In Defense of the Rotator Cuff
This post is being written at the request of a lovely Aussie follower who has suffered multiple rotator cuff tears in the course of her dance life. While not all dancers suffer from rotator tears, it’s a fair bet that almost every dance will run afoul of their shoulders at some point. The following ideas should help you minimize your chances of injury in those moments of potential crisis. Note that while I will give some specific lead or follow examples, all of these should hold mechanically true for both leading and following.
A quick note before anyone jumps up to tell me that their instructor told them to do it differently, I’m speaking here from a biomechanical and injury-proofing standpoint, not an aesthetic or stylistic standpoint. I personally find that solid body mechanics tends to translate to great aesthetics for me, and I try to base my dancing first and foremost on things that I think will allow me to keep dancing for the rest of my life. These are the best safe & effectively connecting body mechanics that I have come up with in 11 years and if I develop or encounter a better idea, I’ll definitely post about it.
The rotator cuff is the group of muscles connecting the top of the upper arm bone (humerus) to the shoulder blade (scapula). The reason these are important is that the shoulder blade is a relatively mobile and therefore unstable joint. The surface of the shoulder joint (glenoid fossa) is essentially a very shallow bowl that has been overfilled with the head of the humerus. This makes the joint very mobile, but also vulnerable to sliding around or out of the socket (one of the reasons shoulder dislocations are far more common than, say, hip dislocations). The muscles of the rotator cuff are all oriented closely around the joint to rotate the humerus in the joint, provide stability, and protect against injuries like dislocations.
Dancing Based on Natural Angle
Based partly on the rigors of modern life, most of us have become habituated to some less-than-natural positions for our arms. The arms-straight-ahead position that most of us spend a lot of time in (driving, typing, etc.) rolls the shoulder in a way that compresses the front of the joint and, over time, tends to make the shoulders stick forward even when our arms are at our side. Many people, either by instruction or habit from daily life, learn to dance with their arms straight in front of them, reinforcing this compression, and putting the shoulder in an unstable position to deal with strong pushes or pulls. I feel that opening the shoulder up to a neutral and balanced position makes it both more stable and far more functional at handling the demands of swing dancing.
To reacquaint yourself with this position, first hold your arms up around belly button height then slowly move them from reaching straight ahead to straight out to the side. As you swing through this range, you should notice that the level of tension in the shoulder lessens as you move towards the middle of the arc, hits a point of minimal tension, and then the tension starts to increase as you continue towards the end of the arc. You should also notice the position of tensions shift as you pass to either side of that middle point. This point of minimal tension is what I refer to in classes as the natural angle of the shoulder. It is the angle at which the rotator cuff is most relaxed and therefore most able to react to various forces. The exact angle varies from person to person but typically falls somewhere between 30-60 degrees from straight out front and places the hands in a position wider than the shoulders.
When I’m dancing, part of protecting my shoulder is that I consider this angle to be home base for how I orient to my partner. I remember as a newbie being taught things like spotlighting or to “square off” to my partner and it always felt a bit forced. I have found orienting myself to my partner based on the natural angle of my shoulder to be far more connected and comfortable and consequently safer for my shoulder. My hand and arm move to follow or lead my partner and I adjust the angle of my body to keep my shoulder in an open, relaxed and ready position. It can be counter-intuitive to the way many of us orient to our hands, but once you get used to it, it should make a lot of sense for your body.
Chest Up, Shoulders Down
The other typical position that can compromise the rotator cuff is the overhead lift of leading and following turns. Many dancers don’t just bring the hand and forearm up when they turn, they also raise the shoulder blade. Lifting the shoulder blade off the ribs puts the shoulder in a vulnerable position by disconnecting it from the support of the ribs. Without the support of the ribs, it becomes much easier for a pull at the wrong time to bend the shoulder into an angle that will injure it. I have found the next two concepts to be exceptionally helpful in keeping the shoulder in a safe position during spins and turns.
Paint the Fence (aka NO ROTATION)
A common stressor that many dancers put on their shoulder is trying to rotate it out as they lift. While I realize it is a fairly common cue, I find the “checking your watch” method of leading turns does not make kinesthetic sense to me. Rotating the arm to look at your wrist forces the elbow above the shoulder blade which then pulls the shoulder up with it. The more the elbow flairs away from the body, the more the shoulder separates from the ribs, reducing both stability and connection.
A far more effective method of raising the arm comes in an approximation of Mr. Miyagi’s paint the fence exercise from The Karate Kid (the original, not the remake). Keeping with the natural angle of the shoulder, the motion of the arm is basically just “Uuuup…, Dooown…” and the torso moves to create the turn.[youtube http://www.youtube.com/watch?v=R37pbIySnjg]
Unlike Daniel-san, for dance purposes you’ll want to let your elbow be loose, relaxed, and weighted so that it stays low as your arm comes up. But notice in the motion of the movie that this is a whole body motion. You can see the muscles of the chest flex and relax with the motion and you should be able to feel them activating. If you try to same “look at your watch” motion, and feel your pecs, you’ll notice they have almost no activation. Keeping the arm rising and falling and making adjustments with the torso rather than the shoulder rotation will put you in a much safer position and typically keep you more connected to your partner (which also helps you be safer). By maintaining the connection of the arm to the torso, you can also effectively lead turns by initiating small rotations from the chest and spine rather than large motions from the arm.
Scapula as Counterweight (or Turns and Trebuchets)
The other issue I often see putting shoulders in harm’s way is the tendency to think that everything needs to go up. People become so focused on their hand that they forget there is a wrist, elbow, shoulder, and ultimately, spine attached to that hand. So if your only awareness is the hand needs to go up, everything else in that chain tends to go with it. Again, the shoulder rises and you are suddenly in the vulnerable position of having your hand above your head with only your rotator cuff actively holding the shoulder in the socket.
What has served me best is to bring an awareness of my shoulder blade and to think of it as a counterweight to the arm, similar to but not quite as unbalanced as the counterweighting found in a trebuchet. When I want my arm to rise, I don’t think about taking my hand up, but rather, I think about initiating by allowing the scapula to slide down (inferior) my back and away from my head. This serves to stabilize the shoulder in several ways. One, it insures that my arm does not come up without my scapula being solidly in touch with my ribs and it additionally eases some of the effort of lifting my arm, meaning my hand goes up with less muscular effort and I have more freedom to adjust in case of emergency. One of the easiest ways to experience this is to stand with your back against the wall and try both lifting your shoulder blade as your arm rises or letting it slide downward as your arm rises. With the downward slide, you should feel more of the engagement in your chest and back and your arm should feel much lighter and floaty than when you lift the shoulder blade with it.
The counterweight idea is not only useful for turns, but can also be applied to protecting the shoulder from collapsing forward when stretching out in swingouts, tossouts, rocksteps, etc. In a stretch where the arm is not going to come up above shoulder level, think of the shoulder blade as a counterweight to the front of the chest and allow the chest to rise and open as the shoulder blade descends. In the inclined pulley illustration, think of M as the shoulder blade and m as the arm. So long as M is weighty enough, it will resist being pulled up and over the top by m. But if the force of m wins out, then the shoulder blade (M) will be pulled up over the top of the pulley and it will all tumble down the slope. By letting your shoulder blade remain weighty when stretching (at a natural angle) it will prevent a lot of potential strains and sprains that can occur from collapsing and hyper-extending the shoulder.
Keep it Personal
There is no one right way to do this. There is a great deal more variability in human anatomy that a typical textbook will not show and as such, there is a great deal of variability in function as well. The safest angle for one dancer may feel very unstable for another and so on. The more you can create ease in your body, the more ready your muscles will be to keep itself in safe and comfortable positioning. Similar to the non-Newtonian frame concept, the more you are in a fluid, rather than rigid, state to start, the more readily you will be able to react both to potential threats and to communications from your partner. In addition, the safer your body position feels, the more it will free up your attention to try more awesome things. Use the above as suggestions to play with your own angles and ways of conceiving of motion and use whether it feels more tense or less tense as the metric for more vulnerable or less vulnerable.