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.
The greater your degree of hip extension, the more work is performed by your glutes and hamstrings--sprinting will build these muscles more than jogging. When you swing your leg forward to take another step you use your hip flexors at the front of your hip and your rectus femoris, one of the quadriceps muscles.