Getting your body out of the way of your goals
A primary focuses of all sportspeople is to make sure that their muscles and cardiovascular system are at a very high level of function. There is a lot of expertise out there on this topic, and to be honest I am no expert in this side of athletic performance.
The frame or skeleton on the other hand, is completely over-looked in general.
Let me explain:
If your body is compared to that of a bicycle and cyclist, the person creates the force (muscles) and the frame (skeleton) of the bike transfers the force to the ground so it can go forward.
If that bicycles wheel gets buckled, the wheels start rubbing onto the brakes, making the cyclist have to put more effort and energy into the cycling to get the same result.
This also wears the brakes down quicker. Unbuckle the wheel and you will find that cycling gets a whole lot easier and more enjoyable and the brakes last longer and the ride is more comfortable too.
So the body is the same, if you can straighten out the frame, the muscles don't have to work as hard to get the job done. You get more efficient and your joints take less strain.