Verschueren S M P, Brumagne S, Swinnen S P, Cordo P J
Department of Kinesiology, FLOK, Katholieke Universiteit Leuven, Tervuursevest 101, B-3001 Leuven, Belgium.
Behav Brain Res. 2002 Nov 15;136(2):593-603. doi: 10.1016/s0166-4328(02)00224-3.
The present study addressed whether dynamic position sense at the ankle--or sense of position and velocity during movement--shows a similar decline as a result of aging as previously described for static position sense and movement detection threshold. Additionally, the involvement of muscle spindle afferents in the possible age-related decline was studied. To assess dynamic position sense, blindfolded subjects had to open the hand briskly when the right ankle was rotating passively through a prescribed target angle. To assess the involvement of muscle spindles, the effect of tibialis anterior vibration was studied. The results showed that aging lead to a significant increase in deviation from the target angle at hand opening as well as in variability of performance. Vibration resulted in larger undershoot errors in the elderly compared to the young adults, suggesting that the age-related decline in performance on the dynamic position sense task is not (solely) due to muscle spindle function changes. Alternatively, this degeneration might be due to altered input from other sources of proprioceptive input, such as skin receptors. The elderly subjects did show a beneficial effect of practice with the task, which may provide solid fundaments for rehabilitation.
本研究探讨了踝关节的动态位置觉——即运动过程中的位置觉和速度觉——是否会如先前所述的静态位置觉和运动检测阈值那样，因衰老而出现类似程度的下降。此外，还研究了肌梭传入神经在可能与年龄相关的下降中所起的作用。为评估动态位置觉，蒙眼受试者在右踝关节被动旋转至规定目标角度时，需迅速张开手。为评估肌梭的作用，研究了胫前肌振动的影响。结果显示，衰老导致手张开时偏离目标角度的幅度显著增加，以及表现的变异性增大。与年轻成年人相比，振动在老年人中导致更大的下冲误差，这表明动态位置觉任务中与年龄相关的表现下降并非（ solely ）由于肌梭功能变化。或者，这种退化可能是由于来自其他本体感觉输入源（如皮肤感受器）的输入改变所致。老年受试者确实表现出练习该任务的有益效果，这可能为康复提供坚实的基础。
