Functional fitness tests and their association with upper-limb isokinetic strength in older adults

PURPOSE: This study investigated the association between commonly used functional fitness tests (i.e., Up-and-Go Test [UGT], 30-Second Chair Stand Test [30CS], 30-Second Arm Curl Test [30AC], and 6-Minute Walk Test [6MWT]) and upper-limb isokinetc strength (elbow and shoulder flexion-extension isokinetic absolute and relative strength at 60º/s and 180º/s) in older adults. It was hypothesized that upper-limb-specific tests would show stronger associations, that elbow strength would be better explained than shoulder strength, and that higher angular velocities would demonstrate stronger associations. METHODS: Three hundred and twenty-seven apparently healthy older adults (247 women and 80 men; age: 69.27 ± 5.62) enrolled in this cross-sectional study. Isokinetic concentric strength was assessed before functional fitness tests. RESULTS: = 0.12-0.42). No consistent pattern of stronger associations at higher angular velocities was identified. CONCLUSIONS: Upper-limb isokinetic strength is associated with functional fitness in older adults, although associations were generally small to moderate. Functional fitness, together with age and sex, explained up to 55% of the variance. These findings suggest that functional fitness tests may provide indirect and complementary information related to upper-limb strength in settings where isokinetic dynamometry is not available, but they should not be considered surrogate measures of muscle strength.