Sensorimotor function, balance abilities and pain influence Timed Up and Go performance in older community-living people

Abstract

The Timed up and Go Test (TUG) is recommended as a screening tool for fall risk in older people. It is assumed that this general mobility test is underpinned by physiological factors such as strength, coordination and balance. However, no studies have examined the range of physiological and psychological factors which influence performance on this test. The aim of this study was to examine the relative contributions of a range of sensorimotor, balance and psychological factors to TUG performance in a large sample of older people. 280 community-dwelling people aged 65 plus years (mean age 74.9, SD=6.4) underwent the TUG test, as well as quantitative tests of vision, peripheral sensation, strength, reaction time, balance, fear of falling, pain and vitality. The time required to complete the TUG was significantly related to limitations in instrumental activities of daily living and fear of falling. Many physiological and psychological factors were significantly associated with TUG performance in univariate analyses. Stepwise multiple regression analyses identified knee strength, postural sway, reaction time, edge contrast sensitivity, MMSE score, SF12 body pain and general health scores, number of medical conditions and age as significant and independent predictors of TUG performance. Of these measures, the lower limb strength measure explained most variance in TUG times. However, other sensorimotor, balance, psychological and health measures provided important independent information. The combined set of variables explained 43.5% of the variance in TUG times (multiple r=0.65). Findings indicate that, in community-dwelling older people, TUG performance is influenced by lower limb strength, balance, reaction time, vision and pain, in addition to cognitive function and health status.