114 LABORATORY MANUAL OF HUMAN ANATOMY 



are concerned in flexion, extension, abduction, and adduction of 

 the hand? Of what especial advantage are the multiple bones 

 and joints of the carpus? 



Radio-ulnar Joints. (See Figs. 44, 45, and 46.) 

 These joints consist of 



(a) Proximal radio-ulnar articulation (articulatio radio-ulnaris proxi- 

 malis) (0. T. superior radio-ulnar). 



FIG. 46. 



Tend. M. bicipitis 



-Chorda obliqua (Lig. of Weitbrecht) 



.Ligamentum interosseum 



-Orifice for the A. interossea volaris 



The interosseous membrane of the forearm, volar surface. (After Poirier et Charpy, 

 Traite d'Anat. hum., Paris, 1899, t. i. p. 655, Fig. 664.) 



(&) Distal radio-ulnar articulation (articulatio radio-ulnaris distalis) (0. 



T. inferior radio-ulnar). 

 (c) Interosseous membrane and oblique cord (membrana interossea anti- 



brachii et chorda obliqua). 



To expose the ligaments, the muscles must be completely re- 

 moved from the dorsal and volar surfaces of the forearm. 



(a) Proximal radio-ulnar joint. 



What bony surfaces are concerned? Study carefully the annular 



