Fig. 1. Joint kinematics (A) and joint torque patterns (B) during a maximal-effort jump in Rana pipiens. (A) The joint angle changes during the take-off phase of jumping (when the feet are in contact with the ground) are shown. In each panel, the y axis (joint angle) has the same range of 160°. (B) The net torques due to the combination of active muscle forces, passive forces in connective tissues and forces arising from interaction between the metatarsal segment and the ground (see Materials and methods). In each panel, the y axis (torque) has a range of 0.8 N cm. The joint degrees of freedom (DOFs) illustrated are: extensor DOF of the hip (Hip ext.), extensor DOF of the knee (Knee ext.), extensor DOF of the ankle (Ankle ext.), adduction DOF of the hip (Hip add.), external rotation DOF of the hip (Hip rot.), adduction DOF of the knee (Knee add.), external rotation DOF of the knee (Knee rot.) and the iliosacral joint.