中文摘要
輪椅是目前脊髓損傷患者最常使用的代步工具，但是長時間使用手動輪椅容易造成上肢，尤其是肩關節的損傷，近年來殘障輪椅運動的風氣日益興盛，而輪椅後輪傾角，是運動輪椅的主要機構設計之一，但是目前相關的研究中，並沒有指出究竟輪椅後輪傾角會對我們上肢的肌肉施力產生何種影響，所以本篇研究主要的目的是改變輪椅後輪傾角，並且利用模擬的方法分析於不同的後輪傾角以及推進速度下，肩關節各個肌肉的作用力，藉此來探討輪椅後輪傾角對上肢所造成的影響。
本篇研究共有12位健康並且沒有使用輪椅經驗的受測者，利用動作分析系統擷取受測者之運動學資料，並用裝有測力計的輪圈收取動力學資料，再利用肩關節三維肌肉骨骼系統計算出13條肌肉的施力情形。本實驗所調整的後輪傾角分別為0˚、9˚、15˚，輪椅推動的速度控制在平均1m/s和2m/s，再分別對於速度和後輪傾角兩種變數進行分析比較。
實驗結果顯示，當輪椅推進速度增加時，推進期主要的作用肌群之作用時間加長以及作用力增加，在不同的後輪傾角下肌肉作用的型態不論是推進期或是恢復期都不會改變，改變的是肌肉的出力大小，其中前三角肌會隨著輪椅後輪傾角增加而增加出力，而胸大肌、肩胛下肌、小圓肌、棘下肌以及二頭肌在角度為9˚的時候出力最小。根據本研究可以提供輪椅使用者和設計者於選擇及設計輪椅時參考的依據，在推進效率及輪椅阻力之間找一個最佳化的平衡點。

Wheelchair is the most common device for individuals with spinal cord injury. It is very easy to make the upper extremity get hurt especially shoulder joint when long term using. The camber of the rear wheel is a common characteristic in sports wheelchair, and it is an important factor in wheelchair propulsion. However, the effect of camber on muscle forces of upper extremities hasn’t been studied in previous studies. The object of this research is to exam the effects of camber on shoulder muscle forces using simulation method to analysis the muscle force in different kinds of camber angle.
Twelve healthy subjects, who are unexperience wheelchair users, participated in this study. We use motion capture system to collect the kinematics data. An instrumented wheel with load cell was used to collect the force data. A previously built three dimensional shoulder musculoskeletal model was to calculate muscle forces of thirteen muscles around shoulder joint. In this research, participants were asked to propel wheelchair with 0˚, 9˚, and 15˚ rear wheel camber. Control the average wheelchair propulsion speed in 1m/s and 2m/s.
The results indicated that when the speed increase, the activation of the muscle groups activating during propulsion phase increase and maximum muscle force also became larger. Muscle activation pattern did not change with different camber angle. Anterior deltoid had greater muscle force when we increase camber angle. The other usually have minimum in 9˚ or have no significant difference. By the research, we also can provide some information to the wheelchair user and designer. Help them to find some optimal balance between the wheelchair resistance and fraction of effective force.

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