What are the responsibilities of an injured employee during rehab?

Follow instructions! The biggest mistake i find injuried employes make is to not follow the full instructions. The sooner you can return to full work performance in general the better you will feel. The key is to carefully follow all physical therapy and medication instructions to aid your rehabilitation as best you can. Returning to activites you love without hurting yourself is important for self-worth and healing.
Participate. You need to be an active participant in your rehabilitation. Understand your employer/insurance company is paying you to be off. It is your responsibility to show up at therapy and you doctor visits and be compliant with your home exercises.