What It Does
Builds the pelvic flexibility needed to follow canter's asymmetrical swing without bracing at the back of each stride. The space hopper image helps because a rider on a space hopper cannot brace against the bounce — they have to follow it or fall off.
What to Feel
A slight rolling allowance through the pelvis that matches the canter stride. No hard stop at the back of the movement. The hindquarters of the horse passing through rather than being stopped by the rider's seat.