It looks like you are anaemic. And also you have to check with your vitamin and calcium, if the bones are weak then automatically the pain gets triggered more as there is less energy during any metabolic activity.
This is cervical pain (neck pain) and that's the reason the pain radiates until the shoulder blades. If you keep ice that would help and along side you can do hot water fermentation. You shall use cervical collar which would help you to reduce the radiating pain ie. Due to the nerve compression.
You have to go for traction and also you can do ift. Please consult the near by therapist for quick relief. Since you have pain for more than 10 years it is suggestible to go for cervical muscle strengthening exercise.
Use collar will definitely be helpful for him to maintain the good posture. And also cervical pillow can be used which might make you to have better posture of the shoulder neck and arm.
Neck tilt: from the sitting position, tilt your head down so your chin touches your chest. Hold this position for 5 second s. Return to the starting position and repeat. Do this five times.
Side-to-side neck tilt. From the same starting position, tilt you neck toward one shoulder, leading with your ear. Hold for 5 seconds and then return to the starting position. Do this five times on each side.
Neck turn. Look straight ahead, then turn your head to one side, keeping your chin at the same level. Do this five times on each side.
Neck stretch. Holding the rest of your body straight, push your chin forward, stretching your throat. Hold for 5 seconds. From the same starting position, push your chin backward and hold for 5 seconds. Do the forward and backward stretch five times each.
If any of these exercises cause severe pain or weakness in your hands or arms, stop right away and talk with your doctor.
give rest to your shoulder,
keep IFT machine in the Physiotherapy department,
avoid doing overhead activities,
don't put your shoulder in same position while working,
give breaks while doing work,
don't put pressure on that area.