Got pain, tingling, or numbness in your hands? If you do, you might assume that you've got carpal tunnel syndrome, a condition caused by pressure on a nerve as it passes through your wrist. But when pain and tingling spread beyond the hands and wrists to the arms, shoulders, or neck, the cause may be another, less commonly known condition—thoracic outlet syndrome. TOS is caused by compressing or overstretching nerves or blood vessels far from the hands, near the top of the rib cage. It can develop from repetitive stress and unhealthy movement patterns, like playing a musical instrument for long hours or typing with your head pushed forward and out of alignment with the rest of your spine, or from an injury such as whiplash. Sometimes a skeletal anomaly such as an extra rib can contribute to TOS, but that is usually not the sole cause.
The preferred treatment depends on the exact source of the problem, but many people get relief from exercises that mobilize and realign the neck, upper chest, and shoulders. Although yoga has not been scientifically studied as a TOS treatment, a well-rounded yoga practice, with its emphasis on good posture and a healthy range of movement, provides just the type of physical program that seems to help. A few simple poses added to your everyday routine can help reduce tightness in the neck that, if untreated, may lead to pain, tingling, or numbness in your shoulders, arms, and hands.
The thoracic outlet is the oval opening at the top of the rib cage. Its border is made up of the uppermost ribs, the top of the breastbone (the manubrium), and the first thoracic vertebra. The collarbone, or clavicle, lies just above and in front of this opening. The subclavian artery, subclavian vein, and nerves that serve your hand all cross over or through the thoracic outlet, between the first rib and the clavicle, on their way to the arm. TOS occurs when tight muscles, misaligned bones, or scar tissue near the thoracic outlet squeeze or pull on these nerves or blood vessels hard enough to cause pain, numbness, or other unpleasant symptoms in the hand, arm, shoulder, or neck.
For some, the source of TOS is the compression of nerves or blood vessels as they pass beneath a tight chest muscle, the pectoralis minor. When this happens, poses such as Shoulderstand—which stretches the pectoralis minor muscle by rolling the top of the shoulder blades backward—may help.
Most poses that roll the top of the shoulders back also open space between the clavicle and the first rib, which is another site where nerves or blood vessels often get compressed in TOS. (Be aware that many different medical conditions can cause symptoms similar to TOS, and certain yoga poses may be contraindicated for those conditions. Check with a health care professional before practicing.)
Probably the most important application of yoga for the relief of TOS is using it to loosen a particular pair of neck muscles, the scalenus anterior and the scalenus medius, since they can create or aggravate TOS in several ways.
The scalenus anterior and scalenus medius muscles connect the sides of the neck to the top of the rib cage. The scalenus anterior attaches to the first rib about two inches away from the breastbone, and the scalenus medius attaches to the same rib an inch or so farther back. The two muscles overlap near the neck and diverge slightly as they go down toward the first rib, opening a narrow, triangular gap between them.
The nerves that serve the hand slip through this gap after they emerge from the side of the neck. From there, they join the main artery to the arm (the subclavian artery), as it traverses the cramped passage between the first rib and the clavicle. The main vein that carries blood from the arm to the heart (the subclavian vein) also passes over the first rib and under the clavicle, but it takes an even more constricted path, between the scalenus anterior tendon and the breastbone.
This congested configuration provides plenty of opportunity for the scalenus anterior and scalenus medius muscles to make mischief. Whenever the scalenes contract, they grow broader, potentially putting pressure on the nerves between them. This compression is amplified if the muscles and surrounding fascia are thickened by chronic tightness, or if they go into spasm. If the scalenes are injured by whiplash, repetitive stress, or other trauma, scar tissue may form, which thickens the muscles further and makes them more rigid, and this may also cause nerve compression.
TOS symptoms can also be generated if the nerves get trapped in that scar tissue, so instead of gliding through muscles during ordinary arm and neck movements, the movements cause the nerves to overstretch. And tight scalenes can pull the first rib up so high it pinches the nerves, subclavian artery, and subclavian vein against the clavicle, creating more tingling, numbness, pain, and potentially even discoloration in your hands or arms.
Relax and Lengthen
To relieve TOS symptoms caused by compression or overstretching of the nerves and blood vessels that serve the hand, you'll want to gradually break down scar tissue within the scalenes, create more space between them, and stretch them enough to lower the first rib away from the clavicle. One logical approach, then, is to use yoga to relax, soften, and gently lengthen these two muscles.
To help lengthen and relax the scalenes, use breathing exercises that lengthen your exhalations. You can stretch the scalenes by correcting forward-head misalignment in standing poses, taking your neck and head backward in backbends, or sidebending your neck. It's also possible to modify classical yoga postures, and the instructions in the section "Opening Move" describe how to do this in a modified and supported version of Matsyasana (Fish Pose).
Since both the middle and anterior scalenes connect the side of the neck to the front half of the first rib, you stretch them most directly by simultaneously backbending and sidebending the neck while moving the first rib down and away in the opposite direction. To move the first rib correctly in the modified Matsyasana, you'll use your hands to pull the upper rib cage diagonally downward and away from the direction of neck bend. You'll reinforce the downward movement of the first rib by exhaling firmly to engage the abdominal muscles, the internal intercostal muscles, and other muscles that pull the rib cage down.
The combined backbend-sidebend of your neck in this modified Matsyasana may be challenging, so move slowly and stop if it's uncomfortable. Don't reach your arms out to the sides while your head is back because this could overstretch the nerves that run from the arms to the neck. Also, make sure to center your head before changing sides or exiting the pose.
Fold one or two blankets to make a head support and lay it at the end of a sticky mat. Lay a yoga block, broad side down, on the mat about 4 to 5 inches away from the blankets, with its long side running across the mat. Lay a second block parallel to the first one, about 8 to 10 inches away from it, toward the foot of your mat. This block will be under your sacrum when you are lying down.
Before you enter the pose, reach one hand over the opposite shoulder and move your fingers backward and downward until they feel the ridge of bone at the top of the shoulder blade. This is called the spine of the scapula. Return your hand to your side and sit on the block farthest from the blanket. Tuck your chin toward your chest, lie back over the first block, and adjust its position so it supports the spines of both scapulae. Don't rest your head yet. Place both palms on the left side of your chest with your fingertips just under your collarbone near the sternum and pull your ribs down diagonally toward your left hip.
Keep your chin tucked down and slowly release your neck and head back and to the right at an angle of about 30 degrees (about two inches of backbend for every one inch of sidebend). Rest your head on the folded blanket. You should feel a mild to moderate stretch along the left side of the front of your neck (the left scalenus anterior muscle).
If you feel too much stretch or if your neck bends backward sharply so your chin juts high in the air, center your head, lift it with your hands, and try again with more head support. If the stretch feels too mild, lower the head support or remove it. If you still need more stretch after lowering the support, you may either reposition the block under your shoulder blades so it stands on its narrow edge, remove the block from under your sacrum, or both.
Hold the position for one minute and exhale deeply, contracting your abdomen and trunk to pull your entire rib cage down. Inhale normally, being sure to release the abdominal and trunk muscles. Now turn your head further sideways (about one inch of backbend for every two inches of sidebend) to target the scalenus medius muscle, and breathe in this position for another minute.
Center your head, lift it with your hands, and repeat this sequence on the other side, remembering to draw your ribs down away from your clavicle as you enter the pose. Do both stretches on each side twice. To exit the pose, again center your head and use your hands to lift it, then roll carefully onto one side and continue with your practice.
If you have tight anterior and middle scalene muscles and you do this pose regularly, it could bring you significant relief from TOS and reduce the chances that the condition will return. You're even more likely to relieve the symptoms if you do this pose in the context of a broader yoga practice, which might also relieve thoracic outlet syndrome from other causes, like a tight pectoral muscle or constricted upper-back muscles (which cause the scalenes to overwork to balance the head on the spine). Yoga is no cure-all, but it does offer tools for returning your hands to comfort and health.
Roger Cole, PhD, is a certified Iyengar Yoga teacher and sleep research scientist in Del Mar, California. Visit him at http://rogercoleyoga.com.