The structure underlying physical performance measures for older adults in the community

A 6-item physical performance test assessing hand strength/speed, mobility, and balance was administered to 678 elderly people from a Japanese community (age 65-89). A second-order covariance structure model applied to the data revealed that three factors in observed variables (Hand Power, Walking, and Balance) had loadings more than 0.8 on a single higher-order factor, Basic Motor Ability (BMA). The BMA score, or "Physical Performance Age (PPA)", of the individual was calculated on the basis of this model as a unidimensional summary score of physical performances. The PPA predicted the self-reported levels of competence and physical activity with greater accuracy than age alone. The PPA also differentiated those at the high end of the functional spectrum, and thereby not identifiable by use of ordinary self-reported functional measures. The results suggest that a short physical performance battery assessing physical functioning is useful in community-based studies of aging.