How pain can cause unwanted behaviours

When we have an injury, we move in ways that reduce the pain or the potential of getting pain. The fear of further damage, of compromising the healing, of increasing the swelling and pain, often makes us move very differently. Whereas in the initial stages of an injury, changing our movement behaviours is completely normal, it is maladaptive when the healing time is complete but out of habit and learnt behaviours, we continue to move as though we are injured. Often we are unaware we are moving in an injured way even though it is well after the initial injury has healed. 
Alterations to breathing patterns are perhaps the most common behavioural change that often persist into the future. Shallow apical breathing and excessive accessory muscle use are typical patterns that often persist well after the initial injury. Holding tension in your body, walking with a limp, holding the arm in a protective position are all common persistent behavioural patterns that physios often see in clinical practise. 
The key to overcoming these maladaptive patterns of movement is to firstly be aware you are doing it, and then to use a form of body awareness to alert yourself of these behaviours.  This might include regular attendance to your breathing or walking patterns, the use of visual feedback such as mirrors to alert you to any irregular movements. There is also the need to alleviate any fear of further damage to overcome these persistent patterns. Keeping the tasks and exercises at a comfortable level of effort will ensure that the body maintains the correct patterns. Increase the load and effort and old well established patterns will return.