Have you ever noticed how hard it is for some students to align themselves in Pincha Mayurasana (Forearm Balance, also known as Peacock Pose)? Their lower backs arch too much, their lower ribs stick out in front, and, try as they might, they can't open their armpits. This could all be due to weak shoulder and trunk muscles, but if they have similar misalignments in Urdhva Hastasana (Upward Hand Pose, see left photo), then the problem probably comes mainly from tightness of the latissimus dorsi muscles.
The latissimus dorsi is the most extensive muscle in the body, covering (if you include its connective tissue) the entire lower back, a large swath of the mid-back, and much of the sides of the trunk before running upward to form most of the outer wall of the armpit. It's a powerful extensor and internal rotator of the arm (that is, when the arm is hanging down, latissimus moves it backward behind the body while turning it inward). This strength is essential for movements ranging from chin-ups to swimming to getting up out of an overstuffed chair. If the latissimus muscles (the "lats") are too tight, they can contribute to rotator cuff injuries by preventing full outward rotation of the upper arm bones (humeri) when lifting the arms overhead (see Lifting the Arms: Part 1). Tight lats also make it virtually impossible for your students to move their arms fully into backbends like Urdhva Dhanurasana (Upward Bow Pose) and Kapotasana (Pigeon Pose). What's more, the same tightness keeps your students from positioning their arms and shoulders properly in Adho Mukha Vrksasana (Handstand) and related poses (especially Pincha Mayurasana), not to mention more basic poses like Adho Mukha Svanasana (Downward-Facing Dog) and Urdhva Hastasana.
Once you see where latissimus dorsi attaches and what it does, you'll understand how it can cause so much trouble. The muscle arises mainly from the thoracolumbar fascia. This is a broad band of connective tissue (like a tendon in the form of a sheet rather than a cord) that anchors the muscle to the upper sacrum, the rear pelvic rim (posterior iliac crest), and the rear spines (spinous processes) of all five lumbar and the six lowest thoracic vertebrae. Latissimus also arises from the sides of the last three or four ribs. From these broad origins it sweeps across the back, upward, around the sides of the body, between the upper arm bone and the ribcage (this is where it narrows to help form the outer armpit), then attaches to the front of the humerus just below the humeral head.
When latissimus dorsi contracts, it pulls the humerus backward toward its origins (in extension) and, due to its path between the arm and the body and around to the front of the humerus, it rotates the bone inward. Since it extends and internally rotates the humerus when it contracts, the way to stretch it is to flex and externally rotate the humerus. Flexion of the humerus means reaching it forward, and the natural continuation of this action is elevation--that is, lifting the arm overhead. As discussed in Lifting the Arms: Part 1, to elevate the humerus freely and safely and prevent it from impinging on the tendon of the supraspinatus muscle (one of the rotator cuff muscles), it is crucial to rotate the bone strongly outward while flexing and elevating it. (Keep in mind that when the arm is overhead, "outward" rotation means moving the outer arm forward and the inner arm backward.). Therefore, healthy arm elevation is the natural stretching action for latissimus. Last month's column (Lifting the Arms: Part 2) explained how to move the arms backward into the overhead backbending movement (like Urdhva Dhanurasana) after reaching maximum elevation. This backward action goes beyond full elevation and, if accompanied by continued external rotation, provides maximum stretch to latissimus dorsi.
Now we can see what happens when a student whose latissimus muscles are tight raises her arms overhead. The muscles limit the arms' external rotation, causing possible rotator cuff impingement, which may create a pinching sensation on the top of her shoulders. When the lats pull taught, they arrest the lift of her arms before they arrive completely overhead. This makes her arms angle forward rather than pointing straight up, creating the characteristic "closed armpit" profile of students with tight lats (see left photo). If the student continues to try to lift her arms higher or move them backward, the tight muscles tug at their origins, drawing her upper sacrum, pelvic rim, lumbar spine, lower thoracic spine and lower ribs up and forward. This is what creates the characteristic arched back and forward-poking-lower-ribs profile of students with tight lats. To sum it all up in a single image, tightness of the lats can produce all of the Pincha Mayurasana misalignments described at the beginning of this column.
What can we do in yoga to help the latissimus dorsi muscle? Although we'll emphasize stretch, bear in mind that in order to be healthy the muscle needs to be strong, too. Asanas that strengthen latissimus include Purvottanasana (Upward Plank Pose), jumping the legs through from Adho Mukha Svanasana to Dandasana (Staff Pose), and certain arm balancing poses, such as Lolasana (Dangling Pose) and Tolasana (Scale Pose).
Now for the stretch. First, let's look at Urdhva Hastasana (see right photo). The necessary arm movements are described in detail in Lifting the Arms: Part 1 and Part 2. Essentially, they boil down to rotating the humeri outward, lifting them high (along with the shoulder blades), and then moving them backward. But in order to get a full lat stretch, as your student takes her arms up and back she must stabilize her pelvis, lower spine, and lower ribcage. This is essential to prevent the origins of her latissimus from being dragged along in the same direction as their insertions, which would negate the stretch. To stabilize the origins, instruct your student to keep her tailbone down and her lumbar neutral as she lifts her arms. She may need to firm the base of her buttocks to do this. Ask her to draw her front lower ribs inward, away from her clothing at first, as she reaches her arms and shoulders fully upward and backward. To give her a little extra lat stretch, you can ask her to temporarily flex her neck, take her chin toward her chest, and draw her breastbone toward her waist as she rotates her arms further and takes them up and back. Remind her not to force, but rather to exhale, release and let go when she encounters tight spots and to back off if she feels pain. Once she senses maximum lat stretch—when her outer armpit and/or side body is stretched as far as it can comfortably go—instruct her to maintain as much of it as she can while she returns her head upright, lifts her breastbone high, and backbends her thoracic spine while moving her arms further up and back. This final lift may bring her lower ribs forward a bit and reduce her lat stretch a little, but it will transform the pose from a complex exercise into a complete asana. Optionally, she can drop her head back, but this may arch her back somewhat, making her lat stretch less intense.
Once your student can perform these actions in Urdhva Hastasana, she can do similar ones in Pincha Mayurasana. First, help her set up her base correctly. Have her fold a sticky mat in two and place it near a wall. Teach her how to carefully measure the distance her elbows should be from the wall: Have her sit with her heels on the wall, legs straight, and mark a spot on the sticky mat that is about two or three inches farther from the wall than her kneecaps. Have her place her elbows at this distance and lay her forearms and palms on the mat with her fingers facing the wall (her fingers will be several inches away from the wall). Make sure that she places her elbows no wider than shoulder width apart. Most students will need to place a block between their hands and/or a belt around their arms to prevent their hands from sliding together and their elbows from splaying out to the sides in the pose. Narrow hands and wide elbows are caused mainly by tight latissimus. These misalignments rotate the humeri inward and thereby shorten the lats. Keeping the hands wide apart and the elbows pulled inward rotates the humeri outward, creating the foundation for an effective stretch. Note that the typical placement of a belt in this pose is just above the elbows, but the instructions below work much better if the belt is on the forearms immediately below the elbows.
Instruct your student to kick up into Pincha Mayurasana, bending her knees until her shins are parallel to the floor and the balls of her feet (but not her heels) rest on the wall. Then ask her to do the following actions in order: Use the arms and shoulders to lift the body as high as possible off the floor. Contract the base of the buttocks to draw the tailbone up toward the ceiling, lengthen the lower back, and draw the front lower ribs in toward the spine. Flex the neck and bring the head between the arms. Continue flexing to lift the face upward toward the breastbone. Lift the breastbone as high as possible away from the face and toward the ceiling. Maintaining all this, lift the body higher while moving the armpits as far away from the wall as far as possible. Then, keeping the arms and trunk where they are, bend the neck backward to return the head to the normal Pincha Mayurasana position (face toward the floor). If possible, take the legs off the wall and balance in this alignment. If done correctly, this method of practicing Pincha Mayurasana is extremely intense, but highly rewarding.
When you are comfortable teaching the actions described above for Pincha Mayurasana and Urdhva Hastasana, you can teach similar actions to help your students improve their trunk and shoulder mobility in many other poses, like Adho Mukha Svanasana, Adho Mukha Vrksasana (Handstand), Urdhva Dhanurasana, and Kapotasana. If you combine these latissimus-dorsi-liberating movements with the humerus- and shoulder-blade-freeing actions explained in the previous two "Lifting the Arms" columns [Part 1, Part 2], you will give your students safe and complete arm elevation, and elevate their practice to a higher plane.
Roger Cole, Ph.D. is an Iyengar-certified yoga teacher (rogercoleyoga.com), and Stanford-trained scientist. He specializes in human anatomy and in the physiology of relaxation, sleep, and biological rhythms.