Hip Joint

Question 1

Classification of the Hip Joint.

Answer 1

Synovial, polyaxial, ball and socket joint capable of 3 degrees of freedom

Question 2

Name 3 ligaments that limit and control movement of the hip joint.

Answer 2

• Iliofemoral ligament.
• Pubofemoral ligament.
• Ischiofemoral ligament.

Question 3

Name the movements which occur at the hip joint. (full planar range)

Answer 3

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

(Plus circumduction as a combined movement)

Question 4

For 2 of the individual movements at the hip joint, name 1 of the main muscles responsible for producing that movement.

Answer 4

• Flexion = Psoas Major and Iliacus (iliopsoas)
• Extension = Gluteus Maximus and Hamstring group.
• Abduction = Gluteus Medius and Gluteus Minimus
• Adduction = Adductor Brevis ,Adductor Longus, and Adductor Magnus.
• Lateral Roatation = Gluteus maximus, piriformis, Obturator Externus and Internus, Gemelli and Quadratus Femoris.
• Medial Rotation = Anterior aspect of Gluteus Medius and Gluteus Minimus, Tensor Fasciae Latae.

Question 5

Give the attachments of the capsule of the hip joint.

Answer 5

• Anteriorly to intertrocanteric line.
• Above the base of the neck of the femur.
• Posteriorly to the neck above the trochanteric crest.
• -Surrounds the acetabulum, labrum and transverse ligament

Question 6

Briefly describe the acetabulum

Answer 6

A cup shaped articular fossa that faces laterally, anteriorly and inferiorly.

• Is a hemispherical hollow formed by the fusion of the ilium, ischium and pubis. Contains a horseshoe shaped lunate articular surface covered in hyaline cartilage, thickest superiorly.
• Central section is non-articular where ligamentum teres arises.
• Rim is not complete inferiorly (acetabular notch) spanned by the transverse ligament.
• Fossa deepened by fibrocartilaginous labrum which attaches to the rim of the acetabulum

Question 7

Describe the head of the femur

Answer 7

-Ball shaped Head (except fovea) is covered by hyaline cartilage, thickest superiorly.
The fovea capitis is the small central pit which is posteromedial for attachement of ligamentum teres.
-Head is carried on angled neck.
-Spherical shape.

Question 8

Give factors that limit the range of movement at the hip joint

Answer 8

Flexion- soft tissue apposition of thigh to abdominals, tension in Gluteus maximus or hamstrings
Extension- tension in the Rectus femoris or iliopsoas, Iliofemoral ligament
Abduction- tension in adductor group, Greater trochanter meeting pelvis medial band iliofemoral & Pubofemoral ligt
Adduction- other leg(soft tissue) tension in antagonists Lateral band of iliofemoral ligt, ligamentum teres
Lateral Rotation- tension on medial rotators and lat band of iliofemoral ligament
Medial Rotation- tension in lateral rotators and ischiofemoral femoral ligament, post capsule

Question 9

Hip joint stability factors

Answer 9

○ Strong surrounding ligaments
○ Cup shaped acetabulum
○ Deepened by the acetabular labrum
○ Strong capsule
○ Vacuum effect of ball within socket
○ Oblique angle of femoral neck - weight bearing causes femoral head to drive deeper into the acetabulum
○ Arrangement of powerful surrounding muscles

Question 10

Give Hip joint movements and ROM ranges

Answer 10

Flexion: 100-120
Extension: 15-20
Abduction: 40-45
Adduction: 15-30
MR: 30-40
LR: 45-60