As you can imagine, I am lucky enough to meet all kinds of people from all different backgrounds through my work. This is definitely one of the best parts of being a chiropractor.
It so happens that one group of people I have spent a lot of time working with since the very start of my career has been high level dancers. Particularly ballet dancers.
I was spurred to write this post based on a recent encounter with an ex-professional dancer because I wanted to try and share an insight into what goes on in a person’s body when he or she pushes his or her body to the extremes common to ballet.
In short, to try and answer "how on earth is she doing that?!", and "that can't be good for you can it?".
Clearly, high level dancers, like most athletes, tend to start very young. This is an advantage when it comes to developing not just the flexibility, but the extraordinary balance that is required for dance.
While balance training is incredibly good for you, helping to protect against all manner of joint and muscle problems, flexibility training is not always so. This is particularly the case with the spine.
How do they do that?!
One of the advantages of stretching and developing flexibility whilst young is that a person’s bones are still soft. This means that, like clay, they can be moulded through the application of repeated directional stress.
With reference to how far dancers are able to bend backwards, two key adaptations take place in the spine to allow this.
The first is the elongation of parts of the vertebrae in the lower back. This is known as spondylolisthesis. The effect is a forwards movement of one or more segments of the lower back, resulting in a much more acute arch.
Training induced spondylolisthesis is ubiquitous amongst high level dancers. That is to say, without a spondylolisthesis a dancer cannot get to very far.
The second adaptation, much less common, is called a limbus vertebra. Once again, this is a training adaptation to hyper-extension.
A limbus vertebra occurs when the front-upper lip of a vertebra is pulled away from the body of the vertebra. This means it is no longer one piece of bone and, as such, allows for more movement.
So there you have it. To be able to bend backwards like a ballerina, you have to have forward slippage of at least one segment of your spine, and are likely to have a floating bit of bone between two segments of your spine.
It is important to say that neither of these adaptations to hyperextension are as bad as they sound. It is easy to get concerned when talking about changes within the spine, but the reality is that many many people have such changes without ever knowing it.
On occasion, as these adaptations take place they can cause discomfort. And there can be a slightly increased rate of degenerative change associated as well, although this can be hugely offset by increased core stability training.
What about the splits?
Dancers are also famous for being able to hitch their legs up to extraordinary heights and attain very uncomfortable looking positions.
The reason for this is increased flexibility of the ball and socket shaped hip joints.
Flexibility of the hips is unquestionably increased with training, but there is some debate about whether people with naturally shallower, and therefore more mobile, hip sockets go on to become more successful dancers.
The shape of our joints varies from person to person and it is certainly very plausible to think that people who have naturally more mobile hip joints have a head start and are then better placed to succeed when compared to average.
But just like the spine, the bones forming the hip joint will adapt to training, particularly during childhood and adolescence.
Taking ballet as an example, the turn-out position so often used requires the hip to externally rotate. With enough repetition, the hip joint will change shape so that the neutral, resting position of the hip is more externally rotated.
This is often a dead-giveaway of a ballet dancer; when a person’s feet point off to the sides more than straight ahead, you can bet your bottom dollar they are/were a dancer.
This remodelling of the hip does accelerate the degenerative process, speeding wear and tear. However, like most causes of wear and tear, it can be largely offset.
Young dancers should maintain their ability to internally rotate their hips through exercises using this movement. Doing so stops the neutral position of the hip from changing without negatively affecting the ability to turn out. In fact, research suggests that preservation of internal rotation actually helps turn out.
As you can see, high level dance, like most top end activities, places the body under immense strain. But the body adapts. And it is these adaptations that are sought to allow participants to get to the next stage of their development.
Genetics play a part, in terms of the shape of joints and the initial flexibility of connective tissue, but training and hard work are responsible for the most change.
But the hard work does not stop with cessation of high performance. It needs to be maintained throughout life to prevent accelerated wear and tear.
A very important point on eating. Dancers have a higher incidence of eating disorders than the general population. This is particularly important during adolescence and for females.
Low calorie intake (relative to requirements) delays menstruation and keeps bones soft for longer.
Purely in the pursuit of performance, this may sound like a good thing, allowing more adaptive change to happen and perhaps more quickly.
This is probably not the case, and what is associated with low calorie intake is Scoliosis. Scoliosis is a postural change that causes the spine to form an S-shape when viewed from behind. It is very common amongst dancers and insufficient calorie intake is one of the chief causes.
Once present, scoliosis can be very difficult or even impossible to change and can end a promising career.