The relationship between different hand positions on ground and joint loading in upper extremity during push-up exercise

• Main Authors: Wu, Tzung-Hsine, 吳宗憲
• Other Authors: You-Li Chou
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/12918585411332080851

碩士 === 國立成功大學 === 醫學工程學系 === 86 === Abstract Recently, as the incidence of trauma and arthritis increases in the upperextremity, clinical use of the total prosthesis for rheumatoid and post-traumaticarthritis and the resulting complications of prosthetic loosening the dislocationhave instigated the need to further understand the mechanism of joint disorderin the shoulder, the elbow, and the wrist joint. Hence, we will investigate thestatic and dynamic forces within the joints during simulated loading of theupper extremity. In this research, there are six sets of push-up exercises with differenthand positions(Normal, Apart, Together, Superior, Inferior, 2nd Normal). Tenhealthy male subjects,who were functionally right-handed, were instructed toperform a ''slow'' push-up of approximately 4 sec duration. Intersegmentalloading pattern across the upper extremity will be studied and recorded to establish a database; then, it will be compare the relationship between differenthands position and joint loading across the upper extremity during push-upexercise. In this study was combined Motion Analysis System and Force PlateSystem over the biomechanical model, inverse dynamics and computer programsto calaulate the joint force and joint moment by push-up exercises with differenthand positions. Experiment has shown that peak forces exerted on the elbow and wrist joint along the forearm axis averaged 46.9% of the the body weight for the''Normal'' hand position and were significantly decreased if hands werepositioned either ''apart'' or ''superior'' from ''normal''; furthermore, the peakforces exerted on the shoulder joint are the anterior-posterior shear force whichbrought a unstable foundation averaged 46.3% of the body weight for the''normal'' hand position. The peak torque in the ''normal'' position tends toproduce elbow flexion and was 1658.8 N-cm(50.6% of the maximal isometric extensor torque), also if hands were positioned ''Apart'' and ''Together''averaged 30%, 70.2% of the maximal isometric extensor torque. The maximalextension moment in the ''normal'' position tend to produce shoulder extensionand was 6203.8 N-cm, also if hands were positioned ''inferior'', the extensionmoment was significantly swelled to 7397.2 N-cm. The maximal torque aboutthe forearm axis is tended to produce forearm with a mean value of296.6 N-cm (33% of the maximal isometric supinator torque). The maximalvalgus torque at the elbow opposed by the medial ligamentous and geometricstructure was 998.6 N-cm and was significantly swelled to 1160 N-cm if thehand was positioned ''superior''. They have shown the different moments are exerted on the shoulder ifhands were positioned either ''superior'' or ''inferior'' from ''normal''. Thepeak torque was significantly decreased if hands were positioned ''superior'';teh peak torque was significantly increased if hands were positioned ''inferior''.Toward the differences between ''superior'' and ''inferior'',the shoulder adoptsthe different strategy to push-up. Hands positioned ''superior'' are the splay out;''inferior'' retact. The results in this study let us understand the pattern of thekinematics and the kinetics during push-up exercises, and will warrant a greaterunderstanding of the mechanism of injury extremity. Furthermore,these data will be helpful in clinical treatment and rehabilitation.