A fascinating post by Joanne Elphinston brings up the issue of muscle control and relaxation. For the body to move efficiently and beautifully there needs to be coordinated muscle control including appropriate relaxation. Without this, muscles can only partially release resulting in inhibited movement and eventually fatigue. To observe this for yourself try comparing extending your leg behind you with your quadriceps contracted then again with them relaxed; or rotating your trunk with your abdominal muscles first tensed, then relaxed.How far can you go each time?
Often the person affected will read this as tightness and will try to address the problem by stretching - but of course this is futile if the muscle can't relax to allow the movement. Aggressive stretching can end up being counter productive as it may trigger the stretch reflex in self protection.
One answer is to practice self awareness by consciously contracting and then releasing different muscles in turn, maybe beginning at the neck and then working down towards the toes. This is a common relaxation exercise but you can practice with individual muscle groups whenever you like. Another is to practice seeing how minimal an effort and how few muscles can be used for a movement such as turning the wrist, raising the arm or rotating a leg. Practice the movement, observe which muscles you are activating, think if you really need all of them and then try again. An example is raising your arm up to shoulder height in front of you; are your shoulders remaining relaxed or are you hoisting with your whole shoulder? Practice the movement slowly and observe any changes as you focus on allowing smooth, relaxed movement.
Joanne observes the importance of rapid and effective release of muscle tension in generating power and preventing injury; just as important as rapid and appropriate muscle recruitment. I have observed in my own clinic practice that there is more often an issue around 'letting go' of muscles rather than the ability to recruit.