目的：全身性伸臂取物(whole body reaching)是獨立日常生活必要的動作任務之一多年以來，臨床上將其改裝為撿沙包的活動，藉由改變沙包（取物目標物）的位置，來評估與誘發病患調整姿勢控制的能力。然而至今仍然缺乏證據支持WBR在姿勢控制能力的評估與訓練的效果。本研究之目的為探究正常成年人在執行全身性伸臂取物動作時，雙側承重的變化與壓力中心移動量受目標物的距離與方向影響的程度。方法：本實驗共取正常成年且無任何會影響平衡能力病史的志願者共15名。其中6名女性、9名男性，平均年齡32歲，平均身高163公分，平均足長24公分，慣用側均為右側。這些受試者以隨機的方式以慣用手執行六種目標位置物情境（兩種距離，三種方向）下的全身性伸臂取物動作，同時以足底壓力量測系統量得雙側承重的變化與壓力中心移動量。原始資料經過正規化後，以配對T檢定與重複量數單因子變異數分析，來檢驗雙側承重的變化與足底壓力中心移動量受目標物距離與方向的影響情形。結果：結果顯示，當目標物偏右與偏左時，距離對雙側承重的變化與足底壓力中心移動量均有顯著的影響(p<.05)；當目標物位於中線方向時，除了雙側承重的變化未達顯著影響外，目標物距離對壓力中心移動量均造成顯著影響。至於雙側承重轉移的狀況與壓力中心移動的量，在不同的方向上，目標物距離所造成的影響並不一致。此外，無論目標物距離的遠近，雙側承重狀況受目標物方向顯著的影響(p<.05)；當目標物在較近的距離時，壓力中心的移動量與速度並未受到顯著影響；當目標物在較遠距離時，目標物的方向只對壓力中心在前後與左右的移動量造成顯著影響(p<.05)。結論：以上研究結果顯示，正常成年人在執行WBR動作任務時，其雙側承重狀況與壓力中心移動量同時受到目標物距離與方向的影響，因此，臨床上病患執行撿沙包活動時，治療師依據病患的的能力改變沙包的距離與方向，應該有誘發病患雙側承重轉移與重心轉移的效果，然而，進一步探討病患執行時的狀況是有必要的。此外，有些不一致的結果可能與動作過程中所探取的動作策略不同有關，建議未來的研究應該加入肌電圖與動作分析，以深入探討全身伸臂取物時的動作機制。

Whole body reaching (WBR) is required for independent living and has been used as a balance training activity. The purpose of this study was to investigate the influences of target locations on bilateral loading symmetry, the amount of COP shifting and the velocity of COP shifting of normal adults. Methods: Fifteen normal adults (6 females and 9 males) were recruited for the study through convenient sampling (average age: 32 yr; average body height: 163 cm; average foot length: 24 cm; all being right-handed). All subjects had to perform 18 trials (2 distances × 3 directions × 3 repetitions) of WBR while standing on a pressure measurement mat. Bilateral loading symmetry, COP total path length, maximum COP displacement in posterior/anterior and medial/lateral direction, average and maximum COP velocity were measured, normalized, and averaged for statistical analysis. Paired t-test and repeated measures analyses of variance were used to examine the effects of target locations on the outcome parameters. Results: The results showed that bilateral loading and COP-related parameters were significantly influenced by target distance when the reaching was made for left- and right-located targets (p<.05). When the targets were in the middle, all parameters except for bilateral loading symmetry were influenced significantly by target distance. The influences of target distance on all parameters were not consistent. The effects of target direction on bilateral loading were significant (p<.05) and the effects on measures for COP shifting were more prominent when the target was near than when the target was far. Conclusion: The results of this study showed that bilateral loading and COP shifting were influenced by both target distance and direction during WBR. This result provided the preliminary evidence to support clinical practice of using WBR as a training activity to facilitate shifting of body weight and COP. Evaluation of performance of WBR by clinical populations needs to be investigated to generate practice-relevant hypotheses. EMG and kinematic data are needed to interpret the inconsistent results possibly due to differential movement strategies.