Kulig K, Rao S S, Mulroy S J, Newsam C J, Gronley J K, Bontrager E L, Perry J
University of Southern California, Department of Biokinesiology and Physical Therapy, Los Angeles, USA.
Clin Orthop Relat Res. 1998 Sep(354):132-43. doi: 10.1097/00003086-199809000-00016.
The purpose of this investigation was to quantify the forces and moments at the shoulder joint during free, level wheelchair propulsion and to document changes imposed by increased speed, inclined terrain, and 15 minutes of continuous propulsion. Data were collected using a six-camera VICON motion analysis system, a strain gauge instrumented wheel, and a wheelchair ergometer. Seventeen men with low level paraplegia participated in this study. Shoulder joint forces and moments were calculated using a three-dimensional model applying the inverse dynamics approach. During free propulsion, peak shoulder joint forces were in the posterior (46 N) and superior directions (14 N), producing a peak resultant force of 51 N at an angle of 185 degrees (180 degrees = posterior). Peak shoulder joint moments were greatest in extension (14 Newton-meters [Nm]), followed by abduction (10 Nm), and internal rotation (6 Nm). With fast and inclined propulsion, peak vertical force increased by greater than 360%, and the increase in posterior force and shoulder moments ranged from 107% to 167%. At the end of 15 minutes of continuous free propulsion, there were no significant changes compared with short duration free propulsion. The increased joint loads documented during fast and inclined propulsion could lead to compression of subacromial structures against the overlying acromion.
本研究的目的是量化自由、水平轮椅推进过程中肩关节的力和力矩，并记录速度增加、地形倾斜以及连续推进15分钟所带来的变化。使用六摄像头VICON运动分析系统、应变片测量轮和轮椅测力计收集数据。17名低位截瘫男性参与了本研究。采用逆动力学方法，通过三维模型计算肩关节的力和力矩。在自由推进过程中，肩关节力峰值出现在后方（46牛）和上方（14牛），在185度角（180度=后方）产生51牛的合力峰值。肩关节力矩峰值在伸展时最大（14牛顿米[Nm]），其次是外展（10 Nm）和内旋（6 Nm）。在快速和倾斜推进时，垂直力峰值增加超过360%，后方力和肩关节力矩的增加范围为107%至167%。在连续自由推进15分钟结束时，与短时间自由推进相比没有显著变化。快速和倾斜推进过程中记录到的关节负荷增加可能导致肩峰下结构受到上方肩峰的挤压。
