Weakness or paralysis of the serratus anterior muscle causes the shoulder blade or scapula to “wing.” Nerve injury as you describe is one possible reason for this problem. Medical reports suggest that the nerve function will return in about nine months. It can take as much as two years before the nerve has recovered.
About 25 percent of the time, the patient doesn’t get full use of the shoulder blade back and the winging persists. Sometimes doctors can operate and help the problem. They can transfer another muscle to that spot to work in place of the serratus anterior. It’s also possible to fuse the shoulder blade to the rib cage. Surgery isn’t done until at least two years has gone by and it’s clear the nerve isn’t going to get any better.
It’s best to work with a physical therapist to keep the muscles around the scapula from freezing up. Of course, the patient is advised to avoid the movement that caused the problem in the first place.