Measurement of changes in the physiological cycle-to-cycle variability in gait kinematics using the ELLIS approach holds promise as a new tool for quantitative evaluation of gait adaptability. Adaptability is arguably one of the most crucial factors of gait function. However, functional limitations in adaptability have not been well documented, presumably due to the inability to accurately measure this aspect. For this purpose, we developed a new method to quantify subtle changes in cycle-to-cycle physiological variability in gait kinematics; a technique designated as the entropy of leg-linkage inertial signals (ELLIS) analysis. A previous study (Tochigi et al., JOR 2012) found that the ELLIS outputs in an asymptomatic cohort) became lower with greater age, and that subjects with symptomatic knee osteoarthritis exhibited lower values compared to age-matched asymptomatic subjects. In addition, highly consistent speed-dependent increases in ELLIS outputs (in the asymptomatic subjects) were also documented. This speed-dependency is consistent with the fact that stable walking at a faster pace places higher demands on the neuromuscular control systems. Complex interactions across multiple controlling factors presumably increase perturbations to gait kinematics within the “normal” range (i.e., increase in physiological variability). To advance understanding of the degree of speed dependence, the present study aimed to test whether or not the ELLIS outputs would linearly increase with increase in walking speed.Summary
Introduction
Anatomical variations in hip joint anatomy are associated with both the presence and location of tibiofemoral osteoarthritis (OA). Variations in hip joint anatomy can alter the moment-generating capacity of the hip abductor muscles, possibly leading to changes in the magnitude and direction of ground reaction force and altered loading at the knee. Through analysis of full-limb anteroposterior radiographs, this study explored the hypothesis that knees with lateral and medial knee OA demonstrate hip geometry that differs from that of control knees without OA.Summary
Introduction
