Factors that modify the association between knee pain and mobility limitation in older women: the Women's Health and Aging Study
- S E Lamba,
- J M Guralnikb,
- D M Buchnerc,
- L M Ferruccid,
- M C Hochberge,
- E M Simonsickb,
- L P Fried for the Women's Health and Aging Studye
- aSchool of Health and Social Sciences, Coventry University, Priory Street, Coventry CV1 5FB, UK, bEpidemiology, Demography, and Biometry Program, National Institute of Aging, Bethesda, Maryland, USA, cDepartment of Health Sciences, University of Washington, Seattle, USA, dGeriatric Department, “I Fracticini”, National Research Institute (INRCA), Florence, Italy, eDepartment of Medicine and Epidemiology, School of Medicine, Johns Hopkins Medical Institutions, Baltimore, USA
- Professor Lamb Email:s.lamb{at}coventry.ac.uk
- Accepted 29 November 1999
Abstract
OBJECTIVE To investigate the influence of pain severity, knee extensor muscle weakness, obesity, depression, and activity on the association between recent knee pain and limitation of usual and fast paced walking, and ability to rise from a chair.
METHODS A cross sectional analysis of 769 older women (mean age 77.8, range 65–101) with physical disability, but no severe cognitive impairment. Severity of knee pain in the past month was classified as none, moderate, or severe. Mobility was measured using timed performance tests.
RESULTS The prevalence of recent knee pain was 53% (408/769). One third of the women with pain reported it to be severe. In general, knee pain was only significantly associated with limited mobility if severe. Obesity, activity and, to a lesser extent, depression intensified the effects of pain. Knee extensor weakness did not. Obesity was a distinctive risk factor in that it substantially increased the risk of mobility limitation, but only in women with pain. In women who had severe pain, activity (walking more than three city blocks in the past week) increased the risk of walking disability more than inactivity. Depression had a minor, but statistically significant effect on walking ability, but not the ability to rise from a chair.
CONCLUSION In older women with recent knee pain, a high pain severity score, obesity, and activity are important factors that increase the risk of mobility limitation.
Footnotes
-
This analysis was completed when Sarah Lamb was a Harkness Fellow of the Commonwealth Fund of New York, and a visiting scientist at the Epidemiology, Biometry, and Demography Program of the National Institute of Aging, USA.
