Knickerbocker's theory emphasizes on the interdependence of major players in the same industry. Imitation is the name of the game where firms try to match each other's moves to keep each other in check so as not to allow a rival gain a competitive advantage over others.
hamstrings. extend the hip and flex the knee against resistance and are important knee stabilizers. help control hip flexion in weightbearing position by contracting eccentrically when the flexion occurs in same direction as gravity as dead lift or hip=hinge position.
Rectus femoris. A muscle in the quadriceps, the rectus femoris muscle is attached to the hip and helps to extend or raise the knee. This muscle is also used to flex the thigh. The rectus femoris is the only muscle that can flex the hip.