Low back pain can be very common in pregnant females. It is estimated that between 50 and 80 % of females will experience low back pain during their pregnancy. The incidence of pain is increased with pre-existing low back pain. The cause of the pain is straightforward; as women gain weight due to the fetus the mechanics of her body changes. The stress placed on the lumbar spine (low back) is increased as body weight increases. Weight gain increases the lumbar lordosis (the lumbar spinal curve) thus placing more stress over the posterior joints of the lumbar spine (facet joints/see Lumbar Facet Syndrome).
This causes muscle spasm to the erector muscles, and places an increased stress over the lumbo-sacral region (where the lumbar spine articulates with the sacrum). The pain may be reduced throughout the pregnancy with simple yet effective exercises that help improve the strength of the lower abdominal muscles with posterior pelvic tilts. Stretching therapy, myofascial release and joint mobilization to the lumbar spine has also been shown to help relieve symptoms.