Note the distribution of S2-S4 nerve. The S2, S3, S4 innervation, if damaged at the level of the spinal cord, is most likely to produce incontinence of bladder or bowel. Pain of the vaginal delivery arises from stimuli from the lower genital tract. These are transmitted primarily through the pudendal nerve, the peripheral branches of which provide sensory innervation to the perineum, anus, vulva, and clitoris. The pudendal nerve passes beneath the sacrospinous ligament just as the ligament attaches to the ischial spine. Sensory nerve fibers of the pudendal nerve are derived from ventral branches of the S2 through S4 nerves.... So labour will be painful but the vaginal stretching and the episiotomy may not be. Movement of the leg is mediated by L2-L4.