Lee-Confer Jonathan S, Lo Matthew K, Troy Karen L
Department of Physical Therapy, University of Arizona, Tucson, AZ, USA.
Department of Physiology, University of Arizona, Tucson, AZ, USA.
Sci Rep. 2025 May 6;15(1):15727. doi: 10.1038/s41598-025-00412-9.
Arm abduction motion can help reduce lateral center of mass (CoM) excursion and restore balance within the frontal plane during slip perturbations. This study aimed to quantify and compare frontal plane arm kinematics and their relationship with CoM control between older and younger adults experiencing a slip. Eleven older adults (age: 72.0 ± 5.0 years) and eleven younger adults (age: 25.5 ± 6.1 years) underwent an induced slip perturbation while walking. Although peak arm abduction angles were similar between groups, younger adults achieved peak arm abduction significantly earlier (542 ± 67 ms) compared to older adults (853 ± 509 ms; p = 0.03). Additionally, younger adults exhibited significantly higher peak arm abduction acceleration compared to older adults (3593.21 ± 1144.80 vs. 2309.83 ± 1428.48 degrees/s; p = 0.03). Younger adults also demonstrated significantly reduced lateral CoM excursion relative to older adults (4.6 ± 3.5 cm vs. 10.47 ± 6.6 cm; p < 0.01). Peak arm abduction acceleration negatively correlated with lateral CoM excursion (r = -0.52, p < 0.02), indicating that rapid arm movements are associated with improved balance control. A regression analysis confirmed arm abduction acceleration as a significant predictor of lateral CoM displacement (p = 0.005) meaning every 1000 degrees/s increase in arm acceleration results in an approximate 2 cm decrease in lateral CoM displacement during a slip. These findings suggest older adults' diminished arm acceleration in response to slips potentially compromises their ability to stabilize their CoM effectively, highlighting a possible target for fall-prevention interventions.
手臂外展动作有助于减少侧向重心（CoM）偏移，并在滑倒扰动期间恢复额状面内的平衡。本研究旨在量化和比较老年人和年轻人在滑倒时额状面手臂运动学及其与CoM控制的关系。11名老年人（年龄：72.0±5.0岁）和11名年轻人（年龄：25.5±6.1岁）在行走时经历了诱发的滑倒扰动。尽管两组之间的峰值手臂外展角度相似，但与老年人（853±509毫秒）相比，年轻人达到峰值手臂外展的时间明显更早（542±67毫秒；p=0.03）。此外，与老年人相比，年轻人的峰值手臂外展加速度明显更高（3593.21±1144.80对2309.83±1428.48度/秒；p=0.03）。与老年人相比，年轻人的侧向CoM偏移也明显减少（4.6±3.5厘米对10.47±6.6厘米；p<0.01）。峰值手臂外展加速度与侧向CoM偏移呈负相关（r = -0.52，p<0.02），表明快速的手臂运动与改善的平衡控制相关。回归分析证实手臂外展加速度是侧向CoM位移的重要预测指标（p = 0.005），这意味着在滑倒期间，手臂加速度每增加1000度/秒，侧向CoM位移大约减少2厘米。这些发现表明，老年人在滑倒时手臂加速度的降低可能会损害他们有效稳定CoM的能力，突出了预防跌倒干预的一个可能目标。
