Background/Purpose: While lower extremity function is thought to affect mobility, little is known of the influence of foot structure or function uponmobilitylimitations.Weevaluatedtheassociationsoffootstructureand footfunctionwithmobilitylimitationsincommunity-dwellingoldermenand women. Methods: FraminghamFootStudyparticipants(2002–2008)withperfor- mance measures of mobility limitations were included in this cross-sectional analysis. Mobility limitations was assessed using the Short Physical Perfor- mance Battery (SPPB), a composite of 3 timed performance tests (4-meter walk (s), chair stands (s), and balance test) with each test scored on a scale of 0 to 4 (total score range 0–12, higher score better function). Previously, SPPBscoreshavepredictedphysicallimitations,disabilityandmortality.We dichotomizedSPPBas1–9toindicatemobilitylimitationsand10–12asgood mobility. We also examined quartiles of chair stand and walk time. Foot function while walking (pronated, supinated, normal) and weight-bearing archstructure(low,high,normalarch)weredefinedusingaTekscanmatscan pressuresystem.Age,sex,bodymassindex(BMI;30, 30kg/m2),current smoker (y/n) and depression (CES-D scale) were also obtained. Sex-specific multivariate logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for the association between foot structure and function with mobility limitations, adjusting for factors above. Results:In556menand700women,averageagewas70yrs(10.8)and BMIwas28(5.2).16%hadmobilitylimitations,30%hadhigharchedand 27%hadlowarchedfootstructure;33%hadpronatedand27%hadsupinated foot function. Foot function was not associated with mobility limitations. In womenonly,lowarchedfootstructurewasassociatedwithincreasedoddsof mobility limitations (SPPB; OR2.27, p0.005) after adjustment (Table). No associations were seen between foot structure or function and chair stand time (ORs 0.8–1.1, all p 0.4). In quartiles of walk time, men in the 3rd quartile, compared to the lowest (fastest), were less likely to have a high arch foot structure (OR0.53) and supinated foot function (OR0.51). Women with a low arched foot were less likely to be in the 4th quartile (slowest walkers) compared to the fastest walkers and women with a pronated foot functionweremorelikelytobeinthe3rd quartileofwalkingspeedcompared to the fastest walkers. Conclusion: Specific components of foot structure and function were associated with mobility limitations in our study, albeit with inconsistent patterns between men and women. Given these results, future work might examinespecificregionsoffootpressuresandtime-integralmeasuresinorder to drill down to biomechanical mechanisms.
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