Lesson
Hip Joint Muscles - continued
NOTES:
1.Gluteus Maximus used mainly as a thigh extensor in stepping up, climbing, running, not in walking. Glue Max. + Hamstrings provide the main control in body forward bending, mainly a hip joint movement
2.Although hamstrings do flex knee and extend hip to move thigh back, their main role along with Glte Max. is raising a flexed trunk, a power requiring job, especially given the short lever (moment) arm – the ischium and its ramus
3.Gluteus medius important in walking, running and when bearing weight on one leg
4.Simultaneous action of hamstrings on hip and knee: if runner is accelerating towards a bend, hamstrings lift the trunk to more upright position, bend knee of swinging leg and rotate the stance knee to produce a turning force. The body is changing posture and accelerating, so there are additional forces affecting the hamstrings
5.The quadriceps group of muscles is powerful. The group must work strongly throughout its full range of motion. It looses strength and bulk rapidly if any of its muscles or the knee are injured. It takes months to regain its power but only days to lose it
6.Two-jointed rectus femoris is active during hip flexion AND knee extension. SO, it is more effective as hip flexor when knee flexed
7.Gluteus medius is the prime hip abductor (Gluteus Minimus assists). If body weight is supported by right leg during walking, right hip abductors contract isometrically and eccentrically to prevent left side of pelvis being pulled down by the weight of swinging left leg