The ways in which we are injured are many and varied. So too is the severity of the injury, but the healing process for all these injuries is much the same. The problem of course, is when the process does not complete. In order to find out where in the process you are stuck, it becomes necessary to investigate how you got the injury, and how the healing process was going before you discovered it was incomplete. Also if you understand HOW you were injured, you may be able to prevent the process from happening again. Accidents happen, and no one is perfect, but many injuries come from not knowing how badly we are hurt at the time.
There is also the knowledge of how to treat injuries, which depends on how you got them (etiology). A neck injured in a car accident is treated far differently from a neck injured by incorrect posture over many years.