Is there a relationship between balance, gait performance and muscular strength in 75-year-old women?

OBJECTIVE To see if there is a relationship between clinical and laboratory tests of balance, muscular strength and gait in elderly women. DESIGN A randomized population-based study. SETTINGS Malmö, Sweden. METHODS We investigated balance with a simple test of standing on one leg, as well as a computerized balance platform. Muscular strength was tested by computerized dynamometer. Extension and flexion of the knee and dorsiflexion of the ankle were tested. We measured the time and number of steps taken to walk a certain distance and the subjects' height and weight. PARTICIPANTS 418 randomly selected 75-year-old women, of whom 230 took part. RESULTS There was no relation between the computerized balance tests and any of the other tests. The non-computerized balance test was correlated with gait time and number of steps (r = -0.50, P<0.001 and r = -0.40, P<0.001, respectively). Tests of extension and flexion, strength of the knee and ankle dorsiflexion were related to gait, speed and number of steps. Heavy women had poorer balance when assessed by the non-computerized test (r = -0.32, P<0.001) and with the computerized, stable platform, eyes-open test (r = 0.27, P<0.001) and eyes-closed test (r = 0.44, P<0.001). The heavier an individual was, the slower her gait and the shorter her steps, despite having stronger knee muscles. CONCLUSION There is no relationship between the simple balance tests and computerized platform tests. Muscle strength of the leg is not necessarily linked to balance, but rather to gait performance.