Robinovitch S N
Biomechanics Laboratory Department of Orthopaedic Surgery, San Francisco General Hospital University of California.
J Mot Behav. 1998 Dec;30(4):352-8. doi: 10.1080/00222899809601349.
The relationship between perceived and actual postural limits in reaching by healthy young and middle-aged participants was assessed. Subjects (N = 51) first estimated their expected performance and then executed maximum reaches along a tape measure mounted at shoulder height. Measures of standing and bending reaches were obtained. Subjects estimated their reach limits reasonably accurately but significantly underestimated bending reach and overestimated standing reach. That finding suggests that individuals scale perceived abilities with perceived risk in attempting a given action. The accuracy of a participant's perceived bending reach was unrelated to his or her height, weight, age, and gender, and was only weakly correlated with actual reach excursion (bending - standing reach). The accuracy was strongly correlated with the accuracy of subjects' perceived standing reach; individuals who underestimated standing reach underestimated bending reach much more. That result and the observed lack of correlation between the magnitudes of estimated bending reach and estimated standing reach suggest a serial strategy of estimating bending reach by considering and summing perceived arm's length and perceived reach excursion.
评估了健康的年轻和中年参与者在伸手够物时感知到的姿势极限与实际姿势极限之间的关系。受试者（N = 51）首先估计他们预期的表现，然后沿着安装在肩部高度的卷尺进行最大程度的伸手动作。获得了站立和弯腰伸手的测量数据。受试者对其伸手极限的估计相当准确，但显著低估了弯腰伸手的距离，高估了站立伸手的距离。这一发现表明，个体在尝试特定动作时会根据感知到的风险来衡量感知到的能力。参与者对弯腰伸手的感知准确性与其身高、体重、年龄和性别无关，仅与实际伸手距离（弯腰 - 站立伸手距离）存在微弱关联。该准确性与受试者对站立伸手的感知准确性密切相关；低估站立伸手距离的个体对弯腰伸手距离的低估程度要大得多。这一结果以及观察到的估计弯腰伸手距离和估计站立伸手距离的大小之间缺乏相关性，表明了一种通过考虑并累加感知到的手臂长度和感知到的伸手距离来估计弯腰伸手距离的连续策略。
