1. Dolce JR, and Raczynski, D. Neuromuscular activity and electromyography in painful backs: Psychological and biomechanical models in assessment and treatment.Psychol Bull 1985; 97: 502–520.
2. Hildebrandth H, Van Der Valk M. In: Vink P, Douwes M, eds.The back up: The effects of the back up on the musculoskeletal load during display work. 1990 (unpublished).
3. Bills AG.The psychology of efficiency. New York: Harper, 1943, 5–15.
4. Chaffin DB. Localized muscle fatigue—Definitions and measurement.J. Occup. Med. 1973; 15: 346.
5. De Luca CJ. Myoelectrical manifestations of localized muscular fatigue in humans.CRC Crit Rev Biomed Engineering 1984; 11: 251–279.