輪椅使用者推進時腕關節之肌電圖與運動學分析

Wrist Kinematics and Electromyographic Analyses of Manual Wheelchair Propulsion

蔚順華(Shun-Hwa Wei) ； 曾明基(Ming-Chi Tseng) ； 黃紹禮(Shao-Li Huang) ； 江傳江(Chiang-Chuan Chiang)

《物理治療》 28卷4期 (2003/08) Pp. 199-208

摘要

目的：輪椅是下肢功能不全者，移動時主要的輔助工具。由於手腕就先天結構以及功能而言，是一活動關節而非承重關節(weight bearing joint)。但輪椅使用者由於得常用手去重複驅動輪椅，固此常導致腕關節部位的受傷。輪椅的人因設計必須先了解手腕在推進時的肌電及動作表現。本研究在測量與分析輪椅使用者，在輪椅推進期間，其腕關節之運動與腕伸肌及腕屈肌之肌電控制特徵。方法：本文研究共有9位資料完整的輪椅使用者參與，為順利取得腕關節之角度變化以及腕伸肌與腕屈肌之肌電訊號，本文研究採用固定式標準型輪椅為測試用輪椅。每位受試者共被收集5個頻道的電子訊號；分別為腕屈肌肌電圖，腕伸肌肌電圖，腕屈伸角度，腕橈尺偏角度以及為手掌面與手推輪之觸動開關。本文研究中將輪椅推進週期(propulsion)分為推動期(push phase)與恢復期(recovery phase)，來分析受試者手腕於其間的肌電控制與關節運動的行為表現。結果：腕關節在推進期間，始終保持在伸直姿勢。其最大伸直角度為27°，但過程中均末達到最大腕伸直角度。在橈偏尺偏移方面，手腕是以約8°的腕橈偏姿勢開始推動輪椅，手腕可達到最大橈偏角度16°，縮小手腕尺偏角度在推動期末期達到最大約26°。腕伸肌在推動期，以近乎30%的最大自主收縮程度做肌肉收縮。腕屈肌在推動期，比腕伸肌有較少的肌電圖興奮情形，其餘期間均近乎以15%的收縮程度。結論：輪椅使用者在所有推動期，未出現極端之腕伸、腕屈、橈偏或是尺偏的關節角度，但在每一個推進週期，受試者的手腕均得做出高反覆性的腕伸屈及橈尺偏動作。而且腕關節在輪椅推動期期間是長期處在伸直狀態，同時腕伸肌也一直呈現30%以上的最大自主收縮程度。本文認為輪椅使用者長期用手推動輪椅，除過分使用容易造成腕部傷害，特殊的手腕運動要求，亦是致病主因。未來輪椅合適的人因設計考量以減低輪椅使用者的腕部傷害是必要的。

關鍵字

輪椅使用者 ； 推進 ； 腕部疼痛 ； 肌電圖

並列摘要

Background: Wheelchair is one of the major options of locomotion for persons with disability. Proficient uses of manual wheelchair demand certain degree of functional status for the upper extremities. Unfortunately, musculoskeletal injures of the upper extremity such as wrist and shoulder injuries were frequently found in wheelchair users. To prevent wrist injury, the understanding of the wrist kinematic and electromyography (EMG) behaviors associated with wheelchair manual propulsion is important. Purposes: To investigate the wrist kinematic and EMG behaviors associated with manual wheelchair propulsion. Methods: Nine manual wheelchair users volunteered in this study. EMG electrodes and electrogoniometer were used to collect wrist motion and muscle activities. The wheelchair propulsion cycle was divided into push and recovery phases. Angular and EMG signals were simultaneously recorded. Results: Throughout the push phase, wrist always maintained an extension position. Maximal wrist extension was 27 ± 9°and occurred in the middle of push phase. Maximal radial deviation angle was 16 ± 4°and occurred in 20% of the propulsion cycle. Maximal ulnar deviation angle (26 ± 7°) happened at the end of push phase. Wrist extensor EMG maintained an activity level approximately 30% of the maximal voluntary contraction (MVC) during the push phase, whereas wrist flexor EMG was about 16% MVC. Conclusions: Although wrist didn't show excessive angle in either extension or deviation, highly repetitive nature of the wrist movement might be the reason for potential disorders. Another risk factor might be that manual wheelchair users frequently maintain their wrists in extension and results in an increased pressure within the carpal tunnel. Horizontal and vertical distances between the rotation axes of wheel and user's hip joint were believed to be an important factor affecting wrist kinematic characteristics. Therefore, appropriate ergonomic design of the manual wheelchair is crucial for preventing wrist pain in wheelchair user.

並列關鍵字

Wrist pain ； Manual propulsion ； Wheelchair user ； EMG