Here is a link to the Association for Applied Sports Psychology (USA) on using imagery for injury rehabilitation that's worth a read. It gives information and instruction on how to use this technique. In case you are curious here are some links to research by R. Maddison (2011) and Shackell and Standing (2007) showing how it may help strength and injury recovery.
Hypnosis will help you with guided imagery/visualisation and deep relaxation which I offer in clinic sessions. If you are not in the Edinburgh area to visit Mulberry House I can talk you through how to enhance your visualisation/imagery technique by phone or Skype!