Chapter 7: The Lower Extremity: The Hip Region

Outline

• The Pelvic Girdle

  Structure

  Movements of the Pelvis

• Relationship of the Pelvis to the Trunk and Lower Extremities

  Primary Movements of the Pelvis

  Secondary Movements of the Pelvis

  Muscles of the Pelvis

• The Hip Joint

  Structure

  Ligamentous Reinforcements

  Movements of the Femur at the Hip Joint

• Muscles of the Hip Joint

  Location

  Characteristics and Functions of Hip Joint Muscles

  Muscular Analysis of the Fundamental Movements of the Thigh

• Common Injuries of the Thigh, Hip Joint, and Pelvis

  Contusions

  Myositis Ossificans

  Strains of the Hamstring Muscle Group

  Hip Fracture

• Laboratory Experiences

Objectives

At the conclusion of this chapter, the student should be able to:

1. Name, locate, and describe the structure and ligamentous reinforcements of the articulations of the pelvic girdle and hip joint.

2. Name and demonstrate the movements possible in the pelvic girdle and hip joint, regardless of starting position.

3. Name and locate the muscles and muscle groups of the pelvis and hip, and name their primary actions as agonists, stabilizers, neutralizers, or antagonists.

4. Analyze the fundamental movements of the pelvis and thigh with respect to joint and muscle actions.

5. Describe the common athletic injuries of the pelvis, hip, and thigh.

6. Perform an anatomical analysis of the hip region in a motor skill.

The relationship between the pelvic girdle and hip is somewhat similar to that between the shoulder girdle and shoulder joint. Just as the scapula tilts or rotates to put the glenoid fossa in a favorable position for the movements of the humerus, so does the pelvic girdle tilt and rotate to put the acetabulum in a favorable position for the movements of the femur. There are these differences, however. Whereas the left and right sides of the shoulder girdle can move independently, the pelvic girdle can move only as a unit. The difference in depth of socket also limits the movement at the hip joint but is vital to accommodate the weight-bearing function of this joint. Furthermore, whereas the movements of the shoulder girdle take place in its own joints (sternoclavicular and acromioclavicular), the pelvic girdle is dependent on the lumbosacral and other lumbar joints, and the hip joints, for its movements. Hence, an analysis of the movements of the pelvic girdle must always be stated in terms of both spinal and hip action.

The Pelvic Girdle

Structure

The pelvis (Figure 7.1) is a rigid, bony basin that serves as a massive connecting link between the trunk and the lower extremities. Each pelvic bone (os innominatum) is made up of three bones: the ilium, ischium, and pubis. These bones become fused into a single bone by about the time of puberty. The two pelvic bones together form the pelvic girdle. This bony girdle or basin is firmly attached to the sacrum at the sacroiliac articulation, an articulation that is difficult ...