背景與目的：本研究以兩個單軸測力板來蒐集坐到站的過程中兩腳的承重分布，並利用不同的參數來比較中風患者在承重偏好腳、對稱性與花費時間等三方面是否仍與健康人有差異及其差異程度。方法：共有13 位具社區獨立行走能力的輕微偏癱中風患者與20 位健康年輕人參與本研究。每位受試者皆須在兩個測力板上執行坐到站任務，以測力板所蒐集到的反作用力經過處理後的參數如下：(1) 承重比率偏好腳、時間偏好腳及承重偏好腳之交換次數；(2) 兩腳各自之承重比率之差值、兩腳瞬間承重比率差值絕對值的平均、兩腳瞬間耗能差累積；(3) 坐到站花費總時間、預備期及起身期所費時間與最大反作用力之發生時間百分位。結果：本研究結果顯示大部分健康年輕人的承重偏好腳是非慣用腳，而中風患者則是在健側腳且中風患者較健康人不對稱，在轉移效率上也花費較多時間。結論：本研究提出的坐到站新力學指標可有效偵測中風患者在執行坐到站期間的不對稱現象。

Background and Purpose: Vertical ground reaction forces (vGRFs) were recorded by means of two equal force plates to examine the inter-leg of weight-bearing distribution during the sit-to-stand (STS) transfer task in all participants. Different force variables were used to define various indices related to weight-bearing preference leg, weight-bearing symmetry, and sit-to-stand duration. In addition, this study also compared the difference of these forces variables between individuals with hemiparetic stroke and young healthy adults. Methods: All of the 13 independently ambulant, community-dwelling stroke survivors (58.5 ± 16.0 years) and 20 young healthy adults (23.4 ± 1.1 years) completed the STS transfer task on an adjusted chair at their natural speed. vGRF was measured by means of one force plate under each foot. Force variables in three various indices were defined: (1) indices of weight-bearing preference leg: including more weight or more duration on which leg and numbers of weight-preference exchanges; (2) indices of weight-bearing symmetry: difference of mean weight-bearing percentage between two legs, absolute value of instantaneous difference of inter-leg weight-bearing percentage, mean square difference ;(3) indices if sit-to-stand duration: total rise time, time of preparatory, and extension phase, relative occurrence of peak vGRF. Results: (1) Most young adults had more weight and duration to weight-bearing on the non-dominant leg, and most stroke patients had the non-affected leg as their preference leg; (2) All 3 indices of weight-bearing symmetry indicated larger asymmetry in hemiparetic participants (all p < 0.05); (3) The hemiparetic participants had longer rise time than the young adults (p < 0.05), but relative occurrence of peak vGRF (Tpeak %) did not differ significantly between the two groups (p = 0.05). Conclusions: Even though the hemiparetic participants could independently community walking, these patients still performed the STS transfer asymmertrically and had longer rising time than the young persons. These vGRF parameters analyzed in this study can accurately reflect the weight-bearing asymmetry during an STS movement in stroke patients with lower hemiparetic limb.