“…We have not, however, found a social gradient in grip strength after controlling for covariates. Our findings are generally in agreement with many previous studies showing that educational level plays an important role in PF, mobility, disability, and cognitive decline in aging populations (Callahan & Pincus, 1988;Coppin, Shumway-Cook, et al, 2006;Patel et al, 2006;Groffen, Bosma, Van Den Akker, Kempen, & Van Eijk, 2008;Rantanen, Parkatti, & Heikkinen, 1992). The similarity of results on chair rise and walk speed, and their correlation, is also not surprising as both tests measure lower limb muscle strength (Steffen et al, 2002).…”