Kwon MinHyuk, Baweja Harsimran S, Christou Evangelos A
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
J Mot Behav. 2011;43(5):357-60. doi: 10.1080/00222895.2011.598893. Epub 2011 Aug 2.
The authors' purpose was to determine the interaction of age and limb used on positional variability at different loads. Eleven young adults and 10 older adults were asked to accurately match and maintain a horizontal target line with 5° abduction of their index finger and 5° dorsiflexion of their ankle for 20 s at loads ranging from 2 to 50% of the maximal load that could be lifted with each limb. The visual gain was kept constant at 1° (visual angle). Positional variability was greater in older adults for both limbs, nonetheless age-associated differences were greater for the ankle dorsiflexion task compared with the abduction of the index finger task. In addition, we found that, independent of age, motor output variability was greater with the lower limb. These results provide novel evidence that older adults may exhibit greater impairments in motor control with the foot compared with the finger. Furthermore, these findings support the idea, using a different task than previous literature, that the lower limb has greater motor output variability than the upper limb.
作者的目的是确定年龄和使用的肢体对不同负荷下位置变异性的相互作用。研究要求11名年轻成年人和10名老年人，在每个肢体可举起的最大负荷的2%至50%的负荷范围内，将食指外展5°和踝关节背屈5°，精确匹配并保持一条水平目标线20秒。视觉增益保持在1°（视角）不变。两个肢体在老年人中的位置变异性都更大，尽管如此，与食指外展任务相比，踝关节背屈任务中与年龄相关的差异更大。此外，我们发现，与年龄无关，下肢的运动输出变异性更大。这些结果提供了新的证据，表明与手指相比，老年人在足部的运动控制方面可能表现出更大的损伤。此外，这些发现支持了这样一种观点，即与先前文献中使用的不同任务相比，下肢的运动输出变异性比上肢更大。
