282 A MANUAL OF ANATOMY 



Angular Movement. — This increases or diminishes the angle 

 between two or more bones. When it takes place in a forward and 

 backward direction, so as to bend or straighten a joint, it is spoken of 

 as flexion and extension. When it takes place laterally, away from 

 or towards the median plane of the body, it is called abduction and 

 adduction. In the case of the hand the median line from or towards 

 which abduction and adduction take place is a line passing through 

 the centre of the middle finger, and in the case of the foot, through 

 the centre of the second toe. 



Circumduction. — This consists of the four forms of angular 

 movement, occurring successively in such sequence as flexion, 

 abduction, extension, and adduction. It occurs at ball-and-socket 

 and condylar joints, and during the movement a part of the limb 

 describes a cone, the apex of which is formed by the proximal end 

 at the moving joint, whilst the base is described by the distal end. 



Rotation.- — This is movement of a bone round its axis without 

 much disturbance of its position. It occurs at enarthrodial and 

 trochoidal joints, and also at the knee-joint, which is a ginglymus. 



Gliding Movement. — This consists of a simple to-and-fro or sliding 

 movement of two articular surfaces, as between the articular surfaces 

 of vertebrae, and at the carpal and tarsal joints. When the gliding 

 is combined with a certain amount of turning or rolling, so as toj 

 bring different parts of the articular surfaces successively intoJ 

 contact in different positions of the joint, the movement is known | 

 as coaptation, as at the femoro-patellar joint. 



A description of the different articulations will be found in con-| 

 nection with the regions to which they belong. 



