The Meerkat standing frame provides postural support for standing and it has a setting that allows the user to experience some weight shifting and balancing (rocking) within a range of movement.
Meerkat dynamic standing frame

Equipment ID: 1199
Category: Standers
Size: Size 3. Maximum user weight is 237.5 lb.s, user height range as measured from the bottom of the foot to the axilla (arm pit) is 33" to 51".
Manufacturer: R82