Hi, Welcome to Health care magic forum.
It appears to be the muscle
twitch, may be due to the subclinical
cervical spondylosis, it also may be due to the defeciency of calcium, or sodium that is why it is going off when stretching.
I advise you to consult an orthopedic surgeon for diagnosis and treatment. You may need to have an M.RI. for confirmation.
I usually prescribe to my patient with such symptoms calcium suppliments, diclophenac sodium till he consults a surgeon.
Take more of green leafy vegetables, pulses, sprouts,and
protein rich foods to avoid such pains.
Wishing for a quick and complete recovery. Thank you.