SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 349 



Trace to their origins the radial group of muscles : 



i . Supinator longus, to upper two-thirds of external condylar ridge of the 

 humerus. (Fig. 246.) 



Biceps 



Brachialis anticus 

 Brachio-radialis 



.Extensor carpi radialis lougior 



Extensor communis digitorum 



Extensor carpi radialis brevior 



Extensor ossis metaearpi pollicis 



Extensor brevis polhcid 



Extensor longus pollicis 



Triceps 



Flexor carpi ulnaris 



Extensor carpi ulnaria 



Extensor minimi digiti 



ULNA 



FIG. 243. MUSCLES OF THE RADIAL SIDE AND THE BACK OF THE FOREARM. 



2. Extensor carpi radialis longior, trace to the lower one-third of external 

 condylar ridge of the humerus. 



3. Extensor carpi radialis brevior, to the outer condyle of the humerus. 



To do this properly, begin with the tendon and follow it upward, dividing the 



