HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Marsh, A. P. Articles by Ferrucci, L. Search for Related Content PubMed PubMed Citation Articles by Marsh, A. P. Articles by Ferrucci, L.

Lower Extremity Strength and Power Are Associated With 400-Meter Walk Time in Older Adults: The InCHIANTI Study

¹ Department of Health and Exercise Science, Wake Forest University, Winston-Salem, North Carolina.
² Section on Biostatistics, Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina.
³ Florence Local Health Unit and the Tuscany Regional Health Agency, Florence, Italy.
⁴ Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, Maryland.
⁵ Longitudinal Studies Section, Clinical Research Branch, National Institute on Aging, Baltimore, Maryland.

Address correspondence to Anthony P. Marsh, Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC 27109-7868. E-mail: marshap{at}wfu.edu or Michael E. Miller, Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1063. E-mail: mmiller{at}wfubmc.edu

Background. It has been suggested that lower extremity muscle power is more important for physical function in older adults compared to strength, and that there is a nonlinear relationship between power or strength and physical function that might be indicative of a threshold above which the association between muscle function and physical function is no longer evident. This study examined the association between lower extremity strength or power with the time to complete a 400-meter walk, and attempted to identify thresholds within the relationship.

Methods. A cross-sectional analysis of a sample of 384 females and 336 males aged 65 years from the InCHIANTI study ("Invecchiare in Chianti," i.e., Aging in the Chianti Area) was conducted. Measures included 400-meter walk time, lower extremity strength and power, comorbidities, and sociodemographic variables (age, gender, height, education, cognitive function, depression).

Results. Linear regression models showed that both lower extremity strength and power were significant predictors of 400-meter walk time, although power explained marginally more of the variance in 400-meter walk time. Quadratic models of lower extremity strength and power fit the data slightly better than the linear models. Regardless of gender, comorbidities, or normalization scheme for strength and power, the curvilinear form of the relationship between strength or power and 400-meter walk time remained the same.

Conclusions. Lower extremity muscle strength and power are both important predictors of the 400-meter walk time. Although curvilinear relationships existed between muscle strength and power and the 400-meter walk time, the data do not indicate a clear threshold for either strength or power above which the performance in the 400-meter walk test plateaus.

This article has been cited by other articles:

				F. Lauretani, R. D. Semba, S. Bandinelli, M. Dayhoff-Brannigan, V. Giacomini, A. M. Corsi, J. M. Guralnik, and L. Ferrucci Low Plasma Carotenoids and Skeletal Muscle Strength Decline Over 6 Years J. Gerontol. A Biol. Sci. Med. Sci., April 1, 2008; 63(4): 376 - 383. [Abstract] [Full Text] [PDF]

				F. Lauretani, R. D Semba, S. Bandinelli, A. L Ray, J. M Guralnik, and L. Ferrucci Association of low plasma selenium concentrations with poor muscle strength in older community-dwelling adults: the InCHIANTI Study Am. J. Clinical Nutrition, August 1, 2007; 86(2): 347 - 352. [Abstract] [Full Text] [PDF]