SPECIAL LIGAMENTS. 



137 



Tnuscle. The internal lateral ligament is crucial, longer but 

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

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

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

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

 cavity on its outside, to a tuberosity outside the h6ad of the 

 radius. The joint possesses flexion and extension only. 



RADIO-ULNAR 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 radia- 

 ting ligaments are attached on both sides to 

 the superior part of the ulna and radius. They 

 are curved, and blend with the lateral liga- 

 ments 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 CABPUS. 



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-carjjal ; 

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

 the lower row and the metacarpus the carpo-metacarpal. 



Fig. 62. 



Liijaments of the car- 

 pus—anterior aspect, a, 

 Internal lateral ligament. 

 6, External lateral liga- 

 ment; c c, Anterior car- 

 pal ligaments ; d d. 

 Anterior carpo-metacar- 

 pal ligaments. 



Special Ligaments. 



Superior Carpal Ligaments. — The four bones of the upper row 

 ^re 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 



