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|Anatomical terms of motion|
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Muscles drive all the movements in the human body, both voluntary and involuntary. They move organs, members, and the whole body in specific ways described by anatomical terminology. The terminology describes movement according to its direction. Anatomists use a unified set of terms to describe most of the movements, although other, more specialized terms are necessary for describing movements such as those of the hands, feet, and eyes.
The anatomical positions of the joints are the basis for description of most obvious skeletal movements, but there also are classes of movement, both voluntary and involuntary, in which joints and even skeletal elements play little part, such as movements of eyes, viscera and lips.
Motions are classified after the anatomical planes they occur in, although movement is more often than not a combination of different motions occurring simultaneously in several planes. Additionally, motion may be divided into gross motion, affecting the large joints (such as legs, arms, and torso), and fine movements, which describe those made by the fingers, toes, feet or wrist. The study of movement is known as Kinesiology, and a categoric list of movements of the human body and the muscles involved can be found at List of movements of the human body.
Motions can be split into three categories as per how they engage different joints of the body:
Apart from this motions can also be divided into:
The prefix hyper- is sometimes added to describe movement beyond the normal limits to a limb's or organ's motion, such as in hyperflexion or hyperextension. Such movements are variously important; they may be used in surgery, such as in temporarily dislocating joints for surgical procedures, and also may be important in that they may seriously stress the joints involved. Such prefixes are common in Medical terminology. If a part of the body such as a joint is overstretched or "bent backwards" because of exaggerated extension motion, then one speaks of a hyperextension (as with the knee). This puts increased stress on the ligaments of the joint, and need not always be a voluntary movement, but may occur as part of accidents, falls, or other causes of trauma. Hyperextension is also sometimes defined as normal movement into the space posterior to the anatomical position.
These are general terms that can be use to describe most movements the body makes. Most terms have a clear opposite, and so are treated in pairs.
Flexion describes a bending movement that decreases the angle between two parts. For example, bending the elbow, or clenching a hand into a fist, are examples of flexion. When sitting down, the knees are flexed. Flexion of the shoulder or hip refers to movement of the arm of leg forward. 
Extension is the opposite of flexion, describing a straightening movement that increases the angle between body parts. When standing up, the knees are extended. Extension of the hip or shoulder moves the limb backward.  In a conventional hi-five, the fingers are fully extended.
Abduction refers to a motion that pulls a structure or part away from the midline of the body (or, in the case of fingers and toes, spreading the digits apart, away from the centerline of the hand or foot). Abduction of the wrist is also called radial deviation.  Raising the arms laterally, such as when tightrope-walking, is an example of abduction at the shoulder. 
Adduction refers to a motion that pulls a structure or part toward the midline of the body, or towards the midline of a limb. Dropping the arms to the sides, or bringing the knees together, are examples of adduction. In the case of the fingers or toes, adduction is closing the digits together. Adduction of the wrist is also called ulnar deviation. Bringing the arms closer to the body is an example of adduction at the shoulder. 
The terms elevation and depression refer to movement above and below the horizontal. They derive from the Latin terms of the same meaning [c]
Rotation of body parts is referred to as internal or external, referring to rotation towards or away from the center of the body.
Internal rotation (or medial rotation) refers to rotation towards the axis of the body.  For example, a roman salute, in which the arm is placed against the chest, is an example of internal rotation.
The swinging action made during a tennis serve is an example of circumduction
Dorsiflexion and plantarflexion refers to extension (dorsiflexion) or flexion (plantarflexion) of the foot at the ankle.
Dorsiflexion is the movement which decreases the angle between the dorsum (superior surface) of the foot and the leg, so that the toes are brought closer to the shin.:123 and applies to the upward movement of the foot at the ankle joint.
Plantarflexion is the movement which increases the approximate 90 degree angle between the front part of the foot and the shin, as when depressing an automobile pedal or standing on the tiptoes. The word "plantar" is commonly understood in medical terminology as the bottom of the foot – it translates as "toward the sole". This movement is normally performed in either the supine, prone or standing position.
Tibialis anterior muscle labeled at top center, and extensor muscles labeled at right
Palmarflexion and dorsiflexion refer to movement of the flexion (palmarflexion) or extension (dorsiflexion) of the hand at the wrist. For example, prayer is often conducted with the hands dorsiflexed.
A ballerina, demonstrating dorsiflexion of the feet.
Pronation at the forearm is a rotational movement at the radioulnar joint, or of the foot at the subtalar and talocalcaneonavicular joints. For the forearm, when standing in the anatomical position, pronation will move the palm of the hand from an anterior-facing position to a posterior-facing position without an associated movement at the shoulder (glenohumeral joint).
Supination of the forearm occurs when the forearm or palm face to the front (anteriorly) of the body. Supination of the foot occurs when the foot rolls outwards, placing most of the weight onto the outside of the foot and raising the arch. It is a compound movement that combines adduction, inversion, and plantar flexion.
Inversion and eversion refer to movements that tilt the sole of the foot away from (eversion) or towards (inversion) the midline of the body.
Unique terminology is also used to describe the eye. For example:
Such terms include:
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