Flexion and Extension at the Coxal Joint Hip Action

Coxal Joint Human’s are bipedal. The very nature of our anatomical position puts a lot of pressure on the area of our hips. The legs are responsible for moving humans throughout our environment and in this role must be organized in a way that allows fluid articulation while supporting a great deal of weight and pressure. The organization of this ball and socket joint allows for these functions and many more. Through this discussion of formations on the femur and coxa, the binding that occurs through the ligaments of this area, and the identification of powerful muscles to specific locations around these structures, you will have a better understanding of how the form of the coxal joint supports its functions.

Bone Structures are the first thing to contribute to allowing movement. Movement at the Coxal joint begins between the bone formations created by the femur as it inserts into the coxa. The femur’s epiphysis creates a head that forms a circular “ball” for the ball and socket joint. This head fits into the acetabulum of the coxa. COXA FEMUR

Bone Formations As you can see in the visual to the right, the head of the femur creates a ball-like structure that fits into the cup-like structure on the coxa (hip). As this ball swivels in the cup it is able to move the leg in a circle-like pattern called circumduction.

Moving the femur to the front of the body (anterior) within the cup of the coxa is called flexion. Opposing this action is extension. This is when the femur rotates to the back of the body or posterior.

When the femur pulls away from the mid-line of the body out to the sides it is called abduction. The opposite of this action is adduction when the femur is added back to the midline of the body.

Bones cannot move the body alone. Ligaments help to bind the bones together and hold the articular surfaces together to ensure the movements are created as intended to avoid damage to tissues.