FALL BIOMECHANICS AND HIP FRACTURE RISK

描述（改编自申请人摘要）：福尔斯和跌倒相关 伤害是最严重、最常见和最昂贵的医疗问题之一 面对老人。 在美国，每年约有30万例髋部骨折。 美国，其中超过90%与福尔斯有关。 注意到以前的研究报告 研究了跌倒力学在髋部骨折病因学中的作用， 在上一个供资期间， 就在髋部撞击被确定之前。 这些信息被用来 估计冲击力，并开发分析模型， 将这些实验结果扩展到体弱的老年人。 申请人 在这些研究中，撞击速度对身体最敏感， 身高和冲击力与体重、主被动能 跌倒时下肢关节和肌肉的吸收 吸收大约71%的潜在能量，而这福尔斯落在 侧面是危险的，部分原因是臀部首先接触地面，即使 在年轻的志愿者被指示打破一个自我发起的“秋天”与 伸出的手。 申请人还表明，冲击力可以 随着躯干肌肉的激活， 转子软组织厚度使冲击力减小约三分之一， 并且平均跌落的冲击力超过 老年髋关节约35%。 最近，申请人和其他人进一步 从监测研究显示，福尔斯倒向一边，特别是那些 最后对髋部造成冲击，使髋部骨折的风险从6- 30倍，相比之下， 髋部骨矿物质密度的标准差降低。 然而， 尽管倒向一侧在病因学上具有明显的重要性， 先前关于姿势稳定性的研究主要集中在 前进的平面。 此外，虽然以前的研究有助于 确定那些因素，使老年人在高风险的下降，没有 以前的工作已经确定了受试者在下降到 侧或检查下肢力量不对称的影响， 反应时间，或肌肉骨骼病理作为潜在的风险因素， 从侧面落下的福尔斯。 考虑到髋部骨折的风险急剧增加， 目标1是了解 倒向一边。 由于预防跌倒的努力尚未 证明了伤害性福尔斯和跌倒风险的发生率降低 评估不能用来识别一小部分跌倒者， 将遭受髋部骨折，目标2是确定老年受试者在高 横向福尔斯的风险。 最后，由于髋骨骨折可以预防 通过降低确实发生的福尔斯坠落的严重程度，目标3建议 探索两种新的干预策略，一种侧重于减少影响， 另一个是冲击力。

DESCRIPTION (Adapted from the applicant's Abstract): Falls and fall related injuries are among the most serious, common and costly medical problems facing the elderly. There are about 300,000 hip fractures annually in the U.S., over 90% of them associated with falls. Noting that no previous study had examined the role of fall mechanics in the etiology of hip fracture, during the previous funding period, the configurations and velocities of fallers just before hip impact was determined. That information was used to estimate impact force, and to develop analytical models for interpreting and extending these experimental results to the frail elderly. The applicant showed, in these studies, that impact velocity is most sensitive to body height and impact force to body weight, that active and passive energy absorption in the joints and muscles of the lower extremity during falling absorb roughly 71% of the potential energy available and that falls to the side are dangerous in part because the hip contacts the ground first, even in young volunteers instructed to break a self-initiated "fall" with the outstretched hand. The applicant has also shown that impact forces can double with activation of the trunk muscles, that a 3-fold increase in trochanteric soft tissue thickness reduces impact force by about one-third, and that impact forces for an average fall exceed the strength of the elderly hip by about 35%. Recently, the applicant, and others, have further shown from surveillance studies that falls to the side, particularly those that end with impact on the hip, raise the risk of hip fracture from 6- to 30-fold, compared to about 3-fold increases in risk associated with one standard deviation reduction in bone mineral density at the hip. And yet, despite the apparently crucial etiologic importance of falling to the side, previous research on postural stability has largely focused on motion in the plane of progression. In addition, while previous studies have helped identify those factors that place the elderly at high risk for falling, no previous work has identified subjects at increased risk of falling to the side or examined the effects of asymmetries in lower extremity strength, reaction time, or musculoskeletal pathology as potential risk factors for sideways falls. Given the dramatically increased risk of hip fracture from a fall to the side, Aim 1 is to understand the fundamental dynamics of falling to the side. Since fall prevention efforts have not as yet demonstrated reductions in the incidence of injurious falls and fall risk assessments cannot be used to identify the small fraction of fallers who will suffer a hip fracture, Aim 2 is to identify elderly subjects at high risk for sideways falls. And finally, since hip fracture can be prevented by reducing the severity of those falls that do occur, Aim 3 proposes to explore two new intervention strategies, one focused on reducing impact velocity and the other on impact force.