Just in case anyone else might have this problem and could benefit from my solution...
During sporadic riding throughout the nasty winter and increasingly regular riding this spring, I've been having very severe pain in my ankles and knees. Every few minutes or so, I've had to drop my stirrups and roll my ankles. Ouch!
So I thought I might try some of the newer, hinged stirrups to see if they would ease my pain. I looked for a pair to borrow locally to try before buying.
In the meantime, I had a lightbulb moment! This winter I started riding in jod boots without laces. I really love not dealing with laces! However, this week I dusted off my laced paddock boots, and what do you know! No ankle or knee pain! Soooo, it seems that I need the "give" provided by the laces in laced boots.
Problem solved (and without spending $ for new stirrups)! Hope this can help someone else!