A mechanism for adjusting vertical seat position using a single extremity and requires no user weight to lower. The mechanism features a seat with an integrated grip for lifting. A spring-loaded latch obstructs the teeth to prevent seat lowering without rotation of a handle. The latch pivots out from obstructing the teeth when lifted. To lower the user rotates the handle to disengage the latch, causing the seat to lower under its own weight. At the desired height, the user releases the handle to permit the latch to obstruct downward movement. A gas spring may counter-balance to reduce overall effective seat weight, making the seat easier to lift while still allowing the seat to lower under its own weight upon rotating the handle. The mechanism for horizontal adjustment couples to the handle, which displaces a cable that disengages a pin allowing the seat to move horizontally on a track.