Yudu - REPs - online access

Adduction Extension

External rotation

Internal rotation

Figure 4: Flexion and extension of the hip. This is an animation online.

1. Ischio-femoral ligament. 2. Ilio-femoral ligament. 3. Pubofemoral ligament. These ligaments tighten with the

effect of gravity, allowing us to stand without a great use of muscle power. Although there is a large mass of muscle around the hip, the prime purpose of this muscle is for locomotion, not stability. Similarly the stability of the SI joints and the pubic symphysis relies on ligament strength and opposition of the joint facets.

Movements of the hip joint Movement of the hip occurs in six ‘basic’ directions (figs 4-6): l 1-2 Flexion/extension (sagittal plane). l 3-4 Abduction/adduction (coronal plane). l 5-6 Internal/external rotation (around axis of the femur). Due to the structure of the hip, it can

also move in all those directions in one motion – a movement which has been termed circumduction.

Pectineus

Adductor brevis

Other hip adductor muscles not shown: adductor

longus which sits on top of adductor brevis and magnus

Adductor magnus

Figure 10: Hip abductor muscles

Other hip abductor muscles not shown: gluteus minimus

(fig.11) which lies under gluteus medius

Gluteus medius

Figure 5: Abduction and adduction of the hip. This is an animation online.

Muscle movements Muscle groups involved in movement of the hip can be divided in primary movers and secondary movers. The primary movers involve movement of the femur in relationship to the acetabulum, the secondary movers allow movement of the pelvis in relation to the ground.

Iliacus Sartorius

Psoas major

Psoas minor

Figure 6: Internal and external rotation of the hip. This is an animation online.

Primary movers The primary movers include five major groups which are primarily involved in generating motion. These are: 1. Hip flexors - ilio-psoas and rectus femoris (fig.7). 2. Hip extensors - gluteus maximus as well as medius/minimus to a lesser extent and the hamstrings - biceps femoris, semi-

Other extensor muscles not shown: gluteus medius (fig.10) and minimus (fig.11) which lie under gluteus maximus

Rectus femoris

Iliopsoas tendon (cojoined tendon of iliacus and psoas muscles)

Figure 7: Hip flexor muscles

Semi- membranosus

Pectineus Internal

obturator

Superior gemellus

Inferior gemellus

Obturator externus

Quadratus femoris

Gluteus maximus

Semi- tendinosus

Biceps femoris