Abstract:

OBJECTIVE: A large number of studies have confirmed that lower limb resistance training has a significant effect on increasing skeletal muscle content and reducing the incidence of myopenia in the elderly. At present, there is a great controversy about whether lower limb resistance training can have a positive impact on the walking ability and balance ability of the elderly. Therefore, this Meta-analysis focuses on the intervention effect of lower limb resistance training on walking ability and balance ability of the elderly, so as to provide a theoretical basis for the formulation of standardized exercise prescription for the elderly.

METHODS: A computer-based search was conducted in the English databases of Cochrane Library, PubMed, Web of Science, EBSCO Host, and the Chinese databases of WanFang and CNKI. Randomized controlled trials addressing the effect of lower limb resistance training on walking ability and balance ability in the elderly were collected. Two researchers independently evaluated the methodological quality of the included articles according to the Cochrane system evaluation manual, and extracted the main outcome indicators, including time up-and-go (TUG) test, routine walking speed, functional extension test (FET), one-leg stand with eyes open (OLSO) test, and secondary outcome index, maximum walking speed. The included articles were analyzed using RevMan 5.3 software for a Meta-analysis. 
RESULTS: Fourteen randomized controlled trials were finally included. After the quality evaluation, except for selective reports and other bias risks that were unclear, the overall quality of the articles included was good. A total of 551 subjects were included in these 14 trials, including 285 in experimental group and 266 in the control group. Compared with the control group, lower limb resistance training could significantly improve the TUG time of the elderly under 80 years old [for 60-69 years old, mean difference (MD)=-0.99, 95% confidence interval: -1.90 to -0.08, P < 0.05; for 70-79 years old, MD=-1.17, 95%CI: -2.50  to -0.08, P < 0.01], OLSO time (MD=3.92, 95%CI: 2.46 to 5.38, P < 0.01], FET distance (MD=4.85, 95%CI: 1.93 to 6.63, P < 0.01], and the heterogeneity of TUG time was smaller after more than 12 weeks of training (I2=0). However, the lower limb resistance training had no significant effect on normal walking speed (MD=0.03, 95%CI: -0.05 to 0.10, P=0.46] and maximum walking speed (MD=0.08, 95%CI: -0.02 to 0.17, P=0.11] in all the subjects as well as on TUG time (MD=-4.92, 95%CI: -15.65 to 5.81, P=0.37] in people over 80 years old. 
CONCLUSION: Lower limb resistance training can effectively improve the balance ability of the elderly and the TUG level of the elderly under 80 years old, but there is no significant change in normal walking speed and maximum walking speed. In the future, the formulation of exercise prescription for the elderly should be more standardized and improved and verified. Importantly, the physical characteristics of the elderly at different ages should be distinguished in the formulation of exercise prescriptions, so as to ensure the scientificity and effectiveness of exercise prescriptions in the implementation of different age groups.

Key words: lower limb resistance training, elderly, walking ability, balance ability, speed, walking, extension, stand up, Meta-analysis