Last time I said that nerves often recover from compression or bruising. Incidentally, I didn’t mention that stretching can damage a nerve. That’s because I was only talking about things that pressed on nerves. A bad break or dislocation can do this kind of harm. Pulling on a newborns arm during an awkward delivery is another well known injury. Moving on though, I thought I’d go into a bit more detail about the process of recovery, which involves making the distinction between two sorts of nerves.
These convey sensation recover more quickly than motor nerves, which tell a muscle to contract. It can be many months for either to fully recover. Notice the word can! A lot will recover in just a few weeks or months. It all depends on the severity of the injury. These are the ones that might give you the numbness or pins and needles when affected.
Nerves re-grow slowly!
– just millimeters per month – and as long as the myelin sheath covering them is still intact. In the simplest terms this sheath is like an insulator which prevents electrical signals going along the nerve from flying around in a disorderly fashion. If that sheath isn’t whole then the re generating nerve ends up going nowhere & end in a knot or scar of painful fibres that can get very painful. This is a neuroma.
If you’ve got a problem here you’ll feel weakness. A muscle has lots of individual fibers. And each of these has a nerve controlling it. This means that an injury may not affect all the nerves and fibres in a muscle.
But here’s the thing: if fibres don’t receive any signals from their nerve for a long time, eventually they shrink when the electrical connection point between nerve and fibre dies away. No connection, no signal! If that happens to enough fibres, then the remaining undamaged part of the muscle will have to work even harder, which may mean that it gets sore or tired after activities which caused no issues before the injury.
In cases where a motor nerve is not showing sufficient signs of recovery after several months surgery is sometimes an option to re establish a connection & prevent permanent muscle loss.