Figure 2
From: Role of compliant mechanics and motor control in hopping - from human to robot
Torque-angle relationship in different leg joints in hopping. The graphs for preferred hopping frequency (PHF) and their approximation with a linear relation (dotted line) are shown in the bottom figure. The patterns for four hopping frequencies (75, 100, 125, and 150 % of PHF) in each leg joint are shown in the top graphs. Small circles indicate the touch-down moments.
