The rotator cuff muscles are a popular group. They come up in daily activities, sports, and yoga-related questions. Many of the questions surrounding the location, function, and dysfunction of the rotator cuff muscles are about their involvement in pain patterns. Do a quick google search for “rotator cuff”. You’ll see that the first page of search results is all related to rotator cuff pain and injury. So, why are these muscles frequently implicated in pain and shoulder injury? In this article I explore the function and dysfunction of the rotator cuff muscles. And I explain how that’s related to shoulder pain in yoga practice.
What is the rotator cuff?
The rotator cuff group includes four muscles:
You’ll find these four muscles located around the glenohumeral joint (shoulder joint). All four of them originate from various positions on the scapula. They insert in an arc from the front, over the top, and onto the back of the head of the humerus (upper arm bone). The tendinous attachments of these four muscles combine to drape over the top of the humerus. Together, they form something that looks like an open shirt cuff. The “cuff” comes together where the humerus (upper arm bone) meets the socket of the shoulder joint.
What does the rotator cuff do?
The rotator cuff is at the heart of the movements at the shoulder joint. This is a key part of our anatomy. This muscle group allows us to place our arm, and therefore our hand, in nearly any position. Remember that the glenohumeral joint lives within the larger shoulder complex which includes movements from the scapula and therefore the clavicle. The ball and socket that makes up the shoulder joint is different than the ball and socket that we find in the hip joint. In the shoulder we find a very shallow socket. That structure is great for allowing mobility. In fact, the shoulder joint is the most mobile joint in the body!
Balancing stability with mobility
However, the ball and shallow socket structure in the shoulder is not so great for stability. For that reason, we have the rotator cuff group of muscles. They help us balance stability with the mobility that the shoulder joint is so well known for. You can think of the rotator cuff group as “dynamic stabilizers”. This means that they contribute to stability by changing and/or increasing tension around the head of the humerus. At the same time, they also create movement to help control the location of the head of the humerus. While larger, powerful muscles of the shoulder joint like the deltoids and latissimus do their work, the rotator cuff group assists. But they also direct that movement more specifically to maintain the head of the humerus in just the right position.
To really understand the role of the rotator cuff muscles, it’s important to also understand what they are NOT designed to do. That is the big muscular push and pull arm movements. That job is better done by big powerful muscles like serratus anterior, latissimus dorsi, and even the biceps and deltoids. Using the rotator cuff muscles to do the job of those bigger muscles can lead to shoulder pain and injury, not to mention inefficient movement.
How the rotator cuff gets in trouble
If the balance of tension is off between these four muscles, we can experience pulls, pressure, and pain in various yoga postures or even day to day activities. Additionally, when we don’t fully take advantage of the larger muscles that move the shoulder, the rotator cuff muscles end up overworking. When is this likely to happen? This is very common when we do repetitive motions. It’s also common when we hold postures that require strength from the big muscles like serratus anterior, but we haven’t developed sufficient strength in those muscles yet, or we haven’t trained our body to use those larger muscles properly. In that case, the activity of the small rotator cuff muscles kicks in and tries to take the place of the insufficient strength or training.
Sometimes this happens because the rotator cuff group of muscles find themselves in a place of mechanical disadvantage. That is, they work harder than they should because the big muscles like serratus are not engaged to stabilize the scapula properly. Finally, pain and pressure around the rotator cuff can come up when the balance between other agonist and antagonist muscles is off and that imbalance is transferred to the rotator cuff muscles. If we force our shoulders to do any of these things: repetitive motions, reach farther than is available to us, or use muscles to create an action they aren’t designed to do, we can end up with irritation, dysfunction, pain, or even something like frozen shoulder.
Where we use the rotator cuff in yoga
So, where do we most commonly get interested in our rotator cuff in yoga and why? We often want to know what’s going on with our rotator cuff muscles in postures where they are linked to irritation, pain, or even injury. That comes up most often in postures like chaturanga, upward dog, and downward dog that we repeat many times (especially if we do a vinyasa style practice).
Other postures where the rotator cuff also comes up are when we take the shoulder through a larger range of motion. That happens in twists with a bind (e.g. Marichyasana C) or poses where we reach behind our back (parsvottanasana or pyramid pose). Finally, issues with the rotator cuff sometimes come up when we do arm balances without strength in the places where we need it, like serratus, or when something about our technique is not ideal.
Chaturanga is one posture where shoulder pain often comes up. In our survey research on yoga and injury we found that shoulders were the third most common body areas injured in yoga. When respondents indicated that they experienced an injury in chaturanga, the majority (85%) also reported that it was their shoulder they injured. One likely place that that pain is coming from in chaturanga is the rotator cuff muscles. Why does that happen?
One reason could be that we’re not supporting the shoulder girdle with serratus, latissimus, and the bigger muscles that handle that role. It’s important when we first learn chaturanga that we learn to create support and stability for the shoulder from the right places. If we ask the rotator cuff muscles to do the work of larger muscles, we can run into trouble. And if we repeat an action over and over that requires significant strength, like chaturanga, when we haven’t yet cultivated that strength, we can run into problems.
Upward dog and downward dog
Rotator cuff issues can come up in upward dog and downward dog. This is usually due to some imbalance between the four muscles of the rotator cuff and some additional tension in the shoulder complex generally.
But like chaturanga, you can also experience strain in one or more of the rotator cuff muscles in upward dog and downward dog if you aren’t supporting the shoulder girdle from the big muscles, especially serratus anterior. In upward dog, correcting this might mean lengthening the distance between hands and feet so that you’re not so far forward that you are pushing into the shoulders. Your intention is for pectoralis minor and the lower trapezius muscles to contribute to lifting your ribcage up between the scapulae, which takes some pressure off those small rotator cuff muscles.
In downward dog, you might need to intend a little external rotation of the arms at the shoulder joint to keep the tension around the shoulder joint balanced. This is especially true if you have tighter shoulders and upper chest muscles generally. If on the other hand, you tend to be bendy, you may have acquired a habit of “hanging your ribcage on your shoulders”. That looks like the ribcage falling towards the floor. Repeating downward dog in that way can put a lot of tension on the tendons and ligaments around the shoulder complex, especially the four rotator cuff tendons. You may need to simply engage serratus to support the shoulder joint if this sounds like your experience in the pose.
Poses with large shoulder range of motion
Poses that require a significant range of motion at the shoulder joint can point out imbalances between the muscles surrounding the shoulder. When we do poses like twists with a bind (e.g. Marichyasana C), or reach our hands behind our back like parsvottanasana, we take our shoulder toward the edges of its range of motion. If muscles are especially tight, or agonists are out of balance with their antagonists, then we may feel tension, pull, or even pain, when we do these motions. It’s important to have some patience and move slowly if we have the feeling that we can’t fully take our shoulder into the position that we’d like to. We may need to work with variations of the posture until muscles around our shoulder open more.
Rotator cuff issues in yoga also come up in arm balances, especially handstand. This is for similar reasons to those that I outlined for chaturanga. When postures require strength and stability in the shoulder joint, we need to be intentional about creating that. That’s especially true when they are weight-bearing. This means engaging serratus anterior, latissimus dorsi, as well as some activity from the deltoids and pectoralis major. It also means not repeating too many of the arm balances until you’ve cultivated sufficient strength and stability in the right places. Take the slow road. Be patient while you cultivate a strong serratus anterior. That can prevent the rotator cuff muscles from trying to step in and do the job of the bigger muscles. And that can prevent potential pain and injury.
How do we protect our rotator cuff muscles from irritation, pain, and injury?
Go slowly when building a practice. Don’t do too much too soon, especially when doing repetitive motions that require strength in the big muscles to stabilize the shoulder joint. Cultivate a relationship with the big shoulder muscles, especially serratus anterior. Don’t force a motion. If it doesn’t go easily, look up the chain of muscles to see where the real restriction might be. Work there to increase range of motion.