There are some injuries from which you can easily recover. Things like maybe a scratch on your arm or leg are things that are practically inconsequential that the worst things that can leave is a barely noticeable scar. Those injuries are fine and they can be lived with. However, some injuries can cause so much damage to a person that it could change how and who they are within a single moment. That is why there is a need for Functional Capacity Testing, otherwise known as Functional Capacity Evaluation (FCE).
According to the WorkSTEPS website, these standard testing protocols are necessary in order to see if the injured employee is fit or capable enough to return to work or if the given worker needs to be given a new position in order to accommodate the given injury. These injuries are not necessarily confined to physical injuries, even, as they also account for mental or emotional trauma.
Post-Traumatic Stress Disorder (PTSD), for example, is a mental condition that is often sparked by sudden or unexpected trauma which a person could suffer after an intense physical injury. The physical injury might heal, in time, but PTSD attacks the mind and it can be very difficult to work with. There are night terrors that are often prominent in someone who suffers from this condition as well as recurring flashbacks or panic attacks if triggered even by the most seemingly harmless circumstance or phrase. There are other mental conditions that have, more or less, the same effects but this is the most prominent and common scenario in the public sphere today.