I seem prone to going over badly on my left ankle during descents. Sure it's just a matter of time before I sprain it badly or break it.

I can see it will drain all my confidence in descending fast.

Although it seems to happen when I'm planting the foot harder to slow up a bit, which made me think it might not happen so much if I just loosen up and go fast. Easier said than done though if your ankle's throbbing from a turn already.

Can anyone suggest why it might be or what I might do to prevent it?