222 MYOLOGY, OR ANATOMY OF MUSCULAR SYSTEM 



Front of the great trochanter. Tendon is bound down by a 

 band of capsule of the joint from the iliofemoral ligament; 

 bursa between tendon and tubercle. 



M. Pyriformis. Origin, in pelvis by three digitations 

 from the second, third, and fourth pieces of the sacrum, be- 

 tween and outside the anterior sacral foramina, from the 

 hinder border of the ilium below the posterior inferior spine, 

 and from the great sacrosciatic ligament. Emerges from the 

 pelvis by the great sacrosciatic foramen; inserted into the 

 upper border of the great trochanter. 



May be divided by the external popliteal nerve (high divi- 

 sion of the sciatic); inserted into a capsule or absent. May 

 be a bursa under its insertion. 



M. Obturator Intertills. Origin, deep surface of the 

 obturator membrane, except below; from the fibrous arch, 

 completing the canal for the obturator vessels and nerve; 

 from the hip bone between the thyroid foramen and sacroiliac 

 notch up to the iliopectineal Ime, and internally between the 

 foramen and subpubic arch; from the obturator fascia. Emerges 

 by the small sacrosciatic foramen, changes its direction, and 

 passes around the trochlear surface of the ischium; inserted 

 with the gemelli into the forepart of the inner surface of the 

 great trochanter. It shows four or five tendinous bands on 

 the surface turned toward the bone, which receive pinnate 

 fibers. A layer of cartilage covers the grooves on the ischium 

 and a large sy no vial bursa. Another may be between the 

 capsule and tendon. Henle describes the gemelli (gemini) 

 as parts of this muscle, calling them its outer head. 



The gemellus superior, usually the smaller. Origin, outer 

 and lower part of the ischial spine. Gemellus inferior. Origin, 

 upper part of the tuber ischii below the obturator internus; 

 inserted with obturator internus into the great trochanter. 

 They usually meet at origin beneath the obturator; they over- 

 lap it at the insertion. The superior gemellus may be absent 

 or very small; inferior gemellus is more constant. 



M. Quadratic Fcmoris. Origin, outer border of the 

 tuber ischii, and from the adjacent part of the external surface 

 of the tuberosity; insertion, its fibers pass horizontally out- 

 ward into the quadrate tubercle and back of the femur to 

 the level of the small trochanter. Bursa bet ween it and the 



