140 



ARTHROLOGY. 



and inferior trapezial ligaments. Its anterior surface is attached 

 to the two rows of bones, while its posterior is smooth, for the 

 passage of the great flexor tendons ; the inferior carpal or check 

 ligament is continuous with it. A ligamen- 

 tous structure passes obliquely downwards from 

 the posterior border of the trapezium to the 

 large and inner metacarpal bones, completing 

 the carpal groove or sheath for the flexor 

 tendons ; this is the posterior or investing 

 annular ligament. The carpal or check 

 ligaments, superior and inferior, will be alluded 

 to in describing the muscles of this region. 



The synovial capsules are four, perhaps 

 five two small and three large. Of the 

 latter, one is for the radius and the upper row, 

 extending between the bones as far as the 

 interossei ; another is situated between the 

 upper and lower rows, and a third between 

 the lower row and metacarpus, dipping be- 

 tween its large and small bones. There is 

 usually a separate synovial capsule between 

 the trapezium and cuneiform bone, and perhaps 

 one for the pisiform, when present. 



Motion in the carpus takes place chiefly in 

 the radio-carpal portion, to a far less degree 

 in the intercarpal, and very slightly in the 

 carpo-metacarpal ; the movements are flexion and extension ; very 

 slight lateral and circumductive movements are possible. 



Superficial ligaments 

 of the carpus posterior 

 view, a, Posterior annu- 

 lar ligament ; b b, Pos- 

 terior common ligament. 



METACARPAL ARTICULATION. 



This consists of diarthrodial and synarthrodial joints. The 

 latter are furnished with interosseous ligaments which very 

 generally become ossified ; the articular surfaces of the former 

 are held together, partly by those carpal ligaments which sur- 

 round them, and partly by the interosseous ligaments just 

 named. 



METACARPO-PHALANGEAL ARTICULATION. 



This, which is popularly termed the fetlock joint, is formed 

 by the large metacarpal bone, the proximal phalanx, and a pair 



