72 



TOPOGEAPHICAL ANATOMY OF 



dissector should satisfy himself as to the range and nature of the 

 possible movements. Obviously the arrangement itself of the bones 

 points to the hinge-like character of the combined articulations. The 

 most free movement is clearly one of flexion and extension ; but this, 

 it must be remembered, is the result of the sum of the movements 

 between the radius and the carpus, and between the two rows of 

 carpal bones — the former contributing more than the latter. Between 

 the distal row of bones and the bases of the metacarpals there is no 



Radius 



Accessory carpal bone 

 (pisiform). i 



Lis. collaterale laterale. 



Intermediate carpal bone 

 (lunar). 



Ulnar carpal bone (cunei- 

 form). 



Fourth carpal bone 

 (unciform). 



Third metacarpal bone. 



Fourth metacarpal 

 bone. 



Fig. 50. — Lateral Aspect of the Carpal Articulations. 



1. = Ligament from accessory carpal bone to radius. 



2. = Dorsal ligament from accessory carpal to ulnar carpal bone. 



3. = Ligament from accessory carpal to fourth carpal and fourth metacarpal bones. 



4. = Dorsal ligament connecting ulnar and intermediate carpal bones. 



5. = Dorsal ligaments connecting third and fourth carpal bones. 



b'. = Dorsal ligaments connecting third and fourth carpal bones to third and fourth 

 metacarpals. 



movement of a nature that would add to flexion and extension, liga- 

 ments being so disposed as to prevent more than a limited amount of 

 gliding of one bone over another. 



The movement of flexion is accompanied by the gliding of one 

 carpal bone over its neighbour ; especially is this the case between the 

 different members of the proximal row. 



Under normal conditions it is doubtful if there is any movement of 

 abduction and adduction in the carpal articulations themselves ; though, 

 owing to the form of the bony surfaces, the distal part of the limb is 

 slightly abducted during flexion. 



