Gallop-like Gait Pattern In Human Side Stepping

Abstract

Human locomotion is not only forward and backward, we can move sideward as well. Different from forward locomotion, an asymmetric gait pattern was sometimes preferred in side stepping, however, no studies have investigated human sideward locomotion. PURPOSE: To clarify the sideward gait pattern on a treadmill. METHODS: Six male participants were asked to step sideward on a treadmill. The treadmill speed was increased between 1.3 and 6.1 km/h in 0.3 km/h steps of 20s duration each. Participants performed three trials. Participants were instructed to use their preferred gait patterns at all times, and not to cross each foot. No feedback was given on time and speed. Foot contact and take-off timings were visually inspected by using a 300-fps video camera. P1 and P2 were proportions of double support or flight phase (P1: proportion of the time from the trailing foot contact to the leading take-off, P2: proportion of the time from the leading foot contact to the trailing take-off) to the entire stride period. Relative phase was an index of gait symmetry defined as the time from the trailing foot contact to the leading foot contact relative to the entire stride period. RESULTS: A walk-like gait pattern with double support (positive P1 and P2) and symmetric foot contact (relative phase: 0.52±0.03 at 2.2 km/h) was observed in all the participants for the treadmill speed of ∼3.5±0.5km/h (mean±SD). As the treadmill speed increased, five of the six participants showed an asymmetric gallop-like gait pattern. For example, P1 and P2 and relative phase were -0.16±0.03, 0.15±0.01 and 0.35±0.01 at 6.1km/h. On the other hand, over 4.0±0.2km/h the other one showed a symmetric run-like gait pattern. For example, P1 and P2 and relative phase were -0.21±0.01, -0.11±0.01 and 0.46±0.01 at 6.1km/h. CONCLUSIONS: In five out of the six participants, an asymmetric gait pattern was observed and similar to galloping, which is naturally used by quadrupeds at high speeds. Because of the restricted lateral range of motion of the hip and knee joint, the roles of accelerating and decelerating the center of mass might have to be distributed into the trailing and leading limbs, which results in the observed gallop-like asymmetric sideward locomotion.