BIOMECHANICS OF STEPPING RESPONSES--EFFECTS OF AGING

本研究的长期目标是：（1）识别 可预防和可治疗的跌倒原因， 疾病，（2）制定临床实用的干预措施， 有效减少长者跌倒的机会。在 与其他研究人员暗示或明确表达的相反， 与年龄相关的静态姿势摇摆增加与 下降的行为，我们的工作导致了争论， 通常观察到（但不是强制性的）与年龄相关的静态增加 姿势摇摆不会使人容易跌倒。而且 假设在其他健康的情况下，老年人福尔斯 由于无法恢复， 姿势稳定性，主要是由于年龄相关的减少， 产生和协调多个肌肉/关节（下肢）的能力 和树干）的权力。这项研究的独特之处在于它将诱导 需要步进反应的大的姿势扰动， 姿势稳定性的恢复越来越困难， 可能肌肉力量变量假设是至关重要的 将根据每个姿势扰动计算稳定性的恢复 条件下，这些变量的临床可测量的相关性 在相同的主题中测量，以及这些之间的关系 变量和下降的可能性特征。具体目标 本研究的目的是（1）确定测量之间的关系 静态姿势稳定性和跌倒的可能性 需要步进反应的大姿势扰动;（2） 描述踏步的关键运动学和动力学决定因素 与成功恢复姿势相关的反应 （a）从静态不稳定状态突然释放后的稳定性 位置，（B）支架的突然加速和持续运动 表面，（c）在运动过程中引起的跳闸;（3）建立 下肢（踝和膝）与躯干的关系 可以在实验室/诊所测量的肌肉力量， 在具体目标2的实验中摔倒的可能性。这 研究将确定特定的年龄相关的缺陷，在神经肌肉 与恢复姿势稳定性能力下降相关的系统 在大的姿势扰动之后， 具体的临床干预。最终，这项研究将有助于 改善和延长老年人的独立生活方式 从而对生活质量和经济产生积极影响， 衰老的迹象

The long-term objectives of this research are to: (1) identify preventable and treatable causes of falling that are unrelated to disease, and (2) to develop clinically practical interventions that will be effective in reducing the incidence of falling in elderly people. In contrast to other investigators who imply, or explicitly express a relationship between age-related increases in static postural sway and falling behavior, our work has resulted in the contention that the commonly observed (but not obligatory) age-related increase in static postural sway does not predispose a person to falling. Furthermore, it is hypothesized that in otherwise healthy, elderly people falls result following large postural perturbations from an inability to restore postural stability due, primarily to an age-related decrease in the ability to generate and coordinate multiple muscle/joint (lower extremity and trunk) powers. The proposed research is unique in that it will induce large postural perturbations that require stepping responses and to which recovery of postural stability is increasingly difficult and not always possible. The muscle power variables hypothesized to be crucial to recovery of stability will be computed from each postural perturbation condition, the clinically measurable correlates of these variables measured in the same subjects, and the relationships between these variables and the likelihood of falling characterized. The specific aims of this research are to (1) determine the relationships between measures of static postural stability and the likelihood of falling subsequent to large postural perturbations that require stepping responses; (2) characterize the critical kinematic and kinetic determinants of stepping responses that are associated with successful restoration of postural stability following (a) sudden release from statically unstable positions, (b) sudden accelerations and continued motion of the support surface, (c) trips induced during locomotion; (3) to establish the relationship between the lower extremity (ankle and knee) and trunk muscle powers that may be measured in the laboratory/clinic and the likelihood of falling during the experiments of Specific Aim 2. This research will identify specific age-related deficits in the neuromuscular system related to decreased ability to recover postural stability following large postural perturbations and provide direction toward specific clinical intervention. Ultimately, this research will contribute to improving and extending the independent lifestyles of elderly people thereby having a positive effect on the quality of life and the economics of aging.