Greve Christian, Hortobágyi Tibor, Bongers Raoul M
Center for Human Movement Science, University of Groningen, University Medical Center Groningen, Hanzeplein 1, HPC CB41, Postbus 30.001, 9700 RB, Groningen, The Netherlands.
Department of Rehabilitation Medicine, Center for Rehabilitation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Eur J Appl Physiol. 2017 May;117(5):955-967. doi: 10.1007/s00421-017-3584-2. Epub 2017 Mar 14.
Our ability to flexibly coordinate the available degrees of freedom allows us to perform activities of daily living under various task constraints. Healthy old adults exhibit subclinical peripheral and central nervous system dysfunctions, possibly compromising the flexibility in inter-joint coordination during voluntary movements and the ability to adapt to varying task constraints.
We examined how healthy old (75.4 ± 5.2 years, n = 14) compared with young adults (24.3 ± 2 years, n = 15) make use of the available motor flexibility to adapt to physical and dexterity constraints during a rapid goal-directed reaching task. We manipulated physical and dexterity demands by changing, respectively, external resistance and target size. Motor flexibility was quantified by an uncontrolled manifold (UCM) analysis.
We found that healthy young and old adults employ similar motor flexibility as quantified by the ratio between goal equivalent and non-goal equivalent variability (V ) and were similarly able to adapt to increases in physical and dexterity demands during goal-directed rapid reaching (V : p = .092; young: 0.548 ± 0.113; old: 0.264 ± 0.117). Age affected end-effector kinematics. Motor flexibility and end-effector kinematics did not correlate.
The data challenge the prevailing view that old age affects movement capabilities in general and provide specific evidence that healthy old adults preserve motor flexibility during a reaching task. Future studies applying UCM analysis should examine if experimental set-ups limit movement exploration, leaving possible age differences undetected.
我们灵活协调可用自由度的能力使我们能够在各种任务限制下进行日常生活活动。健康的老年人表现出亚临床的外周和中枢神经系统功能障碍，这可能会损害自愿运动期间关节间协调的灵活性以及适应不同任务限制的能力。
我们研究了健康的老年人（75.4±5.2岁，n = 14）与年轻人（24.3±2岁，n = 15）在快速目标导向伸手任务中如何利用可用的运动灵活性来适应身体和灵巧性限制。我们分别通过改变外部阻力和目标大小来操纵身体和灵巧性需求。运动灵活性通过非受控流形（UCM）分析进行量化。
我们发现，通过目标等效与非目标等效变异性（V）之比量化，健康的年轻人和老年人采用了相似的运动灵活性，并且在目标导向的快速伸手过程中同样能够适应身体和灵巧性需求的增加（V：p = 0.092；年轻人：0.548±0.113；老年人：0.264±0.117）。年龄影响末端执行器运动学。运动灵活性和末端执行器运动学不相关。
这些数据挑战了普遍观点，即老年通常会影响运动能力，并提供了具体证据表明健康的老年人在伸手任务中保持运动灵活性。未来应用UCM分析的研究应检查实验设置是否限制了运动探索，从而未发现可能的年龄差异。
