Foot plantar pressure and centre of pressure trajectory differ between straight and turning steps in infants

Abstract

Plantar pressure has been used to understand loading on infant feet as gait develops. Previous literature focused on straight walking, despite turning accounting for 25% of infant self-directed steps. We aimed to compare centre of pressure and plantar pressure in walking steps in different directions in infants. Twenty-five infants who were walking confidently participated in the study (aged 449 ± 71 days, 96 ± 25 days after first steps). Plantar pressure and video were recorded whilst five steps per infant were combined for three step types: straight, turning inwards and outwards. Centre of pressure trajectory components were compared for path length and velocity. Pedobarographic Statistical Parametric Mapping explored differences in peak plantar pressure for the three step types. Significant differences were identified primarily in the forefoot with higher peak pressures in straight steps. Centre of pressure path was longer in the medial–lateral direction during turning (outward 4.6 ± 2.3, inward 6.8 ± 6.1, straight 3.5 ± 1.2 cm, p < .001). Anterior–posterior velocity was higher in straight steps and medial–lateral velocity highest turning inwards. Centre of pressure and plantar pressures differ between straight and turning steps with greatest differences between straight and turning. Findings may be attributed to walking speed or a function of turning experience and should influence future protocols.