I don't think it's psychosomatic because it mirrors other physical injuries in weight training. There is a threshold beyond which an injury becomes too severe

I don't think it's psychosomatic because it mirrors other physical injuries in weight training. There is a threshold beyond which an injury becomes too severe and requires proper rest, an immobilizer, and physical therapy. It requires a little bit of experience to identify those injuries but below that threshold it's better to soldier through the pain with lighter intensity exercise that works the injured muscles. A safe example is working through delayed onset muscle soreness.