M. Flexor Ischiofemoralis (M. ischiofemoralis), [Figs. 16], [17]
T. pallidicinctus
General Description and Relations.—Thick; on lateral surface of anterior part of ischium; posterior end in lateral iliac fossa; deep to Mm. extensor iliofibularis and caudofemoralis pars iliofemoralis; overlapping ventral extrapelvic part of M. obturator and anteroproximal part of M. adductor superficialis (slightly fused to proximal edge of latter); posteroventral corner contacting anteroproximal corner of M. flexor cruris medialis; extreme anterodorsal corner usually overlapped by tendon of M. piriformis.
Origin.—The muscle arises fleshily from a large area on the lateral surface of the ischium extending ventrally to the origin of M. adductor superficialis, anteriorly to the level of the posterior end of the obturator foramen, dorsally to the ventral border of the ilio-ischiatic fenestra and to the depth of the lateral iliac fossa, and posteriorly approximately to the level of the ventral ischiatic tubercle.
Insertion.—The short flat tendon attaches to the lateral surface of the femur immediately posterior to the insertion of M. piriformis.
Innervation.—The posterior tibial division of the sciatic nerve penetrates the dorsal surface.
Individual Variation.—The ventral part of the insertion may be fleshy.
T. cupido
Individual Variation.—None of significance.
P. p. jamesi