ANTERIOR TIBIAL REGION. 



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leg upon the thigh ; and by taking their origin from below, they balance 

 the pelvis on the lower extremities. The biceps, from the obliquity of its 

 direction, everts the leg when partially flexed, and the semi-tendinosus 

 turns the leg inwards when in the same state of flexion. 



Fig. 132.* 



V Anterior Tibial Region. 



S Tibialis anticu, 



Extensor longus digitorum, 

 Peroneus tertius, 

 Extensor proprius pollicis. 



Dissection. The dissection of the anterior tibial 

 region is to be commenced by carrying an incision 

 along the middle of the leg, midway between the 

 tibia and the fibula, from the knee to the ankle, 

 and bounding it inferiorly by a transverse incision 

 extending from one malleolus to the other. And 

 to expose the tendons on the dorsum of the foot, 

 the longitudinal incision maybe carried onwards to 

 the outer side of the base of the great toe, and be 

 terminated by another incision directed across the 

 heads of the metatarsal bones. 



The TIBIALIS ANTICUS muscle (flexor tarsi tibialis) 

 arises from the upper two-thirds of the tibia, from 

 the interosseous membrane, and from the deep 

 fascia ; its tendon passes through a distinct sheath 

 in the annular ligament, and is inserted into the 

 inner side of the internal cuneiform bone, and base 

 of the metatarsal bone of the great toe. 



Relations. By its anterior surface with the deep 

 fascia, from which many of its superior fibres arise, 

 and with the anterior annular ligament. By its 

 posterior surface with the interosseous membrane, 

 tibia, ankle joint, and bones of the tarsus with their articulations. By its 

 internal surface with the tibia. By the external surface with the extensor 

 longus digitorum, extensor proprius pollicis, and the anterior tibial vessels 

 and nerve. 



The EXTENSOR LONGUS DIGITORUM arises from the head of the tibia, 

 from the upper three-fourths of the fibula, from the interosseous mem- 

 brane, and from the deep fascia. Below, it divides into four tendons, 

 which pass beneath the annular ligament, to be inserted into the second 

 and third phalanges of the four lesser toes. The mode of insertion of the 

 extensor tendons, both in the hand and in the foot, is remarkable : each 

 tendon spreads into a broad aponeurosis over the first phalanx ; this 

 aponeurosis divides into three slips ; the middle one is inserted into the 



* The muscles of the anterior tibial region. 1. The extensor muscles inserted into 

 the patella. 2. The subcutaneous surface of the tibia. 3. The, tibialis anticus. 4. The 

 extensor longus digitorum. 5. The extensor proprius pollicis. 6. The peroneus tertius. 

 7. The peroneus longus. 8. The peroneus brevis. 9, 9? The borders of the soleus 

 muscle. 10. A part of the inner belly of the gastrocnemius. 11. The extensor brevis 

 digitorum ; the tendon in front of this number is that of the peroneus tertius 11 J that 

 behind it, the tendon of the peroneus brevis. 



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