During functional tasks such as walking, there is a disturbance of postural stability, which can result in falls, which bring functional impairment to the older adults. It is attributed that muscle strength can contribute to postural stability in gait, but it is unclear which muscle groups contribute most to postural stability in gait when it is assessed using the Functional Gait Assessment (FGA).

The purpose of the study was to investigate whether handgrip, trunk extensor, hip extensor and abductor, knee extensor, and plantar flexor muscle strengths are related to postural stability in gait in community-dwelling older adults people assessed using the FGA.

A cross-sectional observational study with community-dwelling older adults (60 years or older) of both sexes, with independent gait and recruited by convenience. Muscle strength (maximum isometric contraction) of handgrip (Jamar dynamometer), trunk extensors, hip extensors and abductors, knee extensors and plantar flexors, normalized by body weight (microFET2 hand dynamometer) on the dominant side was evaluated. Postural stability during gait was assessed by the Functional Gait Assessment (FGA) scale. Pearson (r) and Spearman (rho) analyses were used to verify the correlation between variables considering data distribution. The significance level was set at 5%.

Sixty-six older adults subjects were evaluated with a mean age of 73.70 (±7.8) years. The descriptive characteristics of the sample were mean ± standard deviation: FGA (21.71 ± 5.37) score, grip strength (21.56 ± 8.43 kilogram-force), muscle strength of trunk extensors (2.32 ± 0.93 Newton/weight), hip extensors (1.10 ± 0.56 Newton/weight), hip abductors (2.27 ± 0.87 Newton/weight), knee extensors (2.56 ± 1.18 Newton/weight) and plantar flexors (3.22 ± 1.52 Newton/weight). All muscle strength variables showed moderate and positive correlation with postural stability in gait, being palmar grip strength (p= 0.001, r=0.43), trunk extensor muscle strength (p= 0. 001, r=0.50), hip extensors (p=0.001, rho= 0.56), hip abductors (p=0.001, r=0.51), knee extensors (p= 0.001, rho=0.56) and plantar flexors (p=0.001, rho=0.44).

According to the results, the higher the muscle strength parameters, the greater the postural stability during gait. Thus, muscular strength should be evaluated in this population as a modifiable factor, and the continuity of the study with an increased sample is necessary to confirm the results.

From the results, we highlight the importance of the relationship between muscle strength and postural stability in the gait of community-dwelling older adults when it is assessed by a reliable and valid instrument. Future studies need to investigate whether changes in muscle strength can generate improvements in postural stability when it is assessed by FGA.