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.
Additional muscles, such as the rectus femoris and the sartorius, can cause some movement in the hip joint. However these muscles primarily move the knee, and not generally classified as muscles of the hip. The hamstring muscles, which originates mostly from the ischial tuberosity inserting on the tibia/fibula, has a large moment assisting with hip extension.