AGE CHANGES IN RESPONSE SPEED AND NERVE CONDUCTION

年龄与运动的减缓和力量的丧失有关， 影响手臂和腿使用的准确性。在一个关键的水平，这可能是 是导致老年人功能性残疾的重要因素。的 这些变化是如何发生的自然历史和原因是不好的 明白在过去一年，完成了两项研究，以（1） 探讨年龄变化与运动速度时间的关系 神经功能对年龄的贡献 相关的力量损失。 对参与者进行了相互敲击测试， 巴尔的摩老龄化纵向研究。移动时间增加 横截面和纵向随着年龄的增长。40岁以后， 运动时间随着年龄的增长而增加， 击中目标。纵向上，准确性随着 年龄费特定律准确地描述了手的速度和准确性 在成人衰老过程中，跨队列和参与者内部的运动。 年龄相关的肌肉力量损失归因于肌肉减少 马萨诸塞州力量和质量都依赖于肌肉的神经支配。那里 很少有直接的人类证据表明年龄和 神经功能和强度的变化。中等程度，在较小程度上， 尺神经是提供握力的主要神经。握力 BLSA测定正中神经和尺神经传导速度 参与者正中神经而非尺神经与握力显著相关 力量沿着增长和前臂周长。年龄和初始握力 力量预测握力随年龄变化的速率。运动神经， 肌肉质量和年龄对年龄有显著的独立贡献 相关的强度水平。

Age is associated with a slowing of movement and loss of strength that affects the accuracy of arm and leg use. At a critical level this can be an important factor leading to functional disability in the elderly. The natural history of how these changes occur and the causes are poorly understood. During the past year, two studies were completed to (1) explore age changes in the relationship between speed of movement time and accuracy, and (2) the contribution of nerve function to age associated loss of strength. A reciprocal tapping test was administered to participants in the Baltimore Longitudinal Study of Aging (BLSA). Movement time increased cross-sectionally and longitudinally with increasing age. After age 40, movement time increases with age was linked to decreased consistency of hitting the targets. Longitudinally, accuracy decreased with increasing age. Fitt's law accurately described the speed and accuracy of hand movements during adult aging, across cohorts and within participants. Age associated muscle strength loss is attributed to decreasing muscle mass. Both strength and mass are dependent on muscle innervation. There is little direct human evidence demonstrating the association between age changes in nerve function and strength. Median and, to a lesser extent, ulnar nerves are the major nerves supplying grip strength. Grip strength and median and ulnar nerve conduction velocities were measured in BLSA participants. Median but not ulnar nerve significantly related to grip strength along with age and forearm circumference. Age and initial grip strength predicted rate of grip strength change with age. Motor nerves, muscle mass and age have significant, independent contributions to age associated levels of strength.