A slouch correction device and a method of operation is provided for use in a chair, in which the slouch correction device is predominantly a loose seat cover on which a patient would sit, one or more straps from the seat cover which pass through an opening between the chair back and seat to secure to a separate harness or to form a harness about the waist of a caregiver, such that a care giver is able to pull on the harness to slide the seat cover and patient seated thereon back into an improved, upright posture position, while using free hands to hold the chair in a steady position. The slouch correction device provided with various improvements, including dual side handles for two person lifts, means to keep straps in safe and easily accessed position when not in use, and comfort features on the harness.