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.
Flexing your hips to lower your body while lunging also recruits the rectus femoris. The rectus femoris is a particuarly powerful knee extender when your hips are extended, and it is the only quadriceps muscle that crosses your hip joint.