1. Posture and the compressive strength of the lumbar spine;Adams;Clinical Biomechanics,1994
2. American Industrial Hygiene Association (AIHA), 2003. Comments by the American Industrial Hygiene Association regarding OSHA's draft ergonomics draft for the prevention of musculoskeletal disorders guidelines for retail grocery stores. Available (online) http://www.aiha.org/Govern-mentAffairs-PR/documents/ga-ergonomics-retail-grocery-comments-08-18-03.pdf.
3. Spinal shrinkage during repetitive controlled torsional, flexion and lateral motion exertions;Au;Ergonomics,2001
4. Beardmore, D., 1998. The identification and control of musculoskeletal risks to supermarket checkout workers. M.Sc. Dissertation, University of Salford, Manchester, England.
5. Effects of load placement on back muscle activity in load carriage;Bobet;European Journal of Applied Physiology and Occupational Physiology,1984