Bony Landmarks — the Ankles
The bony landmarks that represent the ankles are actually the ends of the two lower leg bones, the tibia and the fibula. The bony protrusions are called the medial and lateral malleolus. The medial malleolus is the end of the tibia, which sits on the inside of the foot. The lateral malleolus is the end of the fibula, which sits on the outside of the foot.
The ankle actually consists of all the tarsal bones. (These seven bones were discussed earlier.) The talus is considered the real anklebone and is the initial weight-bearing bone during the action of walking.
Another area of importance in dealing with the ankle is the joint involved with the movement of this area. A joint is a point of contact between bones. There are different classifications for joints depending upon structure or function.
Structural classification depends upon the presence or absence of space between the bones that are touching. The joints you are dealing with have a cavity, known as a
Functional classification deals with the degree of movement the joint allows. A diarthrosis is a freely movable joint, which is the type of joint you are involved with at this time. These joints have a variety of shapes and allow a range of movement. They are covered with a protective cartilage that allows for freer movement and provides shock absorption.
Flexion happens when we bend at a joint, like bending a knee or an elbow. Extension often happens when we return the arm or leg to its original position after flexing. Some hinge joints can hyperextend; that's how our heads can bend backward.
The ankle joint is also known as the
The synovial joints have a subgroup known as
Inversion moves the soles inward, so they face each other.
Eversion moves the soles away, so they face away from each other.
Dorsiflexion bends the foot up.
Plantar flexion bends the foot down.
Abduction moves the foot away from the center of the body.
Adduction also moves the foot toward the center of the body.
Although not special movements, there are two others that are key to some of these movements: supination is a three-point movement of inversion, plantar flexion, and adduction; and pronation is a three-point movement of eversion, dorsiflexion, and abduction.