I am not sure how it works in the UK but, I would think it would be similar, most employees have health and employment insurance, here in the states the state insurance is called Labor and Industries L&I. These insurance cover the cost of job related injuries and time off because of said injury. Your company should be very careful in laying you off because of a job related injury, should it only be for a short time. I would at least get it looked at, because if it is a serious injury you don't want to lose the window of opportunity to claim this as job related.
That being said, I am no attorney nor a doctor or even an expert on work related injury insurance, these would just be some of my concerns if i was in your shoe.
Best of luck.