How do you deal with shoulder pain from work computer chair?

Anonymous
We've got the regular office chair with wheels.
I've been at my job for a month & get a really stiff left shoulder.
I move my left arm around every 30 minutes but by the time I have my morning tea break, I can't lift it above my head.
Last week my left arm went numb & it was a bit scary.
I'm still having shoulder pain.
I asked if I could get another chair & a foot rest but they said no.
I don't want to be taking neurofen everyday while I'm in this job.
It's a contract role for another few months
How do you deal with shoulder pain from work computer chair?
5 Opinion