Six weeks into restarting my latest OTTB and we've hit the classic wall: lovely in walk, but the moment we trot he braces and goes giraffe.

What's working so far:

• Lots of walk on a long rein before any trot work
• Ground poles on a curve
• Short sessions, finishing on something he gets right

What's your go-to exercise for teaching a track horse to stretch down into the contact?