J. Cholewicki, Krishna Juluru, Andrea Radebold, Manohar M. Panjabi, Stuart M. McGill


October 1999, Volume 8, Issue 5, pp 388 - 395 Original article Read Full Article 10.1007/s005860050192

First Online: 26 October 1999

The increased intra-abdominal pressure (IAP) commonly observed when the spine is loaded during physical activities is hypothsized to increase lumbar spine stability.The mechanical stability of the lumbar spine is an important consideration in low back injury prevention and rehabilitation strategies. This study examined the effects of raised IAP and an abdominal belt on lumbar spine stability. Two hypotheses were tested: (1) An increase in IAP leads to increased lumbar spine stability, (2) Wearing an abdominal belt increases spine stability. Ten volunteers were placed in a semi-seated position in a jig that restricted hip motion leaving the upper torso free to move in any direction. The determination of lumbar spine stability was accomplished by measuring the instantaneous trunk stiffness in response to a sudden load release. The quick release method was applied in isometric trunk flexion, extension, and lateral bending. Activity of 12 major trunk muscles was monitored with electromyography and the IAP was measured with an intra-gastric pressure transducer. A two-factor repeated measures design was used (P


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