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

Abstract

Bischoff HA, Conzelmann M, Lindemann D, Singer-Lindpaintner L, Stucki G, Vonthein R, Dick W, Theiler R, Stähelin HB. Self-reported exercise before age 40: influence on quantitative skeletal ultrasound and fall risk in the elderly. Arch Phys Med Rehabil 2001;82:801-6. Objectives: To compare musculoskeletal factors with bone structure, as measured 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 mobility; functional reach test, for balance), and 3 muscle strength tests (knee flexor, knee extensor, grip). Falls were monitored prospectively in a subgroup of 94 mobile subjects of 1 geriatric hospital throughout each individual length of stay (median, 31.4wk: interquartile range, 16-56.4wk). Main Outcome Measurements: Functional and strength tests, mobility status, and self-reported exercise before age 40 were musculoskeletal factors to be 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; knee extensor: r =.30) and functional tests (TUG: r = −.25; functional reach: r =.16). Women who reported regular exercise before age 40 had higher QUS (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 combination 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 calcaneus. In addition, a beneficial effect of former exercise on QUS and fall risk at advanced age could be documented in women. Both findings support life-long engagement in exercise, which might be particularly meaningful for women.