Neuromuscular Research Laboratory, Department of Kinesiology and Health Science, Utah State University, Logan.
Human Performance Laboratory, Department of Kinesiology and Sport Management, Texas Tech University, Lubbock.
J Gerontol A Biol Sci Med Sci. 2018 Apr 17;73(5):603-607. doi: 10.1093/gerona/glx156.
The current understanding of age-related declines in muscle strength capacities is largely based upon strength testing at joint angles of optimal performance, but many activities of daily living involve force generation at muscle lengths/angles outside of optimal force. This study investigated the influence of age, joint angle, and muscle group (knee extensors and flexors) on maximal and rapid strength characteristics. Young (n = 21; age = 22.1 years) and older (23; 72.6 years) adults performed maximal voluntary contractions for the knee extensors and flexors at 20°, 60°, and 90° joint angles. Peak torque (PT) and rate of torque development (RTD) were calculated. An age, angle, and muscle interaction was found for PT, revealing differences for the knee flexors at all three joint angles for the older adults, whereas the young adults were similar between the 20° and 60° angles. The later RTD variable showed an age and muscle group interaction, whereas no interactions were found for early RTD. The angle of strength testing for maximal strength (PT) of the knee flexors showed dissimilar changes in strength characteristics for young versus older adults across joint angles. For later RTD variables, the testing angle was a more prominent factor for the knee extensors, but less so for the flexors.
目前对于与年龄相关的肌肉力量下降的理解在很大程度上基于在最佳表现关节角度下的力量测试，但许多日常生活活动都涉及到肌肉长度/角度超出最佳力的力量产生。本研究调查了年龄、关节角度和肌肉群（膝关节伸肌和屈肌）对最大和快速力量特征的影响。年轻（n = 21；年龄 = 22.1 岁）和年长（23；72.6 岁）成年人在 20°、60°和 90°关节角度下对膝关节伸肌和屈肌进行最大自主收缩。计算峰值扭矩 (PT) 和扭矩发展速率 (RTD)。发现了 PT 的年龄、角度和肌肉相互作用，揭示了在所有三个关节角度下，老年人大腿屈肌的差异，而年轻人在 20°和 60°角度之间相似。后期 RTD 变量显示出年龄和肌肉群的相互作用，而早期 RTD 则没有发现相互作用。对于最大力量（PT）的膝关节屈肌的力量测试角度，年轻人和老年人在关节角度上的力量特征变化不同。对于后期 RTD 变量，对于膝关节伸肌来说，测试角度是一个更为突出的因素，但对于屈肌来说则不然。
