Effect of elbow flexion on upper extremity impact forces during a fall
Effect of elbow flexion on upper extremity impact forces during a fall
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DOI：
10.1016/s0268-0033(01)00086-9
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发表时间：
2001-12-01
影响因子：
1.8
通讯作者：
Huang, GF
中科院分区：
文献类型：
--
作者：
Chou, PH;Chou, YL;Huang, GF
Objective.总体目标是开发一个生物力学模型的模拟下降与伸出的手。一项在大学研究实验室环境中进行的涉及年轻健康志愿者的横断面研究。很少有人知道的因素，影响骨折的风险，在下降过程中伸出的手。一组11名男性志愿者参加了这项调查。将一组8个反射标记物放置在选定的解剖标志的两侧。受试者被悬挂，肘部伸展，手腕背屈，准备从两个不同的坠落高度（3 cm和6 cm）撞击地面和力板。肘部采用两种不同的姿势。手肘伸展实验中，肘部一直伸展。在屈肘实验中，肘部在冲击时伸展，但随后立即弯曲，就像在俯卧撑练习的初始向下阶段一样。增加坠落高度会使上肢轴向力显著增加10%和5%。屈手肘和伸肘试验中施加于腕、肘或肩关节的轴向力无显著差异，但伸肘试验中肘关节内外侧剪切力大68%（P=0.002）。在冲击时执行肘屈曲运动减小了第一峰值冲击力值并且推迟了最大峰值。虽然将防坠落策略从肘部伸展改变为肘部屈曲并不影响手部的峰值冲击力，但它确实需要更大的肘部和肩部肌肉力量。
Objective. The overall objectives are to develop a biomechanical model for a simulated fall with outstretched hand.Design. Cross-sectional study involving young healthy volunteers in a university research laboratory setting.Background. Little is known about the factors which influence fracture risk during a fall on outstretched hand.Methods. A group of 11 male subjects volunteered for this investigation. A set of eight reflective markers was placed bilaterally on selected anatomic landmarks. Subjects were suspended with both elbows extended and wrists dorsiflexed, preparing to impact the ground and force plates from two different fall heights: 3 and 6 cm. Two different postures for the elbows were employed. In the elbow extension experiment, the elbows were extended at all times. In the elbow flexion experiment, the elbows were extended at impact, but then flexed immediately, as though in the initial downward phase of a push-up exercise.Result. Increasing the fall height significantly increased the upper extremity axial forces by 10% and 5%. No significantly different differences were found in the axial forces applied to the wrist, elbow or shoulder between the elbow flexion and elbow extension trials, but the elbow mediolateral shear force was 68% larger (P=0.002) in the extension trials.Conclusions. Performing an elbow flexion movement at impact reduces the first peak impact force value and postpones the maximum peak value. Although changing the fall arrest strategy from elbow extension to elbow flexion did not affect the peak impact force oil the hand, it did require substantially greater elbow and shoulder muscle strengths.