Hip Joint:Anatomy,Movement & Muscle involvement

The hip joint is a ball and socket variety of synovial joint, formed by an articulation between the acetabulum of the pelvic bone and the head of the femur.

Ligaments of the Hip joints

The ligaments of the hip joint exploit to increase stability. They divided into two groups – intracapsular and extracapsular:

Intracapsular ligament

The single intracapsular ligament is the ligament of head of the femur. It is a comparatively small structure, which goes from the acetabular fossa to the fovea of the femur.

Extracapsular ligament

There are three principal extracapsular ligaments, connected with the outer surface of the hip joint capsule:

Iliofemoral ligament – connecting the anterior inferior iliac spine and the intertrochanteric line of the femur.

It produces a ‘Y’ shaped image and limits hyperextension of the hip joint.

Ischiofemoral – spans within the body of the ischium and the greater trochanter of the femur.

It becomes a spiral orientation and prevents extreme extension.

Pubofemoral – spans within the superior pubic rami and the intertrochanteric line of the femur.

It produces a triangular shape and prevents undue abduction and extension.

Neurovascular Supply of the Hip joint

The arterial supply of the hip joint is medial and lateral circumflex femoral arteries – branches of the profunda femoris artery. They anastomose at the bottom of the femoral neck to form a ring, from which tinier arteries arise to supply the hip joint itself.

The medial circumflex femoral artery is responsible for the majority of the arterial supply. Damage to the medial circumflex femoral artery can result in avascular necrosis of the femoral head.

The head of the femur supplied by the superior/inferior gluteal arteries provides some additional supply.

The hip joint is innervated by the obturator nerve, femoral nerve, superior gluteal nerve, and nerve to quadratus femoris.

Movements of the hip joints

  • Abduction
  • Adduction
  • Flexion
  • Extension
  • Medial Rotation
  • Lateral Rotation

 

Abduction

In abduction-lower limb away from the midline in the coronal plane.

Muscles involvement in abduction:  Gluteus medius, gluteus minimus and the deep gluteals (piriformis, gemelli etc.)

Adduction

In adduction-lower limb towards midline in the coronal plane.

Muscles involvement in abduction: adductors longus, brevis and magnus, pectineus and gracillis

Flexion

Flexion-lower limb forwards in the sagittal plane.
Muscles involvement in flexion: iliopsoas, rectus femoris, sartorius

Extension

In extension-lower limb backward in the sagittal plane.
Muscles involvement in extension: gluteus maximus, semimembranosus, semitendinosus and biceps femoris

Medial rotation

In medial Rotation-rotation towards the midline, so that the big toe is pointing medially.
Muscles involvement in medial rotation: gluteus medius and minimus, semitendinosus, and semimembranosus

Lateral rotation

In lateral Rotation -rotation away from the midline, so that the big toe is pointing laterally.
Muscles involvement in lateral rotation:– biceps femoris, gluteus maximus, and the deep gluteals (piriformis, Gemelli etc.)