中風是導致全球人口失能的重要原因。在台灣，中風疾病占健保醫療資源前三名且是造成年長者長期照顧負擔的主要病因。因此，藉由輔具科技來提昇中風患者的日常活動能力和減輕照顧者的負擔是非常重要的。對於長期保持坐姿狀態之行動不便的病患而言，要維持適當的擺位是十分困難的，特別是軀幹控制較差以及對坐姿的容忍度較差的患者。傾躺式輪椅不僅常用來當作運送病患的工具，在醫院和長照機構也被視為提供行動不便的病患舒緩坐姿不適的輔具。但它卻有造成使用者在傾躺後坐起時臀部會向前滑移因而增加尾骶骨壓力的缺失。現有一種新型且符合人體工程學“V型座椅”的設計，其目的為防止使用者向前滑動以及避免壓瘡的發生。本研究的動機來自傾躺式輪椅在中風病患的使用盛行但卻缺乏定量的效用評估，特別是對現有的肌肉張力異常之中風病患。
本研究的目在於評估V形座椅使用在中風病患的適用性以及量測不同的肌肉張力異常型態在輪椅擺位姿勢控制的影響。更具體地說，這項研究的目的是研究1）V形座椅和傳統式座椅在中風病人和正常老人，其向前滑移量和坐姿壓力的表現，及2）不同程度的肌肉張力之中風患者，在傾躺式輪椅上其向前滑移量和坐姿壓力的比較。
14位正常老人和行動不便之中風患者(弛緩型12位及痙攣型13位）參與本研究，受測者各在V形座椅與傳統式座椅之輪椅上進行3次的傾躺測試。量測其沿著背靠的滑移量（BS）、沿著坐墊的滑移量（SS）、平均坐墊壓力（MP）、和骶峰值壓力（SPP）。統計分析比較 BS、SS、MP、和SPP在兩種輪椅的差別，和在正常老人和中風病人的差別，以及作傾躺測試之趨勢分析。
本研究發現BS、SS和SPP在弛緩性偏癱中風受試者最大，其次是痙攣性偏癱的受試者，最後是行動正常的受試者。在大部分比較分析中，中風患者之BS、SS和SPP，在V形座椅顯著低於傳統式座椅；然而行動正常受試者的BS在V形座椅高於傳統式座椅。而中風患者在兩種輪椅上之SS和SPP 都顯著高於行動正常的受試者，且中風患者之BS只有在傳統式座椅上顯著高於行動正常的受試者。行動正常的受試者在傳統式座椅上有向前滑移的趨勢，但在V形座椅上卻有向後滑移的趨勢，然而偏癱患者在兩種座椅上，皆有向前滑移的趨勢。
弛緩性偏癱中風病人在傾躺輪椅上，是最容易發生骶骨坐姿及骶部褥瘡的族群，其次是痙攣性偏癱患者。在正常的肌張力和肌張力異常的受試者存在不同的滑移模式。高張肌張力有防止中風患者在重複傾躺過程中，造成進一步滑移的趨勢。V形座椅的使用，可以幫助減少弛緩性偏癱中風患者向前滑動和骶峰值壓力。而行動正常受試者之背靠滑移在兩種座椅上，不同於中風患者。這些結果在臨床處方傾躺式輪椅時，具有重要的參考價值；且可提供未來改善特製輪椅設計的生物力學基礎。

Stroke is the major cause of disability worldwide. In Taiwan, stroke is the third leading disease on the cost of healthcare resources and is related to major chronic diseases and disabilities, especially in the elderly. Therefore, intervention of assistive devices/technology to enhance the stroke patients’ daily activities and reduce the care burden is paramount. Reclining wheelchairs are commonly used not only as transportation tools but also as assistive devices for providing relaxation at reclined positions for non-ambulatory patients in hospital settings and nursing facilities. However, there is concern that the patient’s body in the wheelchair often slides forward and increases the sitting pressure when they return to a seated position. Therefore, a novel reclining wheelchair with an ergonomic "V-Seat" was designed to prevent forward sliding and pressure sores. This research is motivated by the huge demand of reclining wheelchairs for stroke patients with abnormal muscle tone from hemiplegia and the lack of quantitative evaluation for the effectiveness of these reclining wheelchairs.
The purpose of this research is to evaluate the effectiveness of V-shaped seats design for stroke patients and to quantitatively measure the impact of muscle tone on the postural control of wheelchair users. More specifically, this research is aimed to investigate 1) the effects of V-shaped and conventional seats in reclining wheelchairs on the forward sliding and sitting pressure of stroke patients and able-bodied elders, and 2) the impact of different levels of muscle tone on the forward sliding and sitting pressure of stroke patients while sitting in reclining wheelchairs.
Fourteen able-bodied elders and nonambulatory stroke patients with flaccid (n=12) or spastic hemiplegia (n=13) were recruited and conducted 3 reclining cycles in wheelchairs with conventional seats and V-shaped seats. The sliding along the backrest (BS) plane and the seat (SS) plane, mean sitting pressure (MP), and sacral peak pressure (SPP) of the participants were measured and recorded. The difference in BS, SS, MP, and SPP between the able-bodied elders and stroke patients, and between the two types seats were determined by statistical analysis. The trend across reclining cycles was also tested.
The BS, SS, and SPP during repeated reclining were generally greatest in flaccid hemiplegic participants, followed by spastic hemiplegic participants, and finally by able-bodied participants. The BS, SS, and SPP of stroke patients were significantly lower in the wheelchairs with V-shaped seats than in conventional wheelchairs in most comparisons; however, the BS of able-bodied elders was higher in V-shaped seats than in conventional seats. The SS and SPP of stroke patients were significantly higher than those of able-bodied elders in both types of reclining wheelchair, and the BS of stroke patients was significantly higher than that of able-bodied elders only in conventional reclining wheelchairs. Able-bodied participants’ buttocks tended to slide forward on conventional seats but backward on V-shaped seats, whereas hemiplegic participants’ buttocks slid forward on both seat types.

Stroke patients with flaccid hemiplegia are the most vulnerable to sacral sitting and sacral pressure sores in reclining wheelchairs, followed by patients with spastic hemiplegia. There is a discrepancy in the displacement pattern between participants with normal muscle tone and those with abnormal muscle tone during wheelchair positioning. The hypertonicity tends to prevent the stroke patients from further sliding during repetitive reclining. The use of V-shaped seats in reclining wheelchairs can help reduce the forward sliding and sacral peak pressure of stroke patients with flaccid hemiplegia. The back displacement of able-bodied subjects when using both conventional and V-shape seats in reclining positions differs from the back displacement of stroke patients when using such seats. These results are of paramount value and should be considered when prescribing the use of reclining wheelchairs.

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