As a bodyworker, I see many clients whose main goal is to increase flexibility. They are often ashamed of their poor range of motion, or feel guilty they don't do more stretching. (This is usually right after starting a yoga class.)
They are surprised to hear that I think flexibility and stretching are vastly overrated and often counterproductive. Why is that? In this post I'll talk a little bit about flexibility, stretching and some other movement qualities that I think are more valuable.
First let's define flexibility. Flexibility usually means the extent of a joint's range of motion. For example, imagine putting your foot on a bar, like a dancer. If you can get your leg parallel to the ground that means your range of motion in hip flexion is 90 degrees. If you can get your foot up to your shoulder, you have an amazing 180 degrees and you're ready for Cirque du Soleil. So flexibility describes how far you can move a joint - its range of motion from A to B. But it says nothing about the quality of movement between these two points. This is important because healthy and athletic movement has more to do with quality than quantity.
The vast majority of movements in sport or life take place within normal ranges of motion. Unless you are a dancer, martial artist or gymnast, chances are you already have most of the flexibility you need. For example, runners don't move their joints into anything approaching the end range of motion (although hip extension comes close). Football players, soccer players, tennis players, baseball players, basketball players will rarely display unusual feats of flexibility. You can prove this by looking at a picture of almost any athlete doing almost anything - you will see that you can put any of your joints into the same position as any of their joints. Of course you probably won't be able to obtain this position quickly, powerfully, smoothly, painlessly, accurately, and with the coordinated activity of other joints. But these deficiencies have nothing to do with flexibility. These are issues of strength, power, mobility, coordination, etc.
But isn't more flexibility better, all things equal? Not really. More flexibility is not necessarily good, because it tends to reduce stability, which is very important. Stability means your joints' ability to withstand forces taking you some direction you don't want to go - like into the splits. Children are great examples of huge flexibility coupled with no stability. Their lower limbs can bend into almost any position, which is kind of cool in a way, but it makes them like a rag doll who will fall over when the wind blows. A flexible ankle is more likely to be rolled. A flexible shoulder is more likely to be dislocated. A flexible ball and socket joint might have too much play in it - the ball kind of rattles around in the socket, causing friction, pain and weakness. Imagine a loose wheel on a bike whose tire wobbles from side to side. The tire has great flexibility, but horribly inefficient and unsafe performance. The cure is to tighten the screws so that the wheel turns true. The same can often be true for a joint - some need to be tighter not looser. This doesn't mean that tightness is always better it just means that there is a trade off between flexibility and stability.
But isn't stretching a good way to prevent injury and pain? No. Research makes this point very clear. Study after study has compared the injury rates between athletes who stretch prior to games and those who do not. The studies always conclude that stretching provides no benefit. The studies do show, however, that warming the body up and practicing the moves that will occur on the field will help to prevent injury. This makes perfect sense according to the SAID principle. As discussed in a previous post, the SAID principle means that we will get better at exactly what we practice. In the context of stretching, it means that if we sit on the ground and try to touch our toes, we will get better at sitting on the ground and touching our toes. We will not get better at withstanding the forces that will be applied to our hamstring while sprinting with a soccer ball. In fact, we may get worse. Studies show that stretching will cause a short term decrease in the power required for sprinting, jumping or almost any other explosive sports activity. Stretching effectively puts the muscle to sleep, making it better at stretching but worse at sports.
So why do so many top athletes stretch before games? Good question. There are a few popular explanations. First, many great athletes succeed in spite of, and not because of their training. Second, stretching can be part of a pregame ritual that gets you mentally ready to play (even if its a kind of a waste physically). Third, the trend among pregame warm ups for elite athletes is very distinctly moving away from stretching in favor of activities that actually prepare the body for the movements that will be used in the game. This means "dynamic joint mobility drills" or a "movement prep." I'll talk more about these in my next post. For now, the main point is this. Most movements in sports and life do not require any more flexibility than you already have. To make these movements more coordinated and pain free, work on improving quality of movement, not quantity.