A good solicitor will keep you informed at all stages in the progress of your case, including arranging for expert opinions (e.g. medical opinions). At some stage, they may advise you that your employer is willing to settle out of court. You will have to take heed of this advice, and make your own assessment of the risk of proceeding to court or accepting an out-of-court award (See How do I deal with an offer to settle my case?).
Note that most claimants wait for an average of three years for a case to be settled.