i am finding lately that taking a light gripper and holding it closed in an over-crush state, squeezing much harder than force required to close it, and then cycling my arm open and closed with my hand in multiple supinated to pronated and rotated positions really loosens up my elbows.
EDIT: The first rounds I did of this following the apparent injury point, was a quite intense feeling in the tendons and muscle around elbow. It has decreased rapidly doing this. usually do it about 30 seconds each arm wait a few minutes or more and repeat cycle 3 or 4 times a couple times through the day whenever I remember...
Few weeks ago, I think I rapidly overhand curled the weight instead of cleaning it,

. The above movement has really decreased overall feeling of tightness and pain in the elbows since then. Prolly get back on power cleans next week.