ABSTRACT
BACKGROUND: Understanding of the influence of trunk muscles on the older adult's limit of stability (LOS) is important for clinical practice. OBJECTIVE: To compare the anterior and posterior LOS and the flexor and extensor trunk muscle function; verify the association of trunk muscles and LOS, and the association of LOS and the previous falls of community-dwelling older adults. METHODS: Sample characterization data, trunk muscle function (peak torque - PT and torque steadiness - TS), LOS and previous falls (6 months) were collected from 79 older people. Comparisons were made between the variables of the anterior/posterior LOS (Reaction time, Movement velocity, Maximum excursion, Directional control), between trunk extensors/flexors muscle function and between TS at 10% and at 50%. Associations were made between the anterior/posterior LOS and the number of previous falls and between LOS and trunk muscle function. RESULTS: The posterior LOS was worse than the anterior LOS, except for the reaction time. The flexor muscles obtained a lower PT, but better performance in TS. The TS at 10% of the trunk extensor was associated with the posterior directional control (p = 0.032). There was no association between trunk muscle function and the anterior LOS, or between previous falls and LOS. CONCLUSIONS: The older adults presented worse performance in the posterior LOS and worse TS in the trunk extensor muscles, although the trunk extensor muscles presented a higher PT. Although no association between LOS and previous falls, the better the TS at 10% of the trunk extensors, better posterior directional control.
