When we have and injury the repeated signals to the brain make the brain more excitable. Repeated pain signals change our brains and is called central sensitization. The changes that occur, to the sufferer, feel as if the pain is getting worse.
Desentisizing exercises help us over come pain. We can change our brain and our response to pain by changing a few things. Breathing exercises are important because slowing the breath resets our nervous system from excitement to a calm balance. The link below is an example of sympathetic breathing :