LOWER LIMB HIP JOINT

Muscles of the Hip

Overview Muscles that cross the hip joint anteriorly Psoas major Illiacus Muscles of the gluteal area Gluteus maximus Gluteus medius Gluteus minimus Lateral rotators of the hip

Psoas Major & Iliacus Origin of Psoas Major: Lumbar vertebrae, intervertebral discs and transverse processes Origin of Iliacus: Fan shaped origin in fossa iliaca

Common insertion of Psoas Major and Iliacus: Psoas Major & Iliacus Common insertion of Psoas Major and Iliacus: Lesser trochanter of femur

Psoas Major & Iliacus Action: Flexion of hip joint Lateral rotation of hip joint Stabilisation of hip joint during walking

Psoas Major & Iliacus Innervation: Psoas Major L2-L3 Iliacus Femoral nerve

Gluteus Maximus

Gluteus Maximus Origin: Lateral surface of ileum, behind the gluteal line Dorsal surface (posterior surface) of sacrum, coccyx and sacrotuberous ligament Ileum Ischium Pubis

Gluteus Maximus Insertion: Superficial ¾ ~ iliotibial tract Deep ¼ ~gluteal tuberosity on femur

Gluteus Maximus Action: Powerful extensor of the hip joint ~ only when strength is needed i.e.: Rising from a sitting position Climbing stairs Running Powerful lateral rotator of the thigh ~ when thigh is extended Regulate flexion when sitting Losses strength when thigh is flexed

Gluteus Maximus Innervation: Inferior gluteal nerve

Gluteus Medius Origin: Lateral aspect of ileum ~ between anterior and posterior gluteal lines

Gluteus Medius Insertion: Oblique insertion onto greater trochanter of femur

Gluteus Medius Action: NB: Muscle lies in same coronal plane as hip joint In the anatomical position, the greater trochanter of the femur lies slightly more posterior than the hip joint

Gluteus Medius Action: Abduction, as well as, medial rotation of hip joint Plays an important role in walking When the support of one leg is taken away in upright standing position, the opposite muscle will contract reflexively. This prevents the pelvis from tilting

Gluteus Medius Action: Paralysis of muscle causes the typical “goose gait” (Trendelenburg sign)

Gluteus Medius Innervation: Superior gluteal nerve

Gluteus Minimus Origin: Lateral surface of the ileum ~ between anterior and inferior gluteal lines

Gluteus Minimus Insertion: Anterior surface of the greater trochanter of the femur

Gluteus Minimus Action: Relationship of gluteus minimus the same as gluteus medius, therefore the action is essentially the same

Gluteus Minimus Innervation: Superior gluteal nerve

Lateral rotators of the hip Piriformis Internal obturator Superior gemellus Inferior gemellus Quadratus femoris External obturator

Lateral rotators of the hip