OF THE MUSCLES. 1 13 



ultimately fixed into the sulcus, behind the great tro- 

 chanter. 



Obturator internus. Origin. From the floor of the 

 pelvis, covering the obturator foramen. Insertion. Winds 

 over the bursal sacro ischiatic notch, by tendon, which joins 

 that of the pyriformis ; to be inserted into the sulcus, behind 

 the great trochanter. 



Gemini. Origins. By tendon, from the sacro sciatic notch ; 

 and from the tendon common to the pyriformis and the ob- 

 turator internus. Insertion. Into the sulcus, behind the 

 great trochanter ; and into the capsular ligament. Action. 

 The gemini would guard the capsular ligament ; the three 

 muscles last named would rotate the head of the femur, 

 pointing the toe of the foot outwards. 



Extensor pedis posterior (Plate 111. 10. 13). Origin. 

 From the outer side of the inferior head of the femur, by 

 tendon ; also by slips of fibre, from the head of the tibia. 



Insertion. Into the coronal process of the os pedis, by 

 long tendon. 



The tendon by which this muscle originates is combined 

 with one which passes to the flexor metatarsi magnus. 

 The tendon by which this muscle is inserted into the os 

 pedis begins about the inferior third of the tibia ; and 

 passes through three annular ligaments ; one above the 

 hock, which is common also to the flexor metatarsi magnus ; 

 another at the inferior of the astragalus ; and a third inferior 

 to the hock, which also binds down the extensor pedis acces- 

 sorius. The accessory tendon joins that of the extensor pedis, 

 about one third down the cannon ; where they meet, some 

 muscular fibres from the last annular ligament become in- 

 serted into them. 



Action. To extend the foot ; aiding also in the flexion of 

 the hock. 



Extensor pedis accessorius, or peroneus {Plate III. 11). 

 Origin. From the head of the fibula ; from the fascial sheath 

 of the flexor pedis ; and the sheath of the extensor pedis. 



Insertion. Into that of the extensor pedis, one third 

 down the cannon. The fibres of its tendon can be traced 

 as low down as the os suffraginis. 



Action. To aid the extensor pedis. 



Flexor metatarsi magnus {Fig 8. 3). Origin. From 



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