Horse had developed sudden onset fixating patella and in fairness, it was probably the worst I've seen. I told her to bring him in. Spoke to vet and we got him on some bute. I gave them tail pulls, (backwards and side to side), pushing onto LH to engage the quads, and backwards walking.
Horse improved well enough to go out after 7 days and is now pretty much sound.
I feel he developed this due to being weak behind, so get all your clients in the habit of these 3 simple exercises and a lot can be avoided.