SPECIAL CARPAL LIGAMENTS. 



137 



muscle. The internal lateral ligament is crucial, longer but 

 less strong than the external; it stretches from a small tuberos- 

 ity on the inner side of the internal condyle of the humerus to 

 the head of the radius. The external lateral ligament, crucial, 

 short and thick, passes from a ridge on the epitrochlea, and a 

 cavity on its outside, to a tuberosity outside the head of the 

 radius. The joint possesses flexion and extension only. 



KADIO-ULXAE, JOINT. 



This articulation, small and very firm, is 

 formed by the articular surfaces of the radius 

 and ulna, and consists of two true and two 

 mixed joints. The arciform or superior 

 radiating ligaments are attached on both sides 

 to the superior part of the ulna and radius. 

 They are curved, and blend with the lateral 

 ligaments of the elbow. Below the radio-ulnar 

 arch are a few fibres, which constitute the 

 inferior radiating ligament. The surfaces 

 above and beneath the radio-ulnar arch are 

 joined by the interosseous ligaments, which 

 ossify early in life. The motion is practically 

 nil. 



THE CARPUS. 



The ligaments of this joint, or rather group 

 of joints, are special and common. The 

 articulations between the bones of the upper 

 row may be termed the superior carpal ; 

 those between the bones of the lower row the 

 inferior carpal ; between the radius and the 

 upper row we have the radio-carpal ; between 

 the upper and lower rows the inter-carpal ; and between the 

 lower row and the metacarpus the carpo-nietacarpal. 



I'lG. 52. 



Ligaments of the car- 

 pus— anterior aspect, a, 

 Internal lateral ligament. 

 h. External lateral liga- 

 ment ; c c, Anterior car- 

 pal ligaments ; a d. 

 Anterior carpo-metacar- 

 pal ligaments. 



Spec ial Ligaments. 

 Superior Carpal Ligaments. — The four bones of the upper 

 roiu are held together by three anterior and three interosseous 

 ligaments. The anterior are flat bands placed one between each 

 pair of bones ; and the two inner ones are covered by and 

 attached to the capsular ligament ; the third, the median 



