Whether you loved or loathed high school geometry, you probably never dreamed that learning about triangles might someday help you protect your back, improve your posture, breathe more deeply, and decrease the wear and tear on your hips.
But it's true: A refresher course on the geometry of triangles can help you understand how to do Trikonasana (Triangle Pose) more easily and reap the benefits from it. The actions in Triangle may seem subtle, but they can have profound consequences. When you're folded sideways into Triangle, you build strength in your torso muscles, which support the weight of your spine, rib cage, and head against the pull of gravity. As you train the muscles around your shoulders to keep your arms in place, you're not only teaching yourself not to slump but also opening your chest so your lungs can expand more fully. And the increased range of motion you eventually experience in your hips means you distribute wear inside the joints over more of their surface, rather than consistently stressing only a small part of the cartilage lining the joint.
The Right Triangle
In the Iyengar tradition that I teach, Triangle Pose consists of straight lines and crisp angles. When you come into it to the right, your spine, right arm, and right leg form an isosceles triangle—and the two most important elements are the straight lines in the legs, arms, and spine, and the 90-degree angle between the arm and the spine.
In the full expression, your spine is parallel to the floor and your arms perpendicular to it. To achieve this elegant architecture, tip your pelvis to the right. Think of your pelvis as a bowl. If the bowl stays upright, when you place your right hand on the floor or on your right shin, your spine flexes laterally up toward the ceiling, lengthening your left waist while shortening your right waist. To allow your spine to flow in a nearly horizontal line, you must tip your pelvis almost 90 degrees to the side.
And to get that full tip, you need flexible hamstrings and hip adductors. Both of these muscle groups originate on the ischial tuberosities, or sitting bones, on the bottom of the pelvis. If your right hamstrings and adductors are short or tight, their pull on the right ischial tuberosity will prevent your pelvis from tipping to the right.
You know you have tight hamstrings if you feel an intense pull in your front-leg hamstrings or inner thigh in Trikonasana, or if you can't put your hand down without bending your torso to the side. If that's the case, try stretching your legs in Supta Padangusthasana (Reclining Hand-to-Big-Toe Pose) before returning to Triangle. Lie with your right side parallel to a wall and a little less than a leg length away from it. Using a strap to hold your right foot, stretch your right leg straight up toward the ceiling and your left leg straight out on the floor. Draw your right leg toward your torso until you feel a moderate hamstring stretch, then breathe and relax into it for about a minute. Next, open your right leg out to the side and pull it gently up toward your head. Adjust your distance from the wall so it supports your foot and you get a moderate stretch on your inner thigh. Again, hold for one to two minutes, and release into the stretch.
Now that you've encouraged length in your hamstrings and adductors, come to a wall to apply it in Trikonasana. A wall is excellent for feedback: It can reinforce the actions in your legs and help keep your hips, torso, head, and feet all in one plane.
With your back to the wall, your feet about four feet apart, your right foot turned out, and your left foot turned in, stand so only your right buttock is touching the wall. If you force your left buttock to the wall, you'll be limited in your ability to tip your pelvis to the right, and it will be hard to keep your right knee properly aligned with the center of your foot.
Once you've set your basic stance, press out through your right leg into the four corners of the foot, as though you're trying to push the mat away from the floor. This will engage your quadriceps to support your right knee. Next, place the web of your right thumb at the crease where your thigh joins your pelvis. Inhale and, as you begin to exhale, push with your right hand so your right buttock slides back on the wall, away from your head. This will initiate the tip of your pelvis to the right and help you maximize the length of your hamstrings and adductors.
When you feel your hamstrings and adductors stretching, stop and put a block under your right hand. When the leg stretch becomes intense, that's a sign you've rotated the pelvis as far as you can. If you continue reaching, you force your spine to flex laterally, and you'll lose the straight line at the top of your triangle.
Instead of grasping for something your body isn't ready for, remind yourself that it takes years to develop the hamstring and adductor flexibility that allows you to put a hand on the floor without laterally bending the spine. Until you can do that, use a block and work regularly on stretching your hamstrings and adductors. Eventually, you'll work your way to the floor without sacrificing the length of your spine.
Stability in Motion
Once you've tipped your pelvis and lengthened your hamstrings and adductors, focus on lengthening your spine. Even with your pelvis tipped fully, the weight of your head and shoulder girdle will tempt you to flex your spine laterally so it bows up toward the ceiling, lengthening the left side of your torso and shortening the right. To avoid this, contract your left flank muscles: the deep lower-back muscle quadratus lumborum and the lateral (closest to the side) fibers of the abdominal obliques. These muscles support most of your torso in Trikonasana; when they contract, they pull the left ribs and pelvis closer together, thus lengthening the right side of your torso. The obliques also help rotate your spine and torso, so your navel and breastbone face straight out into the room, not toward the floor.
Now that your right leg and spine are straight and strong, you can focus on your right arm. When you're standing upright with your legs wide, your arms should create roughly 90-degree angles with your torso. As you lift your arms, try not to lift your shoulder blades; that adds a lot of unnecessary tension to your neck muscles. (Those muscles work hard enough to hold up your head and turn it toward the ceiling once in the pose.) To keep your shoulder blades from rising, turn your palms and elbow creases straight up. When you do this, you engage your lower trapezius muscles and release the upper trapezius—actions that help move your shoulder blades away from your ears and onto your back ribs. Now, holding that scapula position and keeping your elbow creases turned up, turn your palms back down to face the floor.
It's important, though challenging, to maintain this scapula position and the 90-degree angle at your right shoulder. If you pull your right hand back too far toward your right knee, you'll close the angle—and probably shorten your right waist. Also, if you lean on your hand, you'll compress your shoulder toward your spine and create congestion in your neck.
Watch your left arm position, too. That shoulder should also be at 90 degrees, so don't lift your arm up to the ceiling unless you're very flexible in your hamstrings and adductors and can put your hand on the floor with your spine parallel to the floor.
When you combine a long torso with proper shoulder positioning, the line of your spine and the line through your arms form a cross. One way to move into the pose is to maintain that shape as you tip your pelvis sideways and move your spine from vertical to horizontal. Transitioning into Trikonasana in this way helps you practice stability (in the torso, arms, and legs) within movement (of the hips and pelvis). Along with enjoying all the benefits of healthy alignment, you get to taste what it's like to flow through the outer currents of time and change while staying stable and centered on the inside.
A physical therapist and Iyengar Yoga teacher, Julie Gudmestad runs a physical therapy practice and yoga studio in Portland, Oregon. She cannot respond to requests for personal health advice.