This training is about mastering the forward lean. An effective forward lean occurs from the hips while keeping the spine straight. Effectively leaning from the hips has been shown to decrease the stress on your knees. A good lean shifts our center of mass forward, decreasing the bending force (torque) at the knee. With decreased bending force comes less quad force to control the applied torque. The result is less compression force between your knee cap (patella) and the thigh bone (femur). If you can lean properly from the hips, you’ll leverage gravity to provide a propulsive force. A controlled fall forward initiated by gravity will use no additional muscular energy, which translates to faster splits without burning more calories.
