230 MYOLOGY, OR ANATOMY OF MUSCULAR SYSTEM 



the ischial tuberosity to the condyle may extend the thigh 

 and rotate in. Gracilis flexes the knee and rotates the leg 

 inward. Adductors and opponens, the gluteals, balance the 

 body in walking. 



(1) Anterior fibers of the gluteal medius (2) and minimus; 

 (3) tensor vaginae femoris; and some say (4) the condylar 

 part of the adductor magnus, rotate the thigh inward. 



THE MUSCLES AND FASCLE OF THE LEG 



There are three groups, as in the forearm; the extensors 

 are on the anterior side and the flexors on the posterior. The 

 number of muscles passing over two joints is less in the leg; 

 no muscle on the anterior and fibular side springs from a point 

 above the knee. 



Fasciae. The aponeurosis of the leg is not continued over 

 the subcutaneous surface of the bones, but immediately blends 

 with the periosteum. It is dense at the upper and front part. 

 Posteriorly it is continuous with fascia lata, and receives 

 accessions from the biceps, sartorius, gracilis, and semitendi- 

 nosus and membranosus tendons. Over the popliteal space 

 are transverse fibers. It gives off intermuscular septa. In 

 front of and on the sides of the ankle the aponeurosis is 

 strengthened by strong bands, forming the annular ligaments. 



The anterior annular ligament is composed of an upper and 

 a lower band. The upper band, ligamcntum annular -e, p. n., 

 is transverse between the anterior borders of the fibula and 

 tibia. The tibialis anticus tendon alone has a synovial sheath 

 under it. The lower band, ligamcntum cruciatum, p. n., re- 

 sembles the letter Y placed on its side, one arm being external 

 and two internal. The outer portion springs from the hollow 

 of the os calcis, forming a strong loop, ' fundiform ligament 

 of Retzius," surrounding the peroneus tertius and extensor 

 longus digitorum. The horizontal and most constant internal 

 band passes to the internal malleolus over the extensor proprius 

 hallucis; and practically beneath the tibialis anticus tendon; 

 the lower band (oblique) crosses both these tendons, and 

 becomes continuous with the plantar fascia on the inner side 

 of the sole. 



There are three synovial sheaths in all a common one 



