Figure 1

Schematic graph for definition of the power components P1-P4 contributing toward total power (Power) during a crank revolution. The first power component (P1) represents concentric knee extensor and eccentric hip flexor power; the second component (P2) represents concentric hip extensor and eccentric knee flexor power; the third component (P3) represents concentric knee flexor and eccentric hip extensor power, and the fourth component (P4) represents concentric hip flexor and eccentric knee extensor power. The knee (dashed), the hip (dashed-dotted) and the net power (continuous thin) are shown. Concentric and eccentric powers are positive and negative, respectively.