Pain in left arm

My left arm was in pain that i could not sleep the night before.
The reason was simple and clear enough, I was lawn mowing using the plastic thread grass cutter in No 3 Jln Ubin on Sunday. Felt it was normal thou on the day as the arm was shaking when holding something.
But then again never thought that the prolong vibration make the arm to sprain.
Woke up with a headache today and the whole day. Guess the neck and the head was in strain too.