7yr old girl, injury to nerve which passes superior- to piriformis & winds around greater sciatic notch. Most likely muscle affected -
Structures passing through greater sciatic foramen.
Piriformis
Above Piriformis

Superior gluteal nerve and vessels

Below Piriformis

Inferior gluteal nerve and vessels
Sciatic nerve
Posterior cutaneous nerve of thigh
Nerve to quadratus femoris
Pudendal nerve
Internal pudendal vessels
Nerve to obturator internus

Superior gluteal nerve supplies gluteus medius and gluteus minimus.
Gluteus medius
Gluteus maximus
Obturator internus
Piriformis