Periscapular Muscle Activities and Kinematic Analysis of the Performed on Different Supporting Surfaces for the Lower Limbs Push-up Plus Exercise

摘要

[Purpose] This study examined periscapular muscle activities and performed a kinematic analysis of the push-up plus exercises with the lower limbs supported on a stable surface (bench) and an unstable surface (elastic ball). [Subjects and Method] The subjects were 15 college students. Surface electromyograms were recorded of the upper trapezius, serratus anterior, latissimus dorsl, and infraspinatus while the subjects performed the push-up plus exercises with their feet placed on a bench or an elastic gym ball. Markers for kinematic changes of elbow flexion, shoulder extension, shoulder retraction and scapular adduction were attatched the C7 and T7 spinous processes, both acromions, scapula superior and inferior angles, humeral lateral epicondyles, and ulnar styloid processes. The subjects completed three sets of push-up plus exercise. Three dimensional angles were calculated for the elbow, glenohumeral and scapulothoracic joint motions. The collected data were analyzed using the paired t-test and SPSS 18.0. [Result] There were statistically significant increase in the serratus anterior, infraspinatus, latissimus dorsi muscle activities during push-up plus exercise performed on the unstable surface, while the activity of upper trapezius increased during push up plus exercise performed on the stable surface. The angle of shoulder extension was significantly greater on the stable surface than on the unstable surface. The length of scapular adduction was significantly greater on the stable surface than on the unstable surface. [Conclusion] When the push-up plus exercise was performed on an unstable surface, recruitment of the periscapular muscles helped to stabilize the instable scapula.