Ergonomics - Glossary of Terms

Abduction (ab-duk’ shun) – movement away from the midline of the body, as in moving the arms straight out to the sides.

Adduction (ad-duk’ shun) – movement toward the midline of the body, as in bringing the arms back to their original position beside the body.

Extension – a straightening motion that increases the angle between bones, as in straightening the fingers to open the hand, or moving the forearm and hand away from the shoulder.

Flexion (flek’ shun) – a bending motion that decreases the angle between bones, as in bending the fingers close to the hand, or raising the forearm and hand toward the shoulder.

Pronation (pro-na’ shun) – turning of the palm down or backward. A neutral postures consists of near 45° pronation recommended by ergonomic experts.

Radial/Ulnar Deviation – the bending of the hand at the wrist, toward or away from the thumb (side to side movement)

Rotation – a twisting or turning of a bone on its own axis, as in turning the wrist from palm up to palm down

Supination (su-pin-a’ shun) – the act of turning the palm up or forward