Fig. 5. Lateral view of the displacements of the COM, from touchdown (red circle) until the COM is situated 1 cm above the ground surface (body contact), resulting from the simulations of the spring-dashpot model. The time difference between two circles is 0.005 s. (A) A simulation for the real sequence, where the arm angle at touchdown is 125°, resulting in the spring-dashpot becoming shorter and rotating to a vertical position during landing. (B) The arms are put further forward, at an angle of 140°, which results in the arms stretched forward at the moment of body contact. (C) When the arm angle is decreased to 110°, the arms rotate over the vertical position during landing and the frog will land with its front limbs stretched backwards.