Table 4. Parameters of joint spring-mass model during vertical jumping. Data are means (±SD). Young Group Older Group Hip Normalized Mhip-minimally (Nm·kg-1) 2.40 (.39) 1.71 (.39) * ∆θhip (degree) 94.91 (12.81) 74.87 (15.08) * Normalized khip (Nm·kg-1·degree-1) .03 (.00) .02 (.00) Knee Normalized Mknee-minimally (Nm·kg-1) 1.48 (.15) .78 (.28) * ∆θknee (degree) 95.21 (8.34) 88.62 (13.57) Normalized kknee (Nm·kg-1·degree-1) .02 (.00) .01 (.00) * Ankle Normalized Mankle-minimally (Nm·kg-1) 1.71 (.22) 1.46 (.20) ∆θankle (degree) 37.18 (1.35) 32.26 (7.51) Normalized kankle (Nm·kg-1·degree-1) .05 (.01) .05 (.02) * significant difference between groups, p < 0 .05.