Effects of an Unstable Dual Foot Support on the Trunk Flexion Angle and RF, L4-ES, EO Muscle Activities during Computer Work

Abstract

[Purpose] The purpose of this study was to show the effects of an unstable dual foot support on the trunk flexion angle and rectus femoris (RF), L4 erector spinae (L4-ES), and external oblique (EO) muscles activities during computer work. [Subjects] Fourteen computer workers were recruited. [Methods] The subjects performed computer work with and without an unstable dual foot support, and the muscle activities of the RF, L4-ES, EO were measured. [Results] The trunk flexion angle significantly decreased during working with the unstable dual foot support compared to without. The normalized EMG data of the RF, L4-ES and EO muscles significantly increased during working with the unstable dual foot support compared to without. [Conclusion] We suggest that the unstable dual foot support would be a portable and cost effective assistive tool for encourage an optimal sitting posture in computer workers.