Self-reported exercise before age 40: Influence on quantitative skeletal ultrasound and fall risk in the elderly

Objectives: To compare musculoskeletal factors with bone structure, as meas ured by quantitative ultrasound (QUS) at the calcaneus, and their potential to predict fall risk in geriatric inpatients. Design: Longitudinal. Setting: Two geriatric hospitals in Switzerland. Participants: A total of 134 of 207 long-stay geriatric patients (96 women, 38 men) who were able to perform the timed up and go (TUG) test. Interventions: Five musculoskeletal tests: 2 functional tests (TUG, for mob ility; functional reach test, for balance), and 3 muscle strength tests (kn ee flexor, knee extensor, grip). Falls were monitored prospectively in a su bgroup of 94 mobile subjects of 1 geriatric hospital throughout each indivi dual length of stay (median, 31.4wk: interquartile range, 16-56.4wk). Main Outcome Measurements: Functional and strength tests, mobility status, acid self-reported exercise before age 40 were musculoskeletal factors to b e compared with QUS. Results: QUS was higher in mobile subjects without walking aid (p < .0001) and correlated significantly with muscle strength (knee flexor: r = .36; kn ee extensor: r = .30) and functional tests (TUG: r = -.25; functional reach : r = .16). Women who reported regular exercise before age 40 had higher QU S (p = .01) and fewer falls (p = .01). Falls were less frequent in subjects with walking aid (p = .03). No single musculoskeletal test, but rather a c ombination of demographic variables, musculoskeletal factors, and QUS could predict 76% of total variation of fall risk. Conclusion: This study showed the important impact of current mobility and muscle strength status on bone structure, as measured by QUS at the calcane us. In addition, a beneficial effect of former exercise on QUS and fall ris k at advanced age could be documented in women. Both findings support lifel ong engagement in exercise, which might be particularly meaningful for wome n. (C) 2001 by the American Congress of Rehabilitation Medicine and the Americ an Academy of Physical Medicine and Rehabilitation.