Madigan Michael L, Lloyd Emily M
Department of Engineering Science and Mechanics, Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Blacksburg, VA 24061, USA.
J Gerontol A Biol Sci Med Sci. 2005 Apr;60(4):481-5. doi: 10.1093/gerona/60.4.481.
The purpose of this study was two-fold: 1) to evaluate any age-related differences in peak joint velocities of the stepping limb during single-step recovery from a forward fall, and 2) to determine if the ability to recover from a forward fall with a single step differs when stepping with the dominant or nondominant lower limb (LL).
Ten young (19-23 years old) and ten older (65-83 years old) men were released from forward-leaning positions and attempted to recover their balance with a single step. Lean magnitude was increased until the men failed to recover their balance with a single step. The men performed the experiment twice, once while stepping with the dominant LL and once while stepping with the nondominant LL, to determine if the ability to recover from a forward fall is limb dependent. Peak joint velocities during single-step recoveries were determined.
No age-related differences in peak joint velocities were found during recovery from small lean magnitudes, but older men exhibited slower velocities during recovery from maximum lean magnitudes. There was no difference in the maximum lean magnitude achieved by the men when stepping with the dominant or nondominant LL.
The previously reported age-related reduction in stepping speed seems to be due to localized reductions in maximum hip flexion velocity, knee flexion and extension velocity, and ankle plantar flexion velocity. Also, the ability of young and older men to recover from a forward fall with a single step does not seem to be limb dependent.
本研究的目的有两个:1)评估向前跌倒后单步恢复过程中迈步肢体峰值关节速度的任何年龄相关差异;2)确定用优势下肢或非优势下肢迈步时,单步从向前跌倒中恢复的能力是否存在差异。
让10名年轻男性(19 - 23岁)和10名老年男性(65 - 83岁)从前倾姿势开始,尝试单步恢复平衡。逐渐增加倾斜幅度,直到他们无法单步恢复平衡。这些男性进行两次实验,一次用优势下肢迈步,一次用非优势下肢迈步,以确定从向前跌倒中恢复的能力是否取决于肢体。测定单步恢复过程中的峰值关节速度。
从小倾斜幅度恢复过程中未发现峰值关节速度存在年龄相关差异,但老年男性在从最大倾斜幅度恢复过程中速度较慢。用优势或非优势下肢迈步时,男性达到的最大倾斜幅度没有差异。
先前报道的与年龄相关的步速降低似乎是由于最大髋关节屈曲速度、膝关节屈伸速度和踝关节跖屈速度的局部降低所致。此外,年轻和老年男性单步从向前跌倒中恢复的能力似乎不取决于肢体。