FASCIA AND MUSCLES OF THE FOREARM AND MANUS 



305 



Strudure.—lt is almost entirely fleshy. The deep face is adherent to the joint 



CofpSLUG. 



iSeZafo-ons.— Superficially, the triceps muscle; deeply, the humerus and the 

 elbow jomt. 



Blood-supply. — Deep brachial artery. 

 Nerve-supply. — Radial nerve. 



Deep flexor tendon 



■■Distal end of small metacarpal bone 

 "Suspensory ligament 



Branch of superficial flexor tendon 

 Distal digital annular ligament 

 Upper border of cartilage 

 of third phalanx 



rV. FASCIA AND MUSCLES OF THE FOREARM AND MANUS 

 (FASCIA ET MUSCULI ANTIBRACHII ET MANUS) 



The forfearm is covered on three sides by the muscles of this group, leaving 

 the medial surface of the radius for the most part subcutaneous. The extensors of 

 the carpus and digit lie on the 

 dorsal and lateral parts of the 

 region, while the flexors oc- 

 cupy the volar surface. 



The fascia of the fore- 

 arm (Fascia antibrachii) 

 forms a very strong and com- 

 plete investment for all the 

 muscles of the region. The 

 superficial fascia is thin, and 

 blends at the carpus with the 

 deep fascia ; it furnishes inser- 

 tion to the posterior super- 

 ficial pectoral muscle. The 

 deep fascia is very strong and 

 tendinous in character. It 

 furnishes insertion at its 

 proximal and medial part to 

 the tensor fasciae antibrachii 

 muscle; at its proximal anter- 

 ior and lateral part to the 

 brachiocephalicus and biceps. 

 It is attached at the elbow to 

 the lateral tuberosities of the 

 humerus and radius, to the 

 ulna, and to the collateral 

 ligaments. On [the medial 

 surface of the forearm it 

 blends with the periosteum 

 on the subcutaneous surface 



of the radius. It is closely adherent to the surface of the extensor muscles, but is 

 rather loosely attached to the flexors; near the carpus it blends with the tendons 

 attached to the accessory carpal bone. From its deep face are detached intermus- 

 cular septa, which form sheaths for the muscles and are attached to the underlying 

 bones. The principal septa are: (o) One which passes between the common digital 

 extensor and the lateral extensor and ulnaris lateralis ; (b) one betAveen the com- 

 mon extensor and the extensor carpi radialis; (c) one between the medial and middle 

 flexors of the carpus. 



The carpal fascia (Fascia carpi) is a direct continuation of that of the forearm. 

 It is attached chiefly to the tuberosities at the distal end of the radius, to the ac- 

 cessory carpal bone, and to the carpal collateral ligaments. In front it forms the 

 so-called dorsal annular ligament of the carpus (Lig. carpi dorsale), bridging ov^ 



Fig. 278. — Digit of Hobse; Volar View. 

 14, Deep flexor tendon; 15, superficial flexor tendon; 16, volar an- 

 nular ligament of fetlock; 17, proximal digital annular or vaginal liga- 

 ment; ^7, cartilage of third piialanx; i?4. digital cushion. (After EUen- 

 berger-Baum, Anat. fiir Kunstler.) 



