輪椅前輪翹起之生物力學分析

前輪翹起是輪椅使用者實用的輪椅技巧之一，但臨床上發現多數輪椅使用者都不會此技巧。過去雖然有前輪翹起技巧訓練以及策略模式的相關文獻，然而前輪翹起過程的探討卻十分缺乏。因此本研究目的是針對前輪翹起過程中翹起期和平衡期進行生物力學分析，探究運動學和動力學表現與技巧相關性，以及了解不同性別的前輪翹起表現差異。共46位健康成年人(25位男性、21位女性)參與實驗，利用3維動作分析系統以及力板收集參與者前輪翹起定點平衡30秒3次，過程中記錄運動學及動力學資料。以相關係數檢定及獨立t檢定統計分析；並剖析圖形分類前翹類型。翹起期的結果顯示，前翹類型有三類：前-後前推型、後-前推型、前推型。其最大前輪翹起角度和最大手推輪施力沒有顯著相關。平衡期結果則顯示，前輪翹起角度與軀幹前傾角度、手推輪施力、有顯著相關；而前輪翹起角度變化和壓力中心變化以及質量中心變化都有顯著相關。質量中心-壓力中心連線距離和質量中心-壓力中心夾角對於前輪翹起角度都不具有相關性；但質量中心-壓力中心連線距離和軀幹前傾有顯著相關。性別則在運動學表現上有所差異，男性軀幹較為前傾質量中心變化也較大。本研究結論是前輪翹起平衡的姿勢控制主要與前輪翹起角度、質量中心、壓力中心、軀幹前傾角度等有關。翹起後前輪角度的晃動變化則可代表平衡狀態。初學者可選擇前-後-前推方式做為翹起輪椅的方法；翹起後，則應盡可能避免翹起角度晃動，以保持穩定的狀態。當輪椅翹起角度過高時，則可透過身體前傾來代償以取得平衡，但過多的身體前傾亦容易造成失去平衡的狀態。因此，維持前輪翹起的平衡需要去學習這一失一得之間的關係。

關鍵字

前輪翹起；輪椅生物力學；運動學；動力學

並列摘要

Wheelie is an advanced wheelchair skill; however, most wheelchair users did not know how to perform it. Previous study had indicated wheelie training and wheelie balance strategy; but, there was a lack of research literatures regarding wheelie performance. The purpose of this study was to investigate the biomechanics of wheelchair wheelie. We investigated the relationship between wheelie skill and balance by examining kinematic and kinetic variables, and investigating the difference due to gender effect. Forty-six health adults (25 male, and 21 female) popped and maintained a stationary wheelie for 30 seconds in three trails within a force plate. Kinematic and kinetic data during a wheelie activity were measured. The Pearson's correlation was used to find any significant correlation between kinematic and kinetic variables. Independent t-test was used to exam variables due to gender effect. Visual analysis during a wheelie was used to identify the take-off patterns. Results showed that there are three take-off patterns: 1) forward- -backward-forward pattern, 2) backward-forward pattern, and 3) forward only pattern. In the take-off phase, the pitch angle had no significant correlation with pitch force. In the balance phase, averaged pitch angle had significant positive correlation with trunk forward angles and force. The deviation of pitch angles increased significant in the sway of center of mass (COM) and center of pressure (COP). However, neither the COM-COP distance nor the COM-COP inclination angle had significant relationship with pitch angles. The COM-COP distance was significant correlation with the trunk forward angle. Kinematic variables showed the significant differences due to gender effect. Greater forward lean of the trunk angle and larger deviation of COM was found among male subjects. In conclusion, wheelie postural control had related to pitch angle, COM, COP, and trunk-forward angles. The sway of pitch angle during a stationary wheelie can be an indication of balance. The beginners should start with forward-backward-forward pattern to take-off the wheelchair. Once reaching a balance point, it should keep a steady pitch angle entirely to maintain the balance. If the pitch angle was too high, leaning forward could be compensated the balance. However, too much forward lean could loss the balance. Therefore, it is important to understand this phenomenon of losses and gains during a stationary wheelie.