dome of the armpit
If you’ve ever doubted the potential power of the armpit, then I encourage you to watch the Still Rings event in mens’ gymnastics. It’s amazing to me that anyone can hold themselves in a cross position by the arms. Truly amazing! This can only happen from the ability to connect the shoulder girdle and upper arm into the core of the body.
The armpit, or axilla, is a doming structure formed by the many muscles that cross the shoulder joint, specifically the glenohumeral joint. It’s anterior wall is formed by pectoralis major, pectoralis minor and subclavius. It’s posterior wall is formed by subscapularis, teres major and latissiums dorsi. It’s medial border is formed by serratus anterior, while the lateral border is formed by the humerus bone. The roof of the axilla is formed by the lateral border of the first rib, superior border of the scapula, and the posterior border of the clavicle. The corocobrachialis and the short head of the biceps brachii cross through the axilla to the corocoid process of the scapula adding to the anterior border. There are many other important structures passing through the axilla including the axillary vein and artery, part of the brachial plexus, many lymph nodes. So one should be both gentle and mindful if palpating these tissues.
I first began to feel this area of my body when working on the Pilates reformer with hands in the straps and arms to the side, I found myself in a very similar position to our male gymnast in the rings — except without the extra gravity and body weight bit. And I realized that we don’t do a lot of pulling in yoga and that this is one of the areas in which we need to supplement our yoga practices. Pulling against resistance. Pulling ourselves through space. Climbing trees. Doing pullups. In my work with yogis, I increasingly find that we struggle to find stability in our shoulder girdles and often hang in the ligaments of our shoulders.
I’ll write more about finding stability in the shoulders through the play of a couple of different muscle pairs (rhomboid/serratus and trapezius/pec minor). But for now, let’s consider the dome in a couple of basic yoga poses.
Down Dog. In table, root the hands to the earth. Feel the knuckle of the hands dropping into the ground as the palm lifts like a suction cup. Feel the forces draw up through the center of the arm all the way to the shoulder socket. Engage the shoulder blades onto the ribcage. Feel and maintain a buoyant lift in the armpits as you lift the knees and draw back into downward facing dog. Feel a parallel between the palms of the hands and the armpits – two light, buoyant, parallel, undulating diaphragms. Resist the urge to sink the chest and fall into the ligaments of the shoulder. Maintain a sense of doming lift in the armpits, as you play with plank, chataranga and arm balancing poses.