Self-Myofasical Release (SMR) plays an important part in correcting muscle imbalances.  Basically, it is self-massage.  Massage helps muscles to relax and flushes out congestion which can become trapped.  SMR is the first step toward fixing stressed, tired and sore muscles.  This is a very detailed article, but it does explain it very well.

http://blog.nasm.org/training-benefits/foam-rolling-applying-the-technique-of-self-myofascial-release/