I have mentioned subtle neck injuries many times. They are rarely found with imaging because, 1. The imaging does not show soft tissue strains. 2. The doctors do not believe there can be anything wrong if there are is not a fracture or visible tear.

But, neck instability can be diagnosed in many ways. If the muscles spam, that can indicate radiculopathy or other irritation of nerves. They are usually not a "Hey Physical Therapist, Fix this." condition. It takes discipline on the patient's part to follow a PT program for an extended period and let the neck heal. No 'I'm just going to play touch football on Thanksgiving then I will rest.' Instead, it takes an 'I am not going to do anything to risk aggravating my neck for 3 to 6 months while I strengthen it by following the PT's orders.'

Working out that part of the body should be about healing, not building strength.

It took me years of discipline and gentle treatment, PT and chiro, to get stability back. But, I still have a neck that requires care. I have crepitus when I move it. But, I don't get the muscles spasms and inflammation I used to get frequently.

There is an old anecdote.
A patient says to the doctor, " It hurts when I do this...."
The doctor responds, "Stop doing that."