Patent attributes
An unstable user support device designed for mounting on a rotary torso exercise machine has a base or mounting bracket and an unstable user support platform configured for engagement by the user and pivotally mounted on the base for pivotal movement through a limited angular range about a non-vertical pivot axis. The pivoting movement may be a side to side tilting movement. Stops between the base and the unstable user support platform control the amount of pivoting movement. This arrangement provides a degree of instability to the platform, to provide a greater challenge to the user's core muscles in balancing the platform while performing an exercise motion.

