Ko Do-Kyung, Lee Hanall, Lee Hajun, Kang Nyeonju
Department of Human Movement Science, Incheon National University, Incheon, South Korea.
Neuromechanical Rehabilitation Research Laboratory, Incheon National University, Incheon, South Korea.
PLoS One. 2025 Mar 20;20(3):e0319578. doi: 10.1371/journal.pone.0319578. eCollection 2025.
Age-related impairments in ankle dorsiflexion force modulation are associated with gait and balance control deficits and greater fall risk in older adults. This study aimed to investigate age-related changes in bilateral ankle dorsiflexion force control capabilities compared with those for younger adults. The study enrolled 25 older and 25 younger adults. They performed bilateral ankle dorsiflexion force control at 10% and 40% of maximum voluntary contraction (MVC), for vision and no-vision conditions, respectively. Bilateral force control performances were evaluated by calculating force accuracy, variability, and complexity. To estimate bilateral force coordination between feet, vector coding and uncontrolled manifold variables were quantified. Additional correlation analyses were performed to determine potential relationships between age and force control variables in older adults. Older adults demonstrated significantly lower force accuracy with greater overshooting at 10% of MVC than those for younger adults. At 10% and 40% of MVC, older adults significantly showed more variable and less complex force outputs, and these patterns appeared in both vision and no-vision conditions. Moreover, older adults revealed significantly less anti-phase force coordination patterns and lower bilateral motor synergies with increased bad variability than younger adults. The correlation analyses found that lower complexity of bilateral forces was significantly related to increased age. These findings suggest that aging may impair sensorimotor control capabilities in the lower extremities. Considering the importance of ankle dorsiflexion for executing many activities of daily living, future studies may focus on developing training programs for advancing bilateral ankle dorsiflexion force control capabilities.
踝关节背屈力调节方面与年龄相关的损伤与老年人的步态和平衡控制缺陷以及更高的跌倒风险相关。本研究旨在调查与年轻人相比，双侧踝关节背屈力控制能力的年龄相关变化。该研究招募了25名老年人和25名年轻人。他们分别在最大自主收缩（MVC）的10%和40%下，在有视觉和无视觉条件下进行双侧踝关节背屈力控制。通过计算力的准确性、变异性和复杂性来评估双侧力控制表现。为了估计双脚之间的双侧力协调，对矢量编码和非受控流形变量进行了量化。还进行了额外的相关性分析，以确定老年人年龄与力控制变量之间的潜在关系。与年轻人相比，老年人在MVC的10%时表现出明显更低的力准确性，且超调更大。在MVC的10%和40%时，老年人明显表现出更可变且更不复杂的力输出，并且这些模式在有视觉和无视觉条件下均出现。此外，与年轻人相比，老年人表现出明显更少的反相力协调模式和更低的双侧运动协同作用，且不良变异性增加。相关性分析发现，双侧力的较低复杂性与年龄增长显著相关。这些发现表明，衰老可能会损害下肢的感觉运动控制能力。考虑到踝关节背屈对于执行许多日常生活活动的重要性，未来的研究可能会集中于开发训练计划以提高双侧踝关节背屈力控制能力。
