Brief Answer:
Rotator cuff tendonitis or nerve compression syndrome is a possibilty.

Detailed Answer:
Hi

Thank you for asking HCM.

I have gone through your query. Rotator cuff tendonitis or nerve compression syndrome is a possibility. Injury or calcification of rotator cuff tendons of shoulder can give such symptoms. Nerve root compression syndromes from cervical spondylosis also can cause such pain.

A physical examination with orthopaedician will be helpful to rule out the cause. X ray of cervical spine and nerve conduction study will be required to confirm it. MRI might be required if there is any signs of rotator cuff problems.

Muscle relaxants like tizanidine , NSAIDs like aceclofenac and neurotropic drugs like pregabalin will be helpful in such case. Physiotherapy and muscle strengthening exercises also advised.
A consultation with orthopaedician is well appreciated.

Let me know if anything not clear.
I am happy to help you.
Thanks.

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