ohhhhhhhhhhhhh, i was looking at those, i broke my ankle few years ago and re-broke it and its never been the same and i feel these stirrups would help, especialy now that i have a horse with the biggest strides EVER!
tophorse thats why Im looking at them, Im 5ft 5 and my new horse is 17.2hh, huge strides also, and like you I had an injury, although for me it was my shin, and it still aches when I ride for long periods of time.
I think something about the angle is supposed to help too, LOL all sounds very technical!
I have used the Sprenger System4 stirrups for 3 1/2 years now and they are brilliant! I have one hyperflexible ankle and two knackered knees and these enable me to still jump and hunt with minimum discomfort!!
Just a warning first, when I first got my System4's I had problems keeping my stirrups as I was resisting what the stirrups were trying to do!! As soon as I relaxed I could ride in them fine!
Really quite odd, the seem to move and I couldnt rise properly at first as I was trying to stand on my stirrups, but eventually you get the hang of them, and relax your ankles, knees and hips like you should.
I do feel I'm now more secure in my seat for using them