The quadratus lumborum is a large muscle that makes up most of your middle and low back. You have one on each side of your back. You use this portion of your back when you bend over to the side and pick something up, states the Sports Injury Clinic website. You also activate your quadratus lumborum when you sit, stand or walk. Keep this muscle healthy with exercises that focus on stretching and strengthening.
The Sports Injury Clinic says that the large, flat quadratus lumborum begins in your middle back, attaching to your lowest rib and the vertebrae of your low and middle back. The muscle ends where it attaches to your hip bone, or iliac crest. The Loyola University Medical Education Network indicates that it has two muscle functions: to hold your lowest rib steady as you breathe and to flex the body's torso to each side of the body.
To stretch your quadratus lumborum, stand with your legs straight and your feet together. Raise your hands above your head with straight arms. It is important to keep your arms straight as you stretch them slightly to the right side of your body, bending slowly from your hip, says the Moving to Stillness website. At this point, you should feel your left quadratus lumborum stretch. Hold this position for 30 seconds and then switch to the other side. Repeat this stretch for three repetitions on each side of your body.
You can strengthen your quadratus lumborum muscle using the "side plank" exercise. Lay on the floor on your side. Place your hand on the floor under you and straighten your arm, raising the top half of your body off the ground. You can raise the other arm straight over you, says the Yoga Journal website, or let it rest on your side. Keep your legs straight, letting the lower half of your body rest on the side of your bottom foot. To hold this side plank position, you will have to engage most of your core muscles, including your quadratus lumborum. Hold this position for one minute and then repeat on the other side.
Yoga poses known as "cow" and "cat" are both muscle stretching and strengthening exercises for your quadratus lumborum. Come to the ground on your hands and knees with your hips bent to 90 degrees and your torso parallel to the ground. The Yoga Journal website shows that you should round your back until you look like a cat stretching. Gently hold this rounded back position for about five seconds and then come back to the neutral starting position. Next, flex your low back and hold this position for about five seconds. You can repeat these alternating movements for up to one minute total.