Gait variability of interlimb coordination in high-heeled shoes with detachable base sockets under conditions of sinusoidal speed change.

Background: This study aimed to investigate the effects of wearing high-heeled shoes (HHS) on gait variability of the lower limbs when the treadmill speed was sinusoidally changed.

Methods: A total of 17 young females walked on a treadmill with HHS, HHS with detachable base sockets (HHS-Sockets), and low-heeled shoes (LHS) under sinusoidal speed-changing protocol of 60-s and 30-s periods with an amplitude of ± 0.56 m·s. The time course of the joint elevation angles of the thigh, shank, and foot in one gait cycle can be well approximated like a plane in a triaxial space, so-called intersegmental coordination (IC). Standard deviation of the plane (IC thickness) was considered as the anteroposterior gait variability when the best-fitting plane of the angular covariation was obtained. The lateral gait variability was the coefficient of variance of step width (CV). To examine whether the gait parameters was associated with IC thickness, a sum of the time delay of the stride length and step frequency (TD) against sinusoidal speed change was calculated.

Results: The IC thickness was not different across shoe conditions and periods. The CV was greater in the HHS and HHS-Sockets conditions than in the LHS condition. TD was greater in the HHS condition than in the LHS and HHS-Sockets conditions at both periods; however, it was not correlated with IC thickness.

Significance: Walking with HHS increased lateral gait variability at faster speed-changing situation, but not anteroposterior gait variability. Detachable sockets expanding the base area ten times greater than that of HHS could reduce TD; however, TD could not explain the IC thickness.