過去文獻指出，硬式靠背在靜態時能有效改善軀幹駝背姿勢與提供軀幹穩定性。然而目前硬式靠背在動態輪椅推進過程中對於軀幹姿勢影響的研究仍相當缺乏。本研究目的在於比較硬式靠背與帆布靠背在不同坡度情境下對於輪椅推動的運動學(kinematics)與動力學(kinetics)表現的差異，以探討硬式靠背對於輪椅使用者軀幹駝背姿勢改善與推進效益。本研究方法採用重複施測的方式，共二十六位下肢癱瘓之脊髓損傷輪椅使用者參與實驗。受測者分別使用硬式靠背與帆布靠背在一輪椅運動平台上進行以相同速度(0.9m/s)在兩種不同坡度(水平、與3 度)的情境下進行輪椅推進測試，過程中分別記錄其運動學與動力學資料。本研究利用重複量數雙因子變異數分析(Repeated Measurement Two-way ANOVA)來驗證以不同靠背及不同坡度為主要影響因子(main effect)對於運動學與動力學資料等依變項的差異性。結果顯示，硬式靠背能給予輪椅使用者額外軀幹支持性，使軀幹較為挺直及明顯減少駝背姿勢，降低無效方向力量的損耗，進而增加推進效益。臨床應用上可建議因缺乏軀幹控制而習慣駝背坐姿者，選用硬式靠背作為改善駝背坐姿介入方法之一。此外，對於經常需要於日常生活中從事輪椅推動活動之輪椅使用者而言，亦可透過選用硬性靠背，藉以減少力量損耗及提昇推進效益的表現，來降低日常生活輪椅行動之障
礙。

Previous studies indicated that the rigid backrest could improve the
kyphotic posture and provide sufficient trunk stability in static state. However,there are few studies to investigate the effect of rigid backrest on trunk stability during dynamic wheelchair propulsion. The purpose of this study was to investigate whether the use of the rigid backrest in comparison with the standard sling backrest increased propulsion efficiency and reduced kyphotic posture by examining kinematic and kinetic variables during different propulsion slope conditions. A repeated measurement design was used in this study. 26 manual wheelchair users with spinal cord injuries participated in this study. Participants
were instructed to propel at two different slope conditions (on a level surface and 3-degree slope) with steady-state speeds of 0.9m/s on a motor driven treadmill while using rigid backrest and standard sling backrest respectively.Biomechanical data, such as kinematic and kinetic variables, were collected during trials. Based on the main aims of this study, a two-way repeated measure analysis of variance (ANOVAs) was used to examine the main effect of different backrests on kinematic and kinetic variables. The results showed that the rigid backrest could provide extra trunk stability and keep the user in more upright posture. Therefore, it could significantly reduce kyphotic posture,decrease the waste of propulsion force, and increase propulsion efficiency. It was suggested that manual wheelchair users adopted a kyphotic posture due to lack of trunk control could use the rigid backrest to reduce their kyphosis.
Moreover, for those manual wheelchair users who may encounter demanding
propulsion conditions with many activities of daily life, the use of rigid backrest might help them overcome difficulties with less force waste and high propulsion efficiency.