Simple equations to predict concentric lower body muscle power in older adults using a 20-second chair-rise test

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)



First Committee Member

Joseph Signorile - Committee Chair


Background. Muscle power is an important factor affecting independence in older adults. Unfortunately, there is no inexpensive, easy to perform, and convenient test that can quantify power in this population in an examination room or clinical office setting. Therefore, we constructed an equation to predict power in older persons using chair rises. Methods. 14 community-dwelling older adults, aged 76 +/- 7.19, performed the 30s chair-rise test at maximal speed. Average (AP) and peak (PP) power values were computed during the test using force platform and high-speed motion analysis data. Results. Since all subjects completed 20s of the test, we constructed multivariate linear regression equations to predict AP and PP using the number of rises performed in 20s, subject's gender, body mass and femur length. Femur length and gender did not contribute significantly to the model (R2 values = 0.01 and 0.00, respectively). Therefore, body mass and the chair rises achieved in 20s were used as independent variables in a regression model to predict power. Predicted values computed using these equations were significantly correlated with values computed in the laboratory (AP: R = 0.89; PP: R = 0.90; p < 0.01). Conclusion . These data indicate that a simple chair rise test, which can be performed in virtually any setting, can be used to predict lower body muscle power in older persons. This may serve as a useful clinical tool for detecting physical vulnerability and fall-risk in this population.


Health Sciences, Recreation

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