Do you have associated neck stiffness?
Numbness,tingling sensation in arm?
What is your job profile?
Are you taking any medicines?
Have you seen a doctor so far?
i. Originally Yes, but now only occasional short sharp pain if I move the wrong way.
ii. Very occasionally
iv. Business Manager. (No real physical work)
vi. Not yet due to time constraints
Hi,Thanks for providing more information.
As per your description,your symptoms can be related to nerve compression at cervical spine.
Sometimes repetitive strain,muscular overexertion can result in inflammation around nerves and puts pressure on their path causing pain,tingling,numbness sensation.
So you should try massage with muscle relaxant ointment on back of neck.
Also take OTC Advil.
Physical therapy can be advised.
In my opinion,as you are suffering from last few weeks so a consultation of your family doctor/chiropractor,Orthopedist should be considered.
Take short breaks while doing work.
Avoid putting pressure on your arm while sleeping.