Influence of high-intensity sustained exercise by the lower limbs on gait properties

An abnormal gait mainly comes from structural changes in the musculoskeletal system and degeneration of the nervous system with age. If a temporary decrease of leg muscle function induced by muscle fatigue produces a similar abnormal gait, useful findings regarding the influence of a decrease in leg muscle function on falling by the elderly during gait may be obtained. This study examined the influence of a temporary decrease in leg muscle function induced by high-intensity sustained exercise on gait properties. Fifteen young male adults performed an eccentric barbell squat exercise for 10 repetitions per 10 sets with 2 min rest per set to produce the decrease in leg muscle function. The barbell load was 80% of the subject's concentric one-repetition maximum (1RM). The following parameters were measured during walking, before and after exercise: stance time, double support time, single support time, step length, base width, gait and toe angles, gait speed, and cadence. Single support time, step length, base width, gait and toe angles, and gait speed, in addition to leg strength and vertical jump performance significantly changed after exercise. When the leg muscle function decreased, the gait became unstable and slow, and subjects kept their body stable during walking by spreading both feet outward, enlarging the base width, and shortening step length and the duration of supporting the body with one leg. Although gait properties induced by a temporary leg muscle function decrease are similar to those of the elderly, it was judged that the gait change would not increase the risk of falling. © Springer-Verlag Italia 2008.