The Effects of Target Locations on Shifting of Center of Pressure during Whole Body Reaching in Normal Adults

全身伸臂取物時目標物位置對健康成年人壓力中心轉移的影響

陳貞夙(Jen-Suh Chern) ； 吳菁宜(Ching-Yi Wu) ； 楊世偉(Sai-Wei Yang)

《臺灣職能治療研究與實務雜誌》 1期 (2005/11) Pp. 1-11

https://doi.org/10.6534/jtotrp.2005.1(1).01

摘要

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.

關鍵字

全身伸臂取物 ； 目標物位置 ； 壓力中心 ； 承重對稱性

並列摘要

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.

並列關鍵字

Whole Body Reaching ； Target Location ； Center of Pressure ； Bilateral Loading Symmetry