How do the bones and muscles work in terms of a leg press?
The leg press is the extension of the hip and leg against a force. Beginning at the hip, the gluteal muscles extend the femur with respect to the hip. Simultaneously, the quadraceps muscles extend the tibia and fibula with respect to the knee. On the way down, these muscles reduce the force that they produced during the extension. The loads are not transferred to other muscles. The forces just increase until the load is lifted, and then the forces are decreased in a controlled manner until the load is back to its initial position.
