This paper reviews issues relating to seats including design for comfort and restraint, mechanics of discomfort and irritability, older occupants, and low-back pain. It focuses on the interface between seating technology and occupant comfort, and involves a technical review of medical-engineering information.The dramatic increase in the number of features currently available on seats outreaches the technical understanding of occupant accommodation and ride comfort. Thus, the current understanding of seat design parameters may not adequately encompass occupant needs.The review has found many pathways between seating features and riding comfort, each of which requires more specific information on the biomechanics of discomfort by pressure distribution, body support, ride vibration, material breathability, and other factors. These inputs stimulate mechanisms of discomfort that need to be quantified in terms of mechanical requirements for seat design and function. New seat requirements need to be based on biomedical science and should include the needs of customers.Older occupants are a growing market segment, and new seating criteria may be necessary to accommodate the size, shape, and needs of older occupants. The criteria should address those people with low-back pain and other disabilities that are a consequence of the aging process.