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.
1 What Muscle Is Used to Do Sit-ups?  You flex your hips by bending your trunk forward and you extend your knees when you straighten your legs. Walking, running and lifting objects from the floor all require your to flex your hips and extend your knees. The iliopsoas, tensor fascia latae, pectineus and quadriceps all flex the hip, but the quadriceps is the only one to extend the knee. The iliacus and the psoas major are located in the pelvis and they merge to form the iliopsoas muscle, which is the main hip flexor.