a user-actuated lifting assist assembly including a telescoping cross-brace comprising an outer tube receiving an inner tube and a gas cylinder interiorly coupled to said inner tube and said outer tube, said cross-brace and said gas cylinder coupled to the first end of the deck frame at one end and an attachment point on said support leg at a second end such that the cross brace and the gas cylinder rotate about the attachment point when the riser is moved between an upright position and a collapsed position, wherein said gas cylinder generates a substantially horizontal extending force when said riser is in a collapsed position and generates an upward extending force when said first end of the riser deck is raised a sufficient amount to rotate the gas cylinder such that the gas cylinder extends generally upward from said attachment point said inner tube of said telescoping cross brace of said user-actuated lifting assist assembly has a first slot and said outer tube has a second slot, wherein said first and second slots align when said portable riser is in said upright position; and said portable riser further comprising: a lifting assist locking mechanism attached to said outer tube and coupled to a riser unlocking means adapted to unlock said lifting assist locking mechanism, said lifting assist locking mechanism comprising a spring-loaded locking pin operatively positioned in an inclined plane member, wherein said lifting assist locking member is moveable by actuating a spring-loaded unlocking handle;

wherein said locking pin is received by said first and second slots when said first and second slots are aligned to lock said portable riser in said upright position; and wherein said inclined plane member is adapted to move said spring-loaded locking pin in an upward direction along an inclined surface when the unlocking handle is pulled by said user retracting said spring-loaded locking pin from said first and second slots when said user operates said riser unlocking means.