Gluteal muscles
Iliotibial tract Definition: strong thickened deep fascia on the lat side of thigh. Attachments: from tubercle of iliac crest to front of lat condyle of tibia. Receives insertion of superficial ¾ of glut maximus & tensor fascia lata. Helps in maintenance of erect position by stabilization of the hip on femur & the femur on tibia.
Sup gluteal N Sacral plexus, L4,5,S1. Passes through greater sciatic foramen. Supplies gluteus medius, gluteus minimus & tensor fascia lata.
Inf gluteal N Sacral plexus, L5,S1,2. Passes through greater sciatic foramen. Supplies gluteus maximus.
Sacrotuberous ligament Attached from sacrum, coccyx, PSIS & PIIS to ischial tuberosity. Sacrospinous lig Deep to sacrotuberous ligament. It is the dorsal fibrosed surface of coccygeus muscle. Attached from S5 and 1st Coccygeal vertebrae to ischial spine. Sacrotuberous & Sacrospinous ligaments transmit greater & lesser sciatic notches into foraminae.
Greater sciatic foramen Boundaries: Greater sciatic notch. Sacrotuberous & sacrospinous ligaments.
Structures passing through it Piriformis muscle. Sup glut N and vessels (the only structures above piriformis). Inf glut N and vessels. Sciatic N. N to quadratus femoris (sacral plexus, L4,5,S1). Post cutaneous N of thigh. N to obturator internus (sacral plexus, L5,S1,2). Internal pudendal vessels. Pudendal N (sacral plexus, S2,3,4).
Lesser sciatic foramen Boundaries: Lesser sciatic notch. Sacrotuberous & sacrospinous ligaments.
Structures passing through it Tendon of obturator internus. N to obturator internus. Internal pudendal vessels. Pudendal N.
Structures passing from greater to lesser sciatic notches N to obturator internus. Internal pudendal vessels. Pudendal N.