Causes

The muscles most commonly associated with causing low back pain are the quadratus lumborum, the gluteus medius, the gluteus minimus, and the deep hip rotators.

Self-Treatment

1. Get a tennis ball and put it on the floor.
2. Lying face up  on top of the tennis ball, position yourself so that the ball is pushing into the quadratus lumborum (the muscle next to the spine just at waist level).
3. Relax into the ball and take slow deep breathes.
4. Try to relax into the ball more, with each consecutive breath.
5. Allowing the ball to roll, move your body over it until it is positioned at the top portion of the buttox.  (Or you can remain stationary and move the ball with your hand.)
6. Breathe and relax into the pressure.
7. After a minute or so, move the tennis ball an inch or so down the buttock toward the leg.
8. Continue downward, pausing every inch or so, breathing and relaxing on each pause.
9. When you’ve reached the bottom of the buttock, return the ball to the highest point on the buttock where you started.
10. Move the ball out an inch or so away from the spine.
11. Breathe and relax into the ball.
12. Continue outward, inch by inch across the buttock, breathing and relaxing, as in step 7.
13. You can then return to the starting point on the buttock and move the ball in diagonal lines between the two lines that you just finished.
14. *Be sure to go all the way out to the end of the muscle.  (In other words, by the time you finish the outward moving lines, you should be lying on your side.)
15. Change to the other buttock and repeat steps 1 through 14.