cases in subphases LR and PSw in comparison with MSt and TSt. When comparing preferred and non-preferred limb, the preferred limb showed greater variability in medial-lateral direction during LR and less variability in anterior-posterior direction during PSw. In the Younger group, greater variability was found on preferred limb in anterior-posterior direction during LR. When assessing age-related differences all significant cases showed higher variability in the Middle-aged group. Conclusions: The results suggest that COP movement variability is less on the non-preferred limb during weight acceptance and on the preferred limb during propulsion.

Keywords

• fall risk
• ground reaction force
• limb dominance
• limb preference
• stability
• walking