"Ronak Kothari PT, studied Sports Injuries (2014)
Answered July 13, 2018
Well! Sustained injuries are the one which is called chronic injuries in the medical terms.
The injuries when show up, they always come with the structural or functional damage. When you are healing up from the same , how much you get to the pre-injury status of your function is what decided that you have successfully completed your rehabilitation or not. For the same are the professionals known as PHYSIOTHERAPISTS who turn your loss into gain again to your pre-injury state.
If at all the rehabilitation is not fully completed and you get too early to load yourself into your routine or whatever you used to do before the injury, the body adapts differently with pain and some of the function may be lost permanently or until you work on them again. This loss of structural healing and function is called SUSTAINED INJURIES for you." (
https://www.quora.com/What-are-sustained-injuries)