The sternocleidomastoid mastoid (that survives the dissection) usually atrophies first. This is how you rotate the head. Next is the other muscles in the neck, the semispinalis capitus that is used to pull the head backwards, along with the longissmus. These are rarely felt as they weaken, other than a good "burn" that is constant. The trapezius lasts a bit longer because it is bigger. The levitor scapulae goes and that further compromises the ability to lift the arm to the side as the trapezius hands the motion over the scapular rotation muscles.
If all the small neck muscles in the back towards the side of the base of the skull are always burning, that same fibrosis process is slowing down or impeding the flow of the vertebral artery that supplies the spine and back. With reduced mobility and activity, the main back muscles that keep us standing, the erector spinae start weakening. If ab work has been done in the past, they contract as the sternocleidomastoid muscle does and together they draw our chin and shoulders in, which further strains the erector spinae muscles, which burn horrifficly as they atrophy.
The stages of muscle atrophy are the key. First, is the random spasms/cramps that appear out of nowhere, with adequate hydration/electrolytes. Then spasticity starts setting in as the muscles maintain their contracted state. The neurological system will start sending signals to figure out what is not working. They are felt as little twitches (fasciculations) or when severe, as ants crawling under the skin. They can be very light or as things worsen, become big jerks (dystonia). During this stage, sporadic numbness is felt, at times. The big pain events begin after the spasticity until the muscle has nomfeeling left and then gets bad as the muscle turns to cord.
As the erector spinae muscles weaken, the upper back has to support the entire spine and weakens, too.
I have been told by many doctors to ride it out and not push things but I have proven them wrong. Even corded muscles can be revived. My sternocleidomastoid muscle was nothing but strands, much like tendons. I have a huge mass on the worst side that has been continually growing for 2 years. My romboids were completely gone as was my left trapezius. I have regained a couple of inches of romboid and significant return on the left trapezius, considering where it was.
I have used some intense methods and techniques to try and regain about 60% of the lost muscles. I have found, even with muscles missing, I can build surrounding muscles enough to restore certain ranges of motion and functionality. In 24 months I went from a cumulative 500 lbs in a workout to about 90,000 lbs after a 20 mile bike ride. I have been able to duplicate the results with a stroke recovery patient and someone that was paralyzed for a year. Much of what I do goes against everything I learned about working out.
Not many doctors understand what is going on after radiation. Even the Neuromuscular Department Chair at the university hospital where I was treated doesn't fully understand how I was able to do this. I have consulted with the Head and Neck Rad doctor here to try and prevent the most painful part of this, from about year 2-6 for the ones really suffering intensely.
