OBJECTIVE: The aim of this study was to speculate the role of arm swing during gait through the comparison of energy consumption and kinematic data between the arm restriction and free arm swing METHOD: 20 healthy male adults were recruited as subjects. The kinematic data including upper trunk and oxygen consumption were compared at three different walking speeds (2 km/hr, 4 km/hr, 6 km/hr) between with and without arm restriction. RESULTS: The oxygen consumption rate with arm restriction was significantly increased at fast speed walking (6 km/hr) comparing that without arm restriction. We found the significant difference of anterior-tilt angle, range of motion (ROM) in the coronal and transverse plane of upper trunk, anterior pelvic tilting angle, ROM of pelvis in coronal and transverse plane, maximal flexion angle of hip, ROM of hip in the coronal plane, and the external rotation angle at single support time in the transverse plane of hip between with and without arm restriction at fast walking speed (p<0.05). CONCLUSION: These results revealed that arm restriction while walking resulted in the minimal, significant changes of energy consumption, and kinematic data. Therefore, arm swing on gait was considered to have roles on energy conservation at fast walking, and on getting better limb advancement and stability.