The Rlationship between the Trunk Muscles Activities and Postural Sway during One Leg Standing

Abstract

[Purpose] We investigated the characteristics of electromyographic trunk muscle activities and the relationship between the trunk muscle activities and postural sway during one-leg standing. [Subjects] Ten people (25.1 ± 4.4 years old) participated in this study. [Methods] Electromyographic trunk muscle activities and postural sway were evaluated during one-leg standing and twoleg standing. [Results] Thoracic and lumbar erector spinae and external oblique on the side of the raised leg were activated significantly more higher in one-leg standing than in two-leg standing. Lumbar multifidus and internal oblique on the side of standing leg had a tendency to be activated higher in one-leg standing. After some trunk muscle activities on the side of the raised leg and postural sway correlated significantly. [Conclusion] The results suggest that trunk muscle activities influence the balance ability during one-leg standing.