Make Pain Your Friend
Pain is your body’s way of letting you know that something is wrong. Stay away from painkillers before your workout so you can listen to your body. If your injury site hurts while you are working out, you are doing more harm than good.
It can be hard on the ego to take your exercises down a notch, but that is exactly what you need to do when returning to workouts post-injury. Either choose an exercise that is less challenging than the exercises you did pre-injury or choose to limit the weight and range of motion of the exercises.