Muscle Strength and Age Effects in Balance Recovery

描述：当以经济损失和人类痛苦来衡量时，与跌倒有关的伤害是工业和一般社会中的一个主要问题。老年人尤其容易受到与跌倒有关的伤害，因为他们的跌倒率更高，跌倒受伤的可能性也更大。有充分证据表明，随着年龄的增长，肌肉力量会减少，这被认为是导致老年人跌倒率较高的一个因素。尽管有大量证据表明，老年人跌倒率较高与年龄相关的力量下降有关，但力量下降导致跌倒的具体生物力学机制尚不清楚。

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.