I started my bike commute for this year yesterday, and after I got to work, my elbow hurt all day. It still hurts a bit today, I didn't ride in because of the pain.

This isn't my 1st ride of the year. I mountain bike and have been riding my trainer. I have never had this problem.

My ride to work was only 17 miles, so not too far, but my guess is I may have had my elbow locked out most of ride because of the pain. Is this correct, and anything I can do to prevent this in the future.