http://www.medilaw.tv - Lumbar Spine Pelvis Muscles Pelvic Floor physiotherapy patient education animations. Shows the location and action of the pelvic floor muscles. 1. LEVATOR ANI Lumbar Spine Pelvis Muscles Pelvic Floor physiotherapy patient education animations. DESCRIPTION Levator ani is a broad flat muscle that forms most of the pelvic floor. ORIGIN The pubo-coccygeal part of the levator ani originates from the back of the body of the pubis and passes almost horizontally. The fibres are attached to the sphincter urethrae, the perineal body and the rectum (and the prostate in the male and the vagina in the male). The pubo-rectal part of levator ani originates with the pubo-coccygeal part, but passes below it. The ilio-coccygeal part of levator ani originates from obturator fascia between the obturator canal and the ischial spine. INSERTION The pubo-coccygeal part of the levator ani inserts into the sphincter urethrae, the perineal body and the rectum (and the prostate in the male and the vagina in the male). The pubo-rectal part of levator ani joins with the same from the opposite side and the sphincter ani externus to form a sling behind the anorectal junction. The ilio-coccygeal part of levator ani contributes to the anococcygeal ligament, then inserts into the last two segments of the coccyx. INNERVATION Levator ani is innervated anteromedially by the pudendal nerve and posterolateral by direct branches from the sacral plexus. BLOOD SUPPLY Levator ani is supplied by the inferior gluteal artery. ACTION The pubo-rectal part reinforces the sphincter ani externus, assists creating the anorectal angle, and decreases the anteroposterior radius of the ano-urogenital hiatus. FUNCTION Levator ani forms much of the pelvic floor, which supports the pelvic viscera and contributes to raising the intra-abdominal pressure. Levator ani’s medial fibres are lateral compressors of the rectum, urethra and vagina, assisting with continence. During late pregnancy, the pelvic floor directs the fetal head into the antero-posterior diameter of the pelvic outlet. 2. COCCYGEUS Lumbar Spine Pelvis Muscles Pelvic Floor physiotherapy patient education animations. DESCRIPTION Coccygeus is a triangular sheet that is postero-superior to levator ani. The sacro-spinous ligament is generally regarded to be a degenerate part or an aponeurosis of the muscle. ORIGIN Coccygeus originates from pelvic surface and tip of ischial spine. INSERTION Coccygeus is fused with the sacro-spinous ligament, and inserts into the lateral margins of the coccyx and the fifth sacral segment. VARIATIONS Coccygeus is occasionally absent. INNERVATION Coccygeus is innervated by branches of the ventral primary rami of spinal nerves S3-S4. BLOOD SUPPLY Coccygeus is supplied by the inferior gluteal artery. ACTION Coccygeus supports the coccyx, and pulls it forward after it has been pushed posteriorly during child-birth. FUNCTION Coccygeus forms the posterior and smaller part of the pelvic diaphragm. It acts with levator ani to support the abdominal organs. Lumbar Spine Pelvis Muscles Pelvic Floor physiotherapy patient education animations.