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.
hip flexor, 3 muscles; psoas major, psoas minor, and the iliacus. flexes the hip when lumbar spine is stabilized; such as in a straight leg raise, performed while laying face up,, it moves the trunk toward the thigh if femur is stabilized as in situp done with legs held down; movement must occur against gravity.