A back support for use in combination with a chair is provided. The back support may be used to remove body weight of a person from lower regions of the body, including the spine and pelvic region. The back support generally comprises first and second harness supports positionable at an upper region of a backrest of the chair, first and second harness supports being spaced apart and extending generally upwardly from the backrest when positioned at the chair, first and second harness supports each having an upper portion, and first and second harnesses suspendable from the respective upper portions of first and second harness supports, each of first and second harnesses being engageable with the body of the person or being engageable with additional harness structure that engages the body for transferring at least a portion of the weight of the person to the first and second harness supports.