I'm usually pretty good about resting my wrists and elbows and usually don't have any trouble knitting for hours on end, but things certainly changed last week.  

I couldn't figure out what had changed to cause the problem, when I realized that the recent mixing up I gave my workout was the problem.  I dislocated my elbows a few years ago, and the ten pushups that are a new addition to a part of my routine are apparently way too tough on them.  I feel like a total wuss!  GAH!

I've been abstaining for exercising and knitting, taking anti-inflammatories, and wearing elbow stabilizers for the past few days, and things seem to be sorting themselves out finally.  I'm about halfway through the slowest pair of socks ever for my husband, and it'll be back to the shop after that, depending on the state of the elbow.