Muscle Strength and Age Effects in Balance Recovery

描述：从经济损失和人类痛苦的角度来看，与跌倒有关的伤害是工业和一般社会中的一个主要问题。尤其是老年人更容易受到与跌倒相关的伤害，因为跌倒的几率更高，摔倒受伤的可能性更大。随着年龄的增长，肌肉力量的下降被认为是老年人跌倒几率较高的一个因素，这一点得到了充分的证明。尽管有大量证据表明老年人较高的跌倒发生率与年龄相关的力量减少有关，但力量减少导致跌倒的具体生物力学机制仍不清楚。 根据之前的一项研究结果，即使个人能够完成试图恢复平衡的一个步骤，也会在绊倒后发生相当多的跌倒。因此，假设在步骤完成后发生的事件对平衡恢复至关重要。目前的研究将使用现有的平衡恢复实验模型来调查在采取一步恢复平衡后，踏步腿的关节扭矩不足，作为导致绊倒和跌倒事故的机制。如果这些力矩不足，它们将不能充分减速躯干角动量和/或不能阻止踏步腿的坍塌。其结果是，个人会摔倒。拟议的研究中概述的两个项目将1)建立年轻人平衡恢复过程中步态腿部关节扭矩的基线测量，以及2)将健康老年人平衡恢复过程中步态腿部关节扭矩的测量结果与年轻人的比较。这些项目的完成将为确定导致老年人跌倒的生物力学机制提供具体信息。这些信息可以用来制定特定的干预策略，如旨在预防跌倒的举重训练方案。

DESCRIPTION: Fall-related injuries are a major problem within industry and the general society when measured in terms of economic losses and human suffering. Older adults in particular are more susceptible to fall-related injuries due to higher fall rates and a greater likelihood of injury from a fall. The well documented reduction in muscle strength that occurs with aging is thought to be one factor contributing to the higher fall rates in older adults. Despite substantial evidence implicating age-related strength reductions in the higher falls rates among older adults, the specific biomechanical mechanism by which strength reductions contribute to falls remains unclear. Based on results from a previous study, a substantial number of falls occur after tripping even though individuals are able to complete a step in an attempt to recover their balance. It is thus hypothesized that events subsequent to step completion are critical to balance recovery. The current study will use an existing experimental model of balance recovery to investigate insufficient joint torques in the stepping leg, after taking a step to recover balance, as a mechanism contributing to tripping and falling accidents. If these torques are insufficient, they would not adequately decelerate trunk angular momentum and/or would not prevent the stepping leg from collapsing. As a result, the individual would fall. The two projects outlined in the proposed research will 1) establish baseline measurements of stepping leg joint torques during balance recovery in a young adult population, and 2) compare measurements of stepping leg joint torques in healthy older adults during balance recovery to those of young adults. Completion of these projects will provide specific information towards identifying biomechanical mechanisms that contribute to falls in older adults. This information can be used to develop specific intervention strategies, such as weight training regiments, aimed at fall prevention.