Association between maximal lower leg strength and static and dynamic balance as well as gait velocity in older adults.

PURPOSE: Falls cause serious injuries with partially long immobilization time and decreased quality of life in older adults. The risk factors comprise instability in gait and balance, which were moderately correlated with the strength capacity. While the literature focused on upper-limb strength, in this work, we sought to evaluate the relationship between maximal plantar flexion and dorsiflexion strength and walking and balance parameters in older adults.

METHODS: A total of 51 healthy and active participants (age: 78.5 ± 5.8 years) participated in the study. Lower-leg maximal strength was determined isometrically. Selected gait parameters (normal and maximal walking velocity), static balance [center of pressure (CoP) sway in different standing conditions], and the timed up and go (TUG) and sit-to-stand (STS) were determined. Correlations [Pearson (rp)/Spearman (rs)] were calculated in general and stratified by sex.

RESULTS: Walking velocity, STS, and TUG were significantly influenced by lower-leg strength (rs up to 0.79 in males). Static balance showed no meaningful relationships. In general, fewer correlations in female participants reached the level of significance and showed smaller effect sizes.

DISCUSSION: Although smaller sex-subgroup sample sizes might limit confidence in the results, male participants showed higher correlations between strength and walking velocity (up to rs = 0.79) and individual balance parameters (rs = 0.77) than female participants (rs = 0.56 for gait, rs = 0.72 for TUG). The results align with previous studies showing a potential influence of strength on gait parameters; however, a causal relationship must be confirmed by longitudinal study designs. Nevertheless, based on the results, there is a need for future sex-specific studies on the necessity of sex-specific balance and fall-prevention routines.