abduction
 To abduct is to take or lead away
 (originally from the latin abducere, we use the word in modern speech as a synonym for "kidnap").
abduction movements therefore take one part of the body away from another and, in the case of the limbs, abduction of the hip joint takes the whole limb away from the mid-line of the body. Abducting both hips would spread the legs apart. hip abduction is accomplished by the smaller gluteal muscles (gluteus medius and minimus) - and possibly by tensor fasciae latae - all of which are supplied by the superior gluteal nerve (L4,5,S1).

However, the major importance of abduction does not lie in movements of the limb itself, but in movements of the trunk. If the limb is kept still, abduction of the hip joint will tilt the trunk and shift the centre of mass from the midline of the body to a position over the limb. This is essential in walking where only one foot is in contact with the ground during much of the stride.

No abduction goes on at the knee or ankle, but some abduction occurs in foot movements (see Tutorial on Movements of the Hind Foot) and the toes can be abducted or spread out.