Background Fall-related head impact is the leading cause of traumatic brain injury in older adults. There is limited understanding of factors related to fall-related head impact. This investigation examined characteristics of upper limb movements during standing-height falls and examined their association with fall-related head impact in older adults at risk for falls. Methods Older adults (n=29) at risk for fall-related injuries underwent experimentally induced falls in multiple directions (backwards and sideways). To characterize the upper limb movements and their association with head impact, a standardized analysis tool was used to analyze a total of 164 video-recorded falls. The association between upper limb movements (and their characteristics) and head impact was analyzed through logistic regression. Results Nearly 80% of falls involved upper limb movements. Absence of upper limb movements significantly increased head impact odds by approximately 4-fold. The odds of head impact were reduced in falls with energy absorption at the forearm (0.013-fold) and upper arm (0.018-fold), compared to falls without upper limb energy absorption. Backwards falls showed significantly higher odds of head impact (more than 4-fold). Conclusion Upper limb movements are common during fall descent and are associated with lower odds of experiencing head impact. Energy absorption with the upper limb seems to be an important protective mechanism. Future work should explore if these movements can be augmented with targeted training.

中文翻译：

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上肢在限制实验室诱发的跌倒风险老年人跌倒期间的头部撞击中的作用


背景 与跌倒相关的头部撞击是老年人创伤性脑损伤的主要原因。对与跌倒相关的头部撞击相关因素的了解有限。这项调查检查了站立高度跌倒时上肢运动的特征，并检查了它们与有跌倒风险的老年人跌倒相关头部撞击的关系。方法 有跌倒相关损伤风险的老年人 （n=29） 接受了实验诱导的多个方向 （向后和侧向） 跌倒。为了描述上肢运动及其与头部撞击的关系，使用标准化分析工具分析了总共 164 次视频记录的跌倒。通过 logistic 回归分析上肢运动 （及其特征） 与头部撞击之间的关联。结果 近 80% 的跌倒涉及上肢运动。没有上肢运动显着增加了头部撞击的几率约 4 倍。与没有上肢能量吸收的跌倒相比，前臂 （0.013 倍） 和上臂 （0.018 倍） 吸收能量的跌倒时头部撞击的几率降低。向后跌倒显示头部撞击的几率明显更高（超过 4 倍）。结论 上肢运动在跌倒下降过程中很常见，并且与遭受头部撞击的几率较低有关。上肢吸收能量似乎是一种重要的保护机制。未来的工作应该探索是否可以通过有针对性的训练来增强这些动作。