Biomechanical determinants of maximal stair climbing capacity in healthy elderly women

Stair walking is an important functional movement task that may require considerable amounts of muscle strength/power. This study aimed to perform a descriptive biomechanical analysis of maximal stair ascent in elderly women and to examine the relationship between mechanical muscle function and maximal stair ascending velocity (MAV). Seventeen healthy elderly women (age 72.4 +/- 6.4) were tested for MAV, maximal multi-joint counter movement jumping (CMJ), and maximal single-joint isokinetic/isometric muscle moment. Peak knee joint power during MAV was the single independent parameter that explained most of the variation in MAV (50%), however, combining knee and ankle parameters in a multiple regression analysis mean joint power explained 82.4% of the variation in MAV. Generally, multi-joint CMJ parameters showed stronger correlations with MAV than single-joint isokinetic/isometric muscle strength parameters. MAV appeared to be highly dependent upon knee and ankle power and to a lesser extent on joint moment and range of motion. Furthermore, CMJ assessment seemed well applicable in healthy elderly individuals to distinguish between differentiated levels of maximal stair walking capacity.