Have a rider who we've done just about everything for to fix the fold. Everything from helmet to the chest, jumping with no reins over fences to encourage both balance and upper body strength. He's finally grasped the concept of waiting for his horse to put him into the correct position over a fence rather then jumping ahead which was never so much of a problem. Now we're working on the break over or fold, trying to support the upper body more. The crest release is no longer that of a green rider, he knows the proper release, keeping a bit of connection with the horse rather than throwing the reins forward. Great feel, flawless eye. Heel could be a bit better as well as lower leg strength, this is another struggle of his is managing to continue to sink down into the stirrup at the base and over the fence, again I feel out of techniques and explanations. That begin said, does anyone have any tid bits that may have helped you, or that you think could help this rider? Typically the issue is present at 3'3 and above. Great rider though with a lot of heart, hard worker, just think he could use different wording or even a technique that someone else used to help fix the same issue.
The Great White North, where we get taxed out the wazoo
I think of it as "hold your shoulder". Looking up and forward at a designated point in front- encourage him to look at fingers you are holding up or make eye contact can also help. Ensuring the stirrups are really the right length can help, far too many have them too long which weakens the base of support snd makes them have to catch up in the air.
Usually, problems with position over fences relate to a too weak base of support that can be seen on the flat and should be fixed there before the fences go up. Without pictures it's hard to get specific.
Confused, if he is having trouble supporting his upper body over the fence, why is he "past the crest release". That's what it is for-supporting the upper body. No rider is ever past it when they need more security or help supporting the upper body, it's part of a basic tool kit even for elite level riders. It's not about a textbook definition, it's about being secure, getting the best out of the horse and using whatever makes that happen.
Have him grab the mane 3 strides out and stay there 3 strides after landing or add that neck strap. Run him thru low gymnastics that way as well. He can NOT move those hands once he starts.
When opportunity knocks it's wearing overalls and looks like work.
I would say its the approach that needs work. It sound more like he is not starting in the correct position going to the jump. Thats where it looks like a young riders trying to Help their horse get over the fence.
I would work on him sitting "away" as he rides forward toward the jump. Ask him to wait for the jump to come to him and let the horse jump up to him.
But you probably know this
I presume you mean he shoves his crotch forward over the pommel which is indeed jumping ahead of the motion. Telling riders who "crotch rocket" to hold their shoulder makes this habit worse... because then they hold their shoulder all day and shove their crotch to the horses ears.
It is exactly a core strength issue as was stated. How often does he ride? If you're doing 3'3 fences, a rider really needs to be in the tack at least 4x/week. Jumping 3' and up isn't for the part time rider, although I know that is an unpopular notion these days. No mounted exercise in the world is going to help if he's the typical 2x/week adult ammy, unless he's serious about hitting the gym in his down time.
Otherwise I make riders practice the fold at cavaletti n 18" jumps all day until it's rendered to muscle memory... and then hound them mercilessly to retain it at height. That's the only way. Well, that and fitness. Best of luck with your rider.