Fig. 4. Mean power and work produced during steady speed (gray) and jumping (black) trials. (A) Power output during stance normalized to body mass (left y axis) and hind limb extensor muscle mass (right y axis). Horizontal broken lines represent the mean power produced during stance. (B) Negative (–), positive (+) and net (patterned bars) muscle mass-specific work produced during stance. Dotted lines (A) and error bars (B) indicate S.E.M.