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 four muscles that run on the front of each thigh, three to the knees and one over the hip joint, form the group of prime movers called quadriceps femoris -- the quads. Together, the rectus femoris, vastus medialis, vastus intermedius and vastus lateralis extend the knees.