Do you know, where is quadratus lumborum?

Sitting in a narrow, confined space, such as a plane seat, car seat, or office cubicle, can leave you feeling like you've been wearing a straitjacket or full-body cast. You may long for some twists and sidebends to loosen up your spine and torso. But while sitting sidebend stretches may feel great to experienced yoga practitioners and teachers, beginners and stiffer students may struggle to find any enjoyment in them—and they may in fact strain or injure their low backs in the attempt. As a teacher, your understanding of these poses and their benefits can help you motivate students to work appropriately on these asanas, avoid injury, and appreciate their benefits.

Sidebending poses include Parighasana (Gate Pose) and seated forward bends such as Parivrtta Janu Sirsasana (Revolved Head-to-Knee Pose) and Parivrtta Upavistha Konasana (Revolved Wide-Angle Seated Forward Bend). In these positions, the torso bends sideways, which is also called lateral flexion. For example, in lateral flexion to the right (Parivrtta Janu Sirsasana to the right), the left side of the torso stretches and lengthens, while the right side of the ribs and waist shorten. Utthita Trikonasana (Extended Triangle Pose) and Utthita Parsvakonasana (Extended Side Angle Pose) aren't true side-stretching poses because you're working in them to keep length in both sides of the waist and ribs.

Side-stretching poses lengthen the muscles between the ribs and pelvis, including parts of the low back, and open the sides of the rib cage, improving rib cage mobility and the expansiveness of the lungs, which makes breathing easier in all situations, including aerobic activities and pranayama. In sidebends where an arm stretches overhead to reach for the foot, the latissimus dorsi muscle, which extends from the back waist to the armpit, will also stretch.

The All-Important QL

One of the most important muscles stretched during a sidebend is the quadratus lumborum (QL). It sits deep in the back of the waist, attaching to the top of the back pelvis and running up to the lowest rib in the back. When it contracts, it pulls the bottom rib and the pelvis closer together. In standing, the left QL hikes the left pelvis and leg up away from the floor. When you do Trikonasana (Triangle Pose) to the right, it is the strength of the left QL contracting to support the weight of your torso (pulling the left ribs and pelvis toward each other, minimizing sidebending to the right and keeping length in the right waist). The QL can become short and stiff if you regularly spend long hours sitting in chairs, and it can become tight and painful, and even go into spasm, with lower-back and sacroiliac injuries.

In theory, it's a good idea to regularly practice sidebends to keep the QL, latissimus dorsi, and rib cage supple and flexible. However, tight hamstrings and adductors (inner thigh muscles that pull the thighs together) can throw a wrench into this theory. That's because these leg muscles attach to the sitting bone (ischial tuberosities) and pubic bone, and when they're tight, they limit the ability of the pelvis to move, which "freezes" the pelvis in an upright position.
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