Hip Flexors is one of the reasons for lower back pain. When recognizing hip flexors for being the culprit for back pain you must first ask yourself this question....... Should I be stretching them or strengthening them? There are 5 muscles that flex the hip. They are: 1) Flex the hip 90 degrees - Tesor Fasciae Latae, Rectus Femoris, & Sartorius 2) Flex the hip above 90 degrees - Psoas Major & Minor & Iliacus. Psoas and Iliacus attach to the lumbar spine and when they are