LKnative - Posterior femoral cutaneous nerve block 
Posterior femoral cutaneous nerve (red asterix) and its inferior cluneal branches (green asterix). Other nerves: Pudendal nerve (blue asterix), genital branch of genitofemoral nerve (white asterix), superior and middle cluneal nerves (black and magenta asterixs), anococcygeal nerves (green arrow). Dermatomes S2-Co1+ L2.
6 – Anatomy: Perineal innervation from the posterior femoral cutaneous nerve
The posterior femoral cutaneous nerve innervates the postero-lateral part of the perineum and the adjacent part of thigh