Analysis of instantaneous energy symmetry index in asymmetrical gait

Human gait or walking pattern is a cyclical movement that involves the coordination of both left limb and right limb to propel the body forward while maintain body balance. Disruption to this natural gait can increase overall energy expenditure and induce additional stress to the joints. Gait asymmetry is one of the common physiological symptoms observed in patients with musculoskeletal and neurological disorder such as stroke. This paper seeks to examine the behavior of instantaneous mechanical energy of the lower limb segments i.e. thigh, shank and foot during stance and swing phases. Analyzing the instantaneous mechanical energy interaction of the lower limbs allows for better understanding on some of mechanisms adopted in asymmetrical gait. This study adopted normalized symmetry index (SI_norm) to identify gait asymmetry. Asymmetrical gait was induced by restricting the knee movement. Greater asymmetry was observed in both kinetic energy and potential energy, implying that the subjects reduced the speed of their lower extremities and lifted their limb segments as the compensation strategy.