The left arm showing that it can hyper extend. My elbows don't even straighten, and neither can my brother's. It's only a problem when I try to bowl.
I built hinges for this and inset them like the Churburg arm harnesses are. In the Churburg link go to the armoury. The site rewards some digging around there, and it's well worth going to the castle if you get the chance. That's where I picked up one of the posters that hangs in my shop. I should give some props to Visigoth for piling on some guilt to get me to build the hinges. I don't make them often, so hinges take me far longer to make than I'd like.