Most people who practice yoga believe in its inherent ability to produce balance in the body, mind, and spirit. Although yoga is a wonderful and transformative practice, there is one aspect of asana that is surprisingly not very balanced. In fact, it's likely to create an imbalance that can lead to physical injury.
If we examine yoga’s asanas through the lens of anatomy, we can see that some shoulder muscles are significantly strengthened through asana while others are hardly strengthened at all.
The term “balance” encompasses a range of experiences from the spiritual to the psychological to the physiological state of being balanced in physical space. But the type of balance I’m discussing here is the functional muscular balance of your shoulders. Although we’re often taught that yoga is a completely balancing practice for the physical body, if we examine yoga’s asanas through the lens of anatomy, we can see that some shoulder muscles are significantly strengthened through asana while others are hardly strengthened at all. This muscular imbalance sets us up for physical harm and injury in the long term.
Luckily, our bodies constantly adapt to the loads placed on them, so this muscular imbalance is not irreversible. But an awareness and understanding of the issue is the first step toward shifting our shoulders to an optimally healthy, balanced state.
The Shoulder Strength Imbalance in Yoga
In order to comprehend how yoga could create a muscular imbalance in the body, we need to understand two opposing anatomical actions: shoulder-pushing movements and shoulder-pulling movements.
Shoulder-pushing movements take place when you use your arms to push an object away from your body. Picture pushing on a heavy door in order to walk through a doorway, or pushing a vacuum cleaner forward as you clean your living room. Although a wide variety of muscles participate when we perform shoulder-pushing movements, we'll focus on the main players responsible for the action. When you push an object away from you using your arms, the muscles doing the majority of the work are the pectorals (the muscles of the chest), the anterior deltoids (located on the front of the shoulders), the triceps (the muscles lining the back of the upper arms), and the serratus anterior (spanning from the scapulae to the sides of the rib cage). The relative engagement of each of these muscles will differ depending on the angle of the arms and the relationship of the movement to gravity, but you can picture these four main muscles as your collective “pushing” muscles.
Let’s look at some examples of shoulder-pushing movements that commonly occur in our yoga practice. We don’t have objects like doors or vacuum cleaners to push in yoga, but we do have a large surface that we push on repeatedly: the floor underneath our yoga mats. Plank pose is a perfect example of an asana in which we push this surface away with our arms. A helpful way to picture the shoulder action here is to imagine what would happen if you weren’t working your arms in this pose. If you let go of all effort in your arms, your elbows would bend under your weight, and gravity would cause your body to collapse to the floor (not an appealing image!). Instead of collapsing to the floor, though, you press the floor away by contracting your shoulder-pushing muscles (your pecs, anterior deltoids, triceps, and serratus anterior) to keep your arms straight and to allow your body to hover over the floor.
Other examples of shoulder-pushing movements in yoga include adho mukha svanasana (downward facing dog), chaturanga dandasana (yoga’s push-up pose), adho mukha vrksasana (handstand), bakasana (crow pose), and vasisthasana (side plank).
In contrast to pushing movements, shoulder-pulling movements occur when we pull objects toward ourselves. Think of pulling a stubborn weed out of the ground, or pulling strongly on your dog’s leash as he tries to chase after the squirrel he so desperately wants to catch. When we perform shoulder-pulling movements like these, the main muscles that contract are what are often called antagonist (or opposing) muscles to the shoulder-pushing muscles. These include the rhomboids and middle trapezius (located on the upper back between the scapulae), the posterior deltoids (located on the back of each shoulder), the biceps and the brachialis muscles (the muscles that line the front of each upper arm), and the latissimus dorsi (otherwise known as the "lats"—the wide, broad muscles of the back). Again, depending on the angle of the arms and one’s relationship to gravity, the relative amount that each of these muscles works will differ. But consider this your general group of shoulder-pulling muscles.
In yoga, we don’t have the equivalent of the stubborn weed or the excited dog to pull against, and there are simply no shoulder-pulling movements available to us in our practice.
Based on what we learned about shoulder-pushing movements in yoga, can you think of some traditional yoga movements which involve shoulder-pulling? Remember that in order for a yoga pose to fall appropriately into this category, it must involve pulling something toward you with your arms. Which poses require this? Can you think of any? If you've guessed this to be a trick question, you are correct—good job! The truth is that there are no objects that we pull toward ourselves in yoga. Traditional yoga involves only our bodies, our yoga mats, the floor, and the various props that we use for support in our poses (but not for pulling toward us, against resistance). In yoga, we don’t have the equivalent of the stubborn weed or the excited dog to pull against, and there are simply no shoulder-pulling movements available to us in our practice. When we combine an abundance of strong shoulder-pushing movements with no complementary shoulder-pulling movements, a functional strength imbalance is the natural (or unnatural) result.
But just to be clear, this apparent lack of pulling movements in yoga is not a shortcoming of the practice or an oversight in any way. It’s simply the reality of a movement practice that is spent entirely on a yoga mat on the floor. But when yoga is described as a balanced and complete long-term health and wellness practice, many practitioners choose it as their main form of physical exercise. To that extent, yoga may actually detract from their goals.
Thankfully, there is an abundance of ways to restore our “yoga shoulders” to true functional balance, although it does require us to broaden our movement repertoire beyond the borders of traditional yoga. Stay tuned for part two of this article series, which will be full of creative suggestions for addressing this shoulder strength imbalance—both on and off the yoga mat!