The rods allow the motors which move the joints to be placed higher up on the leg, closer to the pivot point that swings the motor. This reduces the torque requ

The rods allow the motors which move the joints to be placed higher up on the leg, closer to the pivot point that swings the motor. This reduces the torque required to move each section of the leg, which in turn allows for smaller motors to be used, which further drives down the torque requirement.