Age and sex differences in the biomechanical and viscoelastic properties of upper limb muscles in middle-aged and older adults: A pilot study
Authors: Meng-Ta Lee 1, Ching-Yi Wu 1, 2, 3, Chiu-Wen Chen 3, Hsien-Lin Cheng 4, Chih-Chi Chen 3, 5, Yu-Wei Hsieh 1, 2, 3
- Department of Occupational Therapy and Graduate Institute of Behavioral Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Linkou, Taiwan
- Division of Occupational Therapy, Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taipei, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
Journal: Journal of Biomechanics - March 2022, Volume 134, Article no. 111002 (DOI: 10.1016/j.jbiomech.2022.111002)
Whether muscle properties gradually change with age and how muscle properties are affected by sex remain unclear. In this study, we investigated the influence of age and sex on the biomechanical and viscoelastic properties of arm muscles in middle-aged and older adults.
In this cross-sectional study, 80 healthy participants were divided by sex (male and female), and each sex group, by 10-year age ranges (40–49, 50–59, 60–69, and 70–79 years). Muscle properties, including tone, stiffness, elasticity, and mechanical stress relaxation time, were measured with the MyotonPRO.
Our results showed that the muscle tone and elasticity of the deltoid and flexor carpi radialis, and the muscle tone of the flexor carpi ulnaris, were significantly greater in men than in women, whereas the stress relaxation time of the triceps was significantly greater in women than in men. Significantly greater muscle stiffness in the biceps brachii was found in the participants over 50 years old. Less muscle elasticity was found in the deltoid, triceps, and flexor carpi ulnaris in those over 70 years old.
In conclusion, age and sex have considerable impacts on upper-limb muscle properties in middle-aged and older adults, which should be taken into consideration when planning health promotion projects.
Keywords: aging, sex, biomechanical properties, viscoelasticity, arm and forearm
Age had a greater effect on muscle stiffness and elasticity, and sex had a greater effect on the muscle tone of upper limb muscles, in the study participants. Further larger-scale studies to investigate the characteristics of muscle properties in patients with neurological and musculoskeletal conditions (e.g., stroke and osteoarthritis) and to compare those parameters in healthy controls and patients with neurological and musculoskeletal conditions are suggested.