Commonly measured constructs of mobility included walking , climbing stairs , and lower extremity function .
There was heterogeneity in ways of defining and measuring mobility limitation in older adults living in the community .
Mobility is critical in maintaining independence in older adults .
This study aims to systematic ally review the scientific literature to identify measures of mobility limitation for community-dwelling older adults .
Knee extension strength cutpoints for maintaining mobility.
OBJECTIVES To identify levels of knee extensor strength that are associated with high and low risk of incident  severe mobility limitation ( SML ) in initially well-functioning older adults . DESIGN Prospect i ve cohort study . SETTING University clinic center . PARTICIPANTS One thous and three hundred fifty-five men and 1,429 women ( aged 73.6+/-2.85 ) who reported no mobility limitation . MEASUREMENTS Unilateral knee extensor isokinetic strength of participants was obtained . Participants were followed over a median of 5.90 years for the onset of SML , defined as two consecutive reports of a lot of difficulty or inability to walk one-quarter of a mile or climb 10 steps . Deciles of knee extension strength relative to body weight were evaluated to identify cutpoints most predictive of incident SML . Cutpoints were then compared with prevalence of having slow gait speed ( < 1.22 m/s ) and mortality . RESULTS Two sex-specific knee extension strength cutpoints were found . High and low risk of SML corresponded to less than 1.13 newton-meters (Nm)/kg ( 1st decile ) and more than 1.71 Nm/kg ( 6th decile ) in men and less than 1.01 Nm/kg ( 3rd decile ) and more than 1.34 Nm/kg ( 7th decile ) in women , respectively . Moderate risk was defined as being between the low- and high-risk cutpoints . Individuals with knee extension strength in the high- and moderate-risk categories were more likely to have a gait speed less than 1.22 m/s ( hazard ratio (HR)=7.00 , 95 % confidence interval (CI)=5.47 - 8.96 and HR=2.14 7.00 , 95 % CI=1.73 - 2.64 , respectively ) and had a higher risk of death ( HR=1.77 , 95 % CI=1.41 - 2.23 and HR=1.51 , 95 % CI=1.24 - 1.84 , respectively ) than individuals in the low-risk category . Adjustment for demographic factors , health behaviors , and medical conditions did not alter these associations . CONCLUSION Knee extensor strength cutpoints provide objective markers to identify initially well-functioning older adults at high and low risk of future mobility limitation
Commonly measured constructs of mobility included walking , climbing stairs , and lower extremity function .
There was heterogeneity in ways of defining and measuring mobility limitation in older adults living in the community .
Mobility is critical in maintaining independence in older adults .
This study aims to systematic ally review the scientific literature to identify measures of mobility limitation for community-dwelling older adults .