3. Gluteal muscles

4. 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.

5. Sup gluteal N Sacral plexus, L4,5,S1.
Passes through greater sciatic foramen.
Supplies gluteus medius, gluteus minimus & tensor fascia lata.

6. Inf gluteal N Sacral plexus, L5,S1,2.
Passes through greater sciatic foramen.
Supplies gluteus maximus.

9. 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.

10. Greater sciatic foramen
Boundaries:
Greater sciatic notch.
Sacrotuberous & sacrospinous ligaments.

11. 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).

12. Lesser sciatic foramen
Boundaries:
Lesser sciatic notch.
Sacrotuberous & sacrospinous ligaments.

13. Structures passing through it
Tendon of obturator internus.
N to obturator internus.
Internal pudendal vessels.
Pudendal N.

14. Structures passing from greater to lesser sciatic notches
N to obturator internus.
Internal pudendal vessels.
Pudendal N.