At matched loads, aging does not alter ankle, muscle, or tendon stiffness.
At matched loads, aging does not alter ankle, muscle, or tendon stiffness.
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在匹配的负荷下，衰老不会改变脚踝、肌肉或肌腱的硬度。
DOI：
10.1101/2023.11.25.568676
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Perreault,EricJ
中科院分区：
文献类型：
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作者：
Jakubowski,KristenL;Ludvig,Daniel;Lee,SabrinaSM;Perreault,EricJ
老年人在面对姿势障碍时难以保持平衡，这是一项受小腿三头肌和跟腱僵硬影响的任务。跟腱硬度的老化相关变化已经在匹配的努力水平的报告，但措施通常没有在匹配的负载，这是很重要的，由于年龄依赖性的力量变化。此外，肌肉硬度的年龄依赖性变化还有待测试。在这里，我们调查年龄如何改变肌肉和肌腱僵硬和踝关节僵硬的影响。我们假设与年龄相关的肌肉和肌腱变化有助于老年人踝关节僵硬度的降低，并在负荷或努力匹配时评估了这一假设。我们使用B型超声与关节水平的扰动，以量化踝关节，肌肉和肌腱刚度在一系列的负载和努力在17个健康的年轻人和老年人。在匹配的负荷下，两组之间的踝关节、肌肉或肌腱刚度没有显著差异（所有p>0.13）。然而，在匹配的努力，老年人表现出踝关节（27%; p=0.008），肌肉（37%; p=0.02）和肌腱刚度（22%; p=0.03）在30%的最大努力的显着下降。这与我们的发现一致，即老年人的跖屈比年轻人弱36%（p=0.004）。总之，这些结果表明，在本研究中测试的负载下，肌肉或肌腱的机械性能没有年龄依赖性变化，只有强度差异导致踝关节，肌肉和肌腱刚度在匹配的努力水平下发生变化。
Older adults have difficulty maintaining balance when faced with postural disturbances, a task that is influenced by the stiffness of the triceps surae and Achilles tendon. Age-related changes in Achilles tendon stiffness have been reported at matched levels of effort, but measures typically have not been made at matched loads, which is important due to age-dependent changes in strength. Moreover, age-dependent changes in muscle stiffness have yet to be tested. Here, we investigate how age alters muscle and tendon stiffness and their influence on ankle stiffness. We hypothesized that age-related changes in muscle and tendon contribute to reduced ankle stiffness in older adults and evaluated this hypothesis when either load or effort were matched. We used B-mode ultrasound with joint-level perturbations to quantify ankle, muscle, and tendon stiffness across a range of loads and efforts in seventeen healthy younger and older adults. At matched loads, there was no significant difference in ankle, muscle, or tendon stiffness between groups (all p>0.13). However, at matched effort, older adults exhibited a significant decrease in ankle (27%; p=0.008), muscle (37%; p=0.02), and tendon stiffness (22%; p=0.03) at 30% of maximum effort. This is consistent with our finding that older adults were 36% weaker than younger adults in plantarflexion (p=0.004). Together these results indicate that, at the loads tested in this study, there are no age-dependent changes in the mechanical properties of muscle or tendon, only differences in strength that result in altered ankle, muscle, and tendon stiffness at matched levels of effort.