Bohm Sebastian, Mandla-Liebsch Martin, Mersmann Falk, Arampatzis Adamantios
Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.
Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany.
Front Sports Act Living. 2020 May 27;2:52. doi: 10.3389/fspor.2020.00052. eCollection 2020.
Age-related impairments of reactive motor responses to postural threats and reduced muscular capacities of the legs are key factors for the higher risk of falling in older people. It has been evidenced that a training of dynamic stability in the presence of perturbations has the potential to improve these deficits. However, the time course of training effects during such interventions is poorly understood. The purpose of this parallel-group study was to investigate the temporal adaptation dynamics of the balance recovery performance and leg strength during a dynamic stability training. Forty-two healthy older adults (65-85 years) were randomly assigned to a training ( = 27, analyzed = 18) or control group ( = 15, = 14). The training was conducted in a group setting for 6 weeks (3×/week, 45 min). The exercises focused on the mechanism of stability control (i.e., modulation of the base of support and segment counter-rotations around the center of mass) during standing, stepping, and jumping on unstable surfaces with a high balance intensity. Before, after 3 and after 6 weeks, the maximum plantar flexion moment and the knee extension moment were assessed. The recovery performance was evaluated by a simulated forward fall (lean-and-release test) and the margin of stability concept. The margin of stability at release decreased significantly after 3 weeks of training (34%, effect size = 0.79), which indicates fast improvements of balance recovery performance. The margin of stability further decreased after week 6 (53%, = 1.21), yet the difference between weeks 3 and 6 was not significant. Furthermore, the training led to significant increases in the plantar flexion moment after weeks 3 (12%, = 0.72) and 6 (13%, = 0.75) with no significant difference between weeks. For the knee extension moment, a significant increase was found only after week 6 (11%, = 1.07). The control group did not show any significant changes. This study provides evidence that a challenging training of dynamic stability in the presence of perturbations can improve balance recovery performance and leg strength of older adults already after a few weeks. Therefore, short-term training interventions using this paradigm may be an effective strategy for fall prevention in the elderly population, particularly when intervention time is limited.
与年龄相关的对姿势威胁的反应性运动反应受损以及腿部肌肉能力下降是老年人跌倒风险较高的关键因素。已有证据表明，在存在干扰的情况下进行动态稳定性训练有可能改善这些缺陷。然而，在此类干预过程中训练效果的时间进程却知之甚少。这项平行组研究的目的是调查动态稳定性训练期间平衡恢复表现和腿部力量的时间适应性动态变化。42名健康的老年人（65 - 85岁）被随机分配到训练组（n = 27，分析时n = 18）或对照组（n = 15，分析时n = 14）。训练以小组形式进行，为期6周（每周3次，每次45分钟）。练习重点在于在不稳定表面上站立、迈步和跳跃时的稳定性控制机制（即支撑面的调节以及围绕质心的节段反向旋转），平衡强度较高。在训练前、3周后和6周后，评估最大跖屈力矩和膝关节伸展力矩。通过模拟向前跌倒（倾斜 - 释放测试）和稳定性裕度概念来评估恢复表现。训练3周后，释放时的稳定性裕度显著降低（34%，效应量d = 0.79），这表明平衡恢复表现迅速改善。6周后稳定性裕度进一步降低（53%，d = 1.21），但3周和6周之间的差异不显著。此外，训练导致3周后（12%，d = 0.72）和6周后（13%，d = 0.75）跖屈力矩显著增加，各周之间无显著差异。对于膝关节伸展力矩，仅在6周后发现显著增加（11%，d = 1.07）。对照组未显示任何显著变化。这项研究提供了证据，即在存在干扰的情况下进行具有挑战性的动态稳定性训练，几周后就能改善老年人的平衡恢复表现和腿部力量。因此，使用这种模式的短期训练干预可能是预防老年人群跌倒的有效策略，特别是在干预时间有限的情况下。
