You don't see the American crest releases here in the UK, everyone is automatically taught an automatic release from the word go.
The problem you're having with the release is probably that you don't have a strong enough base of support. From what I've seen of US pictures showing the crest release, the fashion is to have over long stirrups so that the leg slips back and the rider then uses their arms and hands for support over the jump. If this is correct of you also, you probably want to take your stirrups up a couple of holes and practice riding in jumping position on the flat. When you can walk, trot and canter in this position without using the reins or the horses neck for support, start back over small jumps. Gradually build up from there.
You want to feel that you are sinking your whole weight into your stirrups and using your ankles and knees as shock absorbers.
You could also try working without reins over small grids (with someone nearby to help in case of trouble) as this will teach you t find your balance and not rely on the reins for support.
Amanda
