502 



THE MUSCLES AND FASCIA. 



In fracture of the shafts of the radius and ulna together the lower fragments are drawn 

 upward, sometimes forward, sometimes backward, according to the direction of the fracture, 

 by the combined actions of the Flexor and Extensor muscles, producing a degree of fulness on 



the dorsal or palmar surface of the forearm ; at 

 the same time the two fragments are drawn into 

 contact by the Pronator quadratus, the radius 

 being in a state of pronation : the upper frag- 

 ment of the radius is drawn upward and inward 

 by the Biceps and Pronator radii teres to a higher 

 level than the ulna; the upper portion of the 

 ulna is slightly elevated by the Brachialis anticus. 

 The fracture may be reduced by extension from 

 the wrist and elbow, and the forearm should be 

 placed in the same position as in fracture of the 

 ulna. 



In fracture of the lower end of the radius 

 (Fig. 324) the displacement which is produced 



is very considerable, and bears some resemblance to dislocation of the carpus backward, from 

 which it should be carefully distinguished. The lower fragment is drawn upward and backward 

 behind the upper fragment by the combined actions of the Supinator longus and the flexors and 

 the extensors of the thumb and carpus, producing a well-marked prominence on the back of the 

 wrist, with a deep depression above it. The upper fragment projects forward, often lacerating 

 the substance of the Pronator quadratus, and is drawn by this muscle into close contact with the 

 lower end of the ulna, causing a projection on the anterior surface of the forearm, immediately 



FIG. 323. Fracture of the shaft of the radius. 



FIG. 324. Fracture of the lower end of the radius. 



above the carpus, from the flexor tendons being thrust forward. This fracture may be distin- 

 guished from dislocation by the deformity being removed on making sufficient extension, when 

 crepitus may be occasionally detected ; at the same time, on extension being discontinued, the 

 parts immediately resume their deformed appearance (see also page 232). The age of the 

 patient will also assist in determining whether the injury is fracture or separation of the epiph- 

 ysis. The treatment consists in flexing the forearm, and making powerful extension from the 

 wrist and elbow, depressing at the same time the radial side of the hand, and retaining the parts 

 in that position by well-padded pistol-shaped splints. 



MUSCLES AND FASCLE OF THE LOWER EXTREMITY. 



The Muscles of the Lower Extremity are subdivided into groups, corresponding 

 with the different regions of the limb. 



ILIAC REGION. 

 Psoas magnus. 

 Psoas parvus. 

 Iliacus. 



THIGH. 



Anterior Femoral Region. 



Tensor vaginae femoris. 



Sartorius. 



Rectus. 



Vastus externus. 



Vastus internus. 



Crureus. 



Internal Femoral Region. 



Gracilis. 

 Pectineus. 

 Adductor longus. 

 Adductor brevis. 

 Adductor magnus. 



Subcrureus. 



HIP. 

 G-luteal Region. 



Gluteus maximus. 

 Gluteus medius. 

 Gluteus minimus. 

 Pyriformis. 



