A seat assembly including a seat frame, an armrest pivotally coupled to the seat frame, a stopper, and an engagement member. The armrest pivots between a use position and a drop down position below the use position in a vertical direction. In the use position, the armrest is configured to support an arm of a user. The engagement member contacts the stopper in the use position to inhibit movement of the armrest from the use position toward the drop down position. The engagement member is configured to deform against the stopper upon application of a predetermined force to allow the armrest to move from the use position toward the drop down position.