ANTERIOR TIBIO-FIBULAR REGION. 



419 



two strong intermuscular septa, which inclose 

 the Peronei muscles, and separate them from 

 the muscles on the anterior and posterior tibial 

 regions, and several smaller and more slender 

 processes, which inclose the individual muscles 

 in each region ; at the same time a broad trans- 

 verse intermuscular septum intervenes between 

 the superficial and deep muscles in the poste- 

 rior tibio-fibular region. 



Now remove the fascia by dividing it in the same 

 direction as the integument, excepting opposite the 

 ankle, where it should be loft entire. Commence the 

 removal of the fascia from below, opposite the tendons, 

 and detach it in the line of direction of the muscular 

 fibres. 



The Muscles of the Leg may be subdivided 

 into three groups : Those on the anterior, those 

 on the posterior, and those on the outer side. 



ANTERIOR TIBIO-FIBULAR EEGION. 



Tibialis Anticus. 

 Extensor Proprius Pollicis. 

 Extensor Longus Digitorum. 

 Peroneus Tertius. 



The Tibialis Anticus is situated on the outer 

 side of the tibia ; it is thick and fleshy at its 

 upper part, tendinous below. It arises from 

 the outer tuberosity and upper two-thirds of 

 the external surface of the shaft of the tibia ; 

 from the adjoining part of the interosseous 

 membrane; from the deep fascia of the leg; 

 and from the intermuscular septum between it 

 and the Extensor Longus Digitorum; the fibres 

 pass vertically downwards, and terminate in a 

 tendon, which is apparent on the anterior sur- 

 face of the muscle at the lower third of the leg. 

 After passing through the innermost compart- 

 ment of the anterior annular ligament, it is 

 inserted into the inner and under surface of the 

 internal cuneiform bone, and base of the meta- 

 tarsal bone of the great toe. 



Relations. By its anterior surface, with the 

 deep fascia, and with the annular ligament. 

 By its posterior surface, with the interosseous 

 membrane, tibia, ankle-joint, and inner side of 

 the tarsus ; this surface also overlaps the an- 

 terior tibial vessels and nerve in the upper 

 part of the leg. By its inner surface, with the 

 tibia. By its outer surface, with the Extensor 

 Longus Digitorum, and Extensor Proprius Pol- 

 licis, and the anterior tibial vessels and nerve. 



The Extensor Proprius Pollicis is a thin, 

 elongated, and flattened muscle, situated be- 

 tween the Tibialis Anticus and Extensor 

 Longus Digitorum. It arises from the anterior 

 surface of the fibula for about the middle two- 



Fig. 258. Muscles of the Front of 

 the Leg. 



