Side Stretch Satisfaction
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.
Ideally in Parivrtta Janu Sirsasana to the right side, flexible adductors and hamstrings on the right allow the pelvis to tip to the right, so when the torso bends over the right thigh, it lengthens out over the right thigh, with the right ribs approaching the right thigh. If the tight hams and adductors have "frozen" the pelvis upright, the right torso compresses down into itself during sidebending, which can cause painful pinching in the low back and may contribute to arthritis in the lumbar spine.
Help for Stiffness in Legs and Low Backs
For a student with a tight low back and hamstrings, especially one who has a history of lower-back pain or injury, it's probably best to work first on sidebends while leaving the legs out of the equation. One relaxing way to do this is by sidebending over a bolster or stack of blankets. Ask the student to sit on the right buttock on the floor, with legs folded to the left beside her. Pull the long side of a bolster (flat on the floor) in beside the right hip, and have her lie sideways over the bolster so the right side, between the waist and armpit, will be supported by the bolster. (It's important to support the weight of the torso so the side muscles are relaxing, not contracting.) Bend the bottom arm (which supports the head) and leg while stretching the top arm and leg out in line with the torso, as though the back of the body, top leg, and arm were lined up against a wall. In this position, the pelvis naturally tips to the right and the left waist and ribs are gently lengthening. This gentle stretch is an excellent one to teach to your stiff or injured students.
As your students work toward increasing their side-body flexibility, have them continue practicing poses to improve their adductor and hamstring flexibility. They can accomplish this without risking lower-back strain or injury in poses such as Supta Padangusthasana (Reclining Big Toe Pose) and Utthita Hasta Padangusthasana (Extended Hand-to-Big-Toe Pose), with their top foot supported on a chair or ledge.
How will you know when they're ready to combine the two for Parivrtta Janu Sirsasana? When their flexibility has improved, have them sit on the floor as they would for Parivrtta Janu Sirsasana to the right. Can the pelvis tip a bit to the right? Sitting them up on a folded blanket under the sitting bones will help their chances. If the pelvis will tip a little, they're ready to start working on the pose. I recommend placing a folding chair, with the seat facing the torso, over the right leg. This way, they can reach for the back of the chair with the left hand, which helps lengthen the torso horizontally rather than compressing down. The chair seat can support the head, which will help them relax. With a little preparation and support, you can set the stage for your students to enjoy the benefits of side-stretching sitting poses.