Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 54, Issue 4 M172-M176, Copyright © 1999 by The Gerontological Society of America

JOURNAL ARTICLE

Coimpairments: strength and balance as predictors of severe walking disability

T Rantanen, JM Guralnik, L Ferrucci, S Leveille and LP Fried
Epidemiology, Demography and Biometry Program, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA. taina@maila.jyu.fi

BACKGROUND: Little information is available on the joint effects of multiple impairments (coimpairments) on the risk of disability. Our aim was to study the joint effects of strength and balance impairments on severe walking disability. METHODS: The data are from the baseline of the Women's Health and Aging Study (WHAS), a study of moderately to severely disabled women. A total of 1,002 women aged 65 and older participated in the tests, which took place in their homes. Severe walking disability was defined as self-reported inability to walk one- quarter mile and customary walking speed in a 4-meter test of < or =0.4 m/s. Balance was measured as an ability to hold progressively more difficult stands (feet side-by-side, semitandem and tandem stands). Maximal knee extension strength was measured using a hand-held dynamometer. RESULTS: There were 129 women who were severely walking disabled but able to walk at least minimally. In logistic regression analysis, balance and knee extension strength were independent predictors of severe walking disability. To study the combined effects, nine groups were formed on the basis of strength tertiles by balance categories in the entire population. In the best balance category, the crude prevalences of severe walking disability were 1.2%, 4.9%, and 14.3% in the highest to lowest strength tertiles. In the middle balance category, the rates were 2.9%, 10.0%, and 45.4.1%, and in the poorest balance category 4.9%, 22.1%, and 42.6%, correspondingly. The age, body weight, and height-adjusted odds ratios (OR) showed that the risk of severe walking disability in the subgroup with best balance and strength was less than 5% of the risk in the subgroup with poorest balance and strength (OR .034, 95% confidence interval [CI] .007-.166). Correspondingly, in the subgroups with poorest strength and best balance (OR .097, 95% CI .025-.38) or poorest balance and best strength (OR .102, 95% CI .012-.866) the risk was about 10%. The age-specific estimates of prevalence of severe walking disability in women were: 2.0% for ages 65-74 years, 3.4% for ages 75-84 years, and 9.1% for ages 85 years and older. CONCLUSIONS: The burden of coimpairments seems to be greater than the sum of single impairments involved. An effective way to reduce severe disabilities could be prevention of coimpairments.

This article has been cited by other articles:

				M. L Puthoff and D. H Nielsen Relationships Among Impairments in Lower-Extremity Strength and Power, Functional Limitations, and Disability in Older Adults Physical Therapy, October 1, 2007; 87(10): 1334 - 1347. [Abstract] [Full Text] [PDF]

				S. Stenholm, P. Sainio, T. Rantanen, S. Koskinen, A. Jula, M. Heliovaara, and A. Aromaa High Body Mass Index and Physical Impairments as Predictors of Walking Limitation 22 Years Later in Adult Finns J. Gerontol. A Biol. Sci. Med. Sci., August 1, 2007; 62(8): 859 - 865. [Abstract] [Full Text] [PDF]

				N. K LeBrasseur, S. P Sayers, M. M Ouellette, and R. A Fielding Muscle Impairments and Behavioral Factors Mediate Functional Limitations and Disability Following Stroke Physical Therapy, October 1, 2006; 86(10): 1342 - 1350. [Abstract] [Full Text] [PDF]

				G. F. Martel, S. M. Roth, F. M. Ivey, J. T. Lemmer, B. L. Tracy, D. E. Hurlbut, E. J. Metter, B. F. Hurley, and M. A. Rogers Age and sex affect human muscle fibre adaptations to heavy-resistance strength training Exp Physiol, March 1, 2006; 91(2): 457 - 464. [Abstract] [Full Text] [PDF]

				M. J. Delmonico, M. C. Kostek, N. A. Doldo, B. D. Hand, J. A. Bailey, K. M. Rabon-Stith, J. M. Conway, C. R. Carignan, J. Lang, and B. F. Hurley Effects of moderate-velocity strength training on peak muscle power and movement velocity: do women respond differently than men? J Appl Physiol, November 1, 2005; 99(5): 1712 - 1718. [Abstract] [Full Text] [PDF]

				D. Melzer, M. G. Dik, G. J. van Kamp, C. Jonker, and D. J. Deeg The Apolipoprotein E e4 Polymorphism Is Strongly Associated With Poor Mobility Performance Test Results But Not Self-Reported Limitation in Older People J. Gerontol. A Biol. Sci. Med. Sci., October 1, 2005; 60(10): 1319 - 1323. [Abstract] [Full Text] [PDF]

				A. L Harrison The Influence of Pathology, Pain, Balance, and Self-efficacy on Function in Women With Osteoarthritis of the Knee Physical Therapy, September 1, 2004; 84(9): 822 - 831. [Abstract] [Full Text] [PDF]

				J. F. Bean, S. G. Leveille, D. K. Kiely, S. Bandinelli, J. M. Guralnik, and L. Ferrucci A Comparison of Leg Power and Leg Strength Within the InCHIANTI Study: Which Influences Mobility More? J. Gerontol. A Biol. Sci. Med. Sci., August 1, 2003; 58(8): M728 - 733. [Abstract] [Full Text] [PDF]

				J. E. Morley Editorial: Citations, Impact Factor, and the Journal J. Gerontol. A Biol. Sci. Med. Sci., December 1, 2002; 57(12): M765 - 769. [Full Text] [PDF]

				S.M. Roth, G.F. Martel, F.M. Ivey, J.T. Lemmer, B.L. Tracy, E.J. Metter, B.F. Hurley, and M.A. Rogers Skeletal Muscle Satellite Cell Characteristics in Young and Older Men and Women After Heavy Resistance Strength Training J. Gerontol. A Biol. Sci. Med. Sci., June 1, 2001; 56(6): B240 - B247. [Abstract] [Full Text] [PDF]