A seat assembly for releasable attachment between crutches comprising crutches, the crutches comprising a center support and a pair of outer support members. The outer support members further comprise a plurality of opposed hand grip retention apertures. A seat support comprises a seat support pin received in a hand grip retention aperture of the first crutch, a support body engaged by the seat support pin, and a seat engagement pin that engages one end of the seat is attached to the first crutch. A seat retention pin received in a hand grip retention aperture of the second crutch engages the other end of the seat when the seat is deployed. There may be a brace attached to the seat bottom side and the first crutch.