THERE IS NO QUESTION THAT THE THINGS WE THINK HAVE A TREMENDOUS EFFECT UPON OUR BODIES.
—C. EVERETT KOOP, M.D.
YEARS AGO I was teaching Tadasana and suggested that the students in the class imagine a relaxed diaphragm muscle, one that felt “dropped down.” Suddenly a woman ran from class. After class she told me that when she relaxed her diaphragm, she felt the need to vomit. I was surprised at the ferocity of her reaction but not at the reaction itself. Many of us hold tension in the chest and belly. We restrict our breathing and thus our ability to take in life and give it back out. Breathing is the first act we perform at birth, and at death, the final stopping of breath signals our end. Breathing is even more important for the yoga student; the diaphragm muscle is primary in the practice of pranayama. It is integral to and effected by the practice of asana as well, and it is often a part of the beginning of a meditation session, or the very object of meditation itself. For these reasons, understanding the functioning of the diaphragm is critical for yoga teachers and practitioners.
The diaphragm is significant in the body because it divides the largest two cavities: the thoracic and the abdominal. It is the major muscle that drives respiration. It contracts and relaxes rhythmically nonstop twenty-four hours a day, just like the heart muscle, and it never fatigues.
BONES
The diaphragm is attached to the xiphoid process of the sternum and the inner surfaces of the costal cartilages of the lower six ribs (Figure 12.1). The bodies of the first three lumbar vertebrae are also attached to the diaphragm. It becomes obvious, therefore, that asana involving the placement of these bones can facilitate or inhibit the function of the diaphragm.
JOINTS
The facet joints of the thoracic and lumbar spines, as well as the costovertebral joints, all play a part in the mobility of the diaphragm and therefore in the depth and quality of breathing. In order to improve your ability to breathe deeply, these joints must be mobile. Back bending asana, either active or supported, tend to open these joints. Even the practice of Tadasana can help improve breathing by positioning the diaphragm in a neutral position. These joints tend to lose flexibility with age, thus interfering with the excursion of the diaphragm.
12.1 DIAPHRAGM, ANTERIOR VIEW
12.2 DIAPHRAGM, SUPERIOR VIEW
CONNECTIVE TISSUE
At the posterior diaphragm are two tendinous structures called crura. The right crus arises from the intervertebral discs and vertebral bodies of the first three lumbar vertebrae. The left crus arises from the intervertebral discs and vertebral bodies of only the first two lumbar vertebrae. Both insert into the clover-shaped central tendon of the diaphragm.
This central tendon of the diaphragm is where the muscle inserts upon itself (Figure 12.2.) The central tendon is an aponeurosis that is located just distal to the pericardium, the covering of the heart; the fascial tissue of the thorax connects the diaphragm to the pericardium. The fascia of the abdomen also connects the vertebrae, the psoas muscles, and the kidneys to the diaphragm at the muscular insertions. In fact, basically all organs both above and below the diaphragm area are connected to the diaphragm in some way, and thus the act of respiration moves them all.
The diaphragm has several openings to allow for the passage of important structures (Figure 12.2). The biggest three are the opening for the aorta, as it descends from the heart through the thorax to abdomen, where it splits into other structures; the opening for the esophagus; and the opening for the vena cava, which is the vein bringing blood from the lower body to the heart. There are also openings for the passage of nerves and smaller veins.
NERVES
The major motor nerve to the diaphragm is the phrenic nerve (Figure 12.3). Phrenic is related to the word frantic. In Greek, phren has as its secondary meaning “the mind, as the seat of the intellect or the heart as the seat of the passions.”
12.3 PHRENIC NERVE PATHWAY
12.4 DIAPHRAGM AND INTERCOSTALS, ANTERIOR VIEW
12.5 INTERCOSTALS, EXTERNAL AND INTERNAL
The phrenic nerve arises from fibers of the third, fourth, and fifth cervical nerves on both sides of the neck. Therefore there are two phrenic nerves, the right and the left. The left phrenic nerve is actually longer, in part due to the placement of the heart.
MUSCLES
Besides the diaphragm itself, other muscles are involved in respiration. These are the external and internal intercostals and the abdominal muscles (Figure 12.4).
The external intercostals run from rib to rib. They originate from the distal rib of the pair and are attached to the superior rib above it. When the external intercostals contract, they draw the ribs together (Figure 12.5). The internal intercostals arise from the inner surface of the ribs and corresponding costal cartilage and insert into the cranial border of the rib below. When the intercostals contract, they draw the ribs together. But the result of this action is slightly more complicated and is discussed in the Kinesiology of Breathing section in this chapter.
Three other important muscles that aid in respiration are the serratus posterior superior, the serratus posterior inferior, and the quadratus lumborum. The first arises from the ligamentum nuchae, the spinous processes of C7 through T2, and the supraspinal ligament. It inserts into the superior borders of the second through the fifth ribs. When it contracts, the serratus posterior superior raises the ribs to which it is attached.
The serratus posterior inferior originates from the last two thoracic and first two lumbar vertebrae and from the supraspinal ligament. It inserts into the inferior borders of the last four ribs. When it contracts, this muscle counteracts the inward pull of the diaphragm by pulling the ribs outward and downward. The third muscle, the quadratus lumborum, is discussed in chapter 8.
KINESIOLOGY OF BREATHING
When the diaphragm is stimulated to contract by the phrenic nerve, it descends and moves down from its resting dome shape to a flatter one, increasing its circumference as it does so. This contraction creates an enlargement of the pulmonary space, thus causing the air to enter the lungs due to the drop in pressure inside the lungs compared with the outside pressure. This expansion of the lungs is helped also by the adherence of the covering of the lungs to the lining of the thorax. This adherence causes the lungs to be pulled up and out into expansion with the expansion of the bony thorax.
Exhalation begins when the diaphragm ceases contracting and begins to return to its resting position. It is aided in this by the contraction of the internal intercostals and by the elastic recoil of the lungs and ribs. The quadratus lumborum fixes the last rib and holds it down, so when the internal intercostals contract they bring the ribs down toward it, thus helping the body to exhale the breath.
These actions of the intercostals and other accessory muscles of respiration are greatly increased during forced exhalation by the added contraction of the abdominals, as when you are running, to help force air out of the lungs quickly. This action of the abdominals is used in various forms of pranayama that require strong and quick exhalations. The abdominals are not used much during quiet breathing.
EXPERIENTIAL ANATOMY
For Practicing
12.6 TADASANA
Applied Practice 1: The Effect of Tadasana on the Excursion of the Diaphragm
Prop: 1 nonskid mat
Take Care: Stand on a level surface.
STAND IN TADASANA on your nonskid mat (Figure 12.6). Make sure that your spine is adjusted so that all your curves are neutral. Now take a deep breath and notice how easy that is to do. Allow your lumbar spine to flex slightly and try to take a deep breath again. Notice that the second breath is much harder to take and feels incomplete. This is because the change in vertebral position affects the normal excursion of the diaphragm. Remember this connection between vertebral position and diaphragmatic freedom, not only in asana practice but throughout your daily activities as well.
Applied Practice 2: Sama Vrtti Pranayama with Rib Movement
Props: 4 or 5 blankets (or 4 blankets and 1 bolster) 1 nonskid mat • 1 eye bag or eye cover
Take Care: Do not practice this pose if you are more than three months pregnant. Preparing Blankets:
#1: folded to 2.5” x 10” x 28”
#2: folded to 5” x 7.5” x 28”
#3: folded to 1” x 21” x 28” and rolled firmly from its short end
(or 1 round bolster)
#4: folded as for #1 and then rolled to a final dimension of 5” x 6” x 28”
#5: to cover yourself, for warmth (optional)
PLACE BLANKET #1 in the middle of your nonskid mat so the long sides of the blanket and mat are parallel; place blanket #2 where your head will be. Sit on the mat in Dandasana, with the blankets behind you and with blanket #1 pulled in snugly to touch your buttocks. Lie back and adjust blanket #2 so it supports your entire neck and the back of your head.
After you have made sure that your first two blankets are well arranged, roll to your side, sit up, and place the fatter of the two blanket rolls (or a bolster) under your knees, so that it supports your calves and thighs evenly, and place the thinner roll under your Achilles tendons. Cover up with blanket #5 if you tend to get chilly. Lie down and cover your eyes (Fgure 12.7).
12.7 RECLINING SAMA VRTTI PRANAYAMA
Spend the first few minutes relaxing in Savasana: feet falling away from each other, arms out from your sides, palms up. Make sure that your spine is completely and comfortably relaxed, your buttocks are on the floor, and your chest is elevated. Now begin to pay attention to your breath. Just let it be, but be there with it. Gradually begin to lengthen each inhalation and match it with an equal exhalation, so both parts of the breath are sama, or even.
Now begin to use your ribs in this manner. As you inhale, focus on lifting your ribs out to the side; as the exhalation follows, let the ribs drop slowly. Try this for 3 to 5 breaths. For the second part of the breath practice, focus on the ribs moving as a whole, gliding upward toward the head on inhalation and slowly moving toward the pelvis on exhalation. Again focus on this rib movement for 3 to 5 breaths. The last series is to imagine your rib cage getting deeper with each inhalation. That is, as you inhale, let your breastbone lift toward the ceiling and your back ribs move toward the floor for 3 to 5 breaths. As you do these three aspects of rib movement, make sure that there is no strain and that your breath is even at all times.
After completing each of these three aspects, try them all at once as you breathe a soft long breath in and an equal soft long breath out. Try this final part for 5 to 20 breaths. When you are finished, let your breathing return to a natural state but observe the residual effects in your lungs, ribs, and muscles. Lie for a few minutes in relaxation before rolling to the side and slowly sitting up.
For Teaching
12.8 SUPPORTED SETU BANDHASANA
Applied Teaching 1: Supported Setu Bandhasana to Open the Diaphragm
Props: 2 blankets •1 nonskid mat
Take Care: Avoid this pose if you suffer from hiatal hernia, are more than three months pregnant, or have concerns about your head being lower than your chest.
Preparing Blankets:
Fold both blankets to measure 5” x 7.5” x 28”
HAVE YOUR STUDENT place one blanket on her nonskid mat so the long sides of the blanket and mat are parallel. Have her position the second blanket across the first so they form a +. Ask her to sit down on the mat, close to the bottom blanket and lie back over the setup. Her buttocks should be on the floor and her entire spine well supported (Figure 12.8).
Make sure that her head is hanging back a bit and her rib cage is lifted. In fact, this position should cause her lower ribs to flare to the sides. Her arms rest opened out to the side. Spend a moment to help your student be comfortable. This, and the opening of the rib cage, is what make this a back bend. Suggest that she stay in the pose for 5 to 10 minutes. She may enjoy some deep breathing in the pose. To come out, suggest that she roll to the side and sit up carefully using her arms.
12.9 SAVASANA, WITH PROPS
Applied Teaching 2: Observing the Rib Cage in Sama Vrtti
Props: 4 blankets (or 3 blankets and 1 bolster) 1 nonskid mat • 1 eye bag or eye cover
Take Care: Do not practice this pose if you are more than three months pregnant.
Preparing Blankets: Fold and roll your blankets as for Applied Practice 2, in this chapter.
HAVE YOUR STUDENT set up as for Practice 2, Sama Vrtti Pranayama, including the cover over the eyes (Figure 12.9). Once he is comfortable, sit by his side and observe his breathing pattern. Observe the three directions of movement: opening of the ribs to the side, then movement of the rib cage as a whole toward the head and back toward the pelvis on exhalation, and the deepening of his rib cage from top to bottom.
Now suggest that he increase the range of movement in each of the areas, one by one. Once he has tried several breaths in all three areas, if there is a specific movement that is limited, have him practice that movement 10 to 15 times more. After 5 to 7 minutes of observation, have him continue on his own for another 5 to 10 minutes. Then he should lie still for 10 more minutes before rolling to his side and sitting up slowly.
Uddiyana bandha is a lock created in part by the diaphragm. The word uddiyana means, roughly, “to fly up like a great bird.” It should not be practiced by pregnant or menstruating women or until six months postpartum. It is not recommended for those suffering from hypertension or for six months after abdominal surgery.
This bandha is best attempted on an empty stomach, for example, in the morning after evacuation and before breakfast. To practice it, stand up, lean over, and rest your hands on partially bent knees, while keeping your elbows straight.
Drop your head and exhale strongly and completely. Now contract your abdominal muscles as if to draw your belly to your backbone, as you image your lower ribs moving outward slightly. Hold for 3 seconds, then inhale and relax. Repeat several more times. You can practice this bandha at the beginning of your regular asana practice several times a week. It is believed to positively affect the abdominal organs and to move prana, or energy, into the kunda,or vessel, of the core body.