Hello Doctor, 5 years ago I was given a flu injection in my left upper arm. When it was injected it was very painful, I could feel the fluid go in and very painful, ever since I have been left with a painful mussel from the shoulder to the elbow with a weakness which gives way when using the arm. I am right handed. I have made an appointment to see my GP but not until Monday. I do not know what I have done in using my arm but at the moment I am in pain when I lift or straighten it. Could it be possible the injection was put into the nerve as this seams it may be possible hence the weakness in the upper arm. I rub in heat cream which does some good not this time as this is the worst it has been. Can you advise me. Thank you. Susan Sorry this so late. I will view your email in the morning. Ps. this weekness does not go away but is always there.