Movement of the human body is a topic discussed in anatomy and physiology classes as well as many other health science courses. Movement of the body occurs at joints and allows you to move appendages such as your arms and legs. Various types of movements can be performed by specific joints. Certain joints of the body may only be able to perform one or two movements, while others may be able to perform several.
Flexion and Extension
Flexion and extension are opposing movements. Flexion occurs when the body or joint bends to decrease the angle between two body parts. Extension is the exact opposite of flexion. Extension increases the distance between two body parts. An example that includes both flexion and extension is performing a situp. When you come up during a situp, you decrease the distance between your legs and your upper body. This represents flexion. When you release the situp and return to your beginning position, you are lengthening the body and performing extension. Flexion of the foot has specific names. Dorsiflexion and plantarflexion are used to describe foot and ankle flexion. Dorsiflexion occurs when the foot is bent to bring the toes upward toward the nose. Plantarflexion is the exact opposite, occurring when the foot is flexed to point the toes toward the ground.
Rotation
Rotation can be simply described as any movement that involves turning. Rotation is medial or lateral according to the direction in which the turning occurs. Medial rotation occurs when a body part is turned toward the midline, or trunk of the body. Lateral rotation is the opposite and occurs when a body part is turned toward the side of the body. When referring to rotation of the spine, it is common to describe spinal rotation simply as rotation the right and rotation to the left. Supination and pronation are used to describe rotation, such as of the forearm and hand. During supination, the hand is moved laterally to a position in which the palm faces upward. Pronation occurs when the forearm is rotated medially, to a palm down position.
Abduction and Adduction
Abduction and adduction are also opposing movements. Abduction occurs when any part of the body is moved out to the side, away from the trunk. Abduction of the hip is a classic example of this type of movement. During hip abduction, the leg is moved so that the thigh is moved out to the side of the body. Moving the thigh from this outward position back in toward the midline of the body is referred to as adduction. Adduction occurs when body parts are moved closer to or across the midline of the body. Abduction and adduction are mainly used when describing movements of the shoulder and arm and hip and leg.
Circumduction
Circumduction is a combination of abduction, adduction, flexion and extension. Circumduction can only be performed by joints that allow all four movements. The shoulder, hip and fingers are common sites of circumduction. All four movements are performed at the same time so that the distal end of the body part traces a circle. An example of this is holding the arm out in front or to the side of the body and tracing a circle with your fingertips. This is considered shoulder or arm circumduction.
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