Effects of back support on intra-abdominal pressure and lumbar kinetics during heavy lifting.

Lumbosacral supports (LSSs) have been used to minimize the risk of lower back injuries. Theoretically, an LSS will raise intra-abdominal pressure (IAP) and reduce loads in the lower back region. This investigation compared three different LSSs with an unsupported condition. Nine males lifted a weighted box four times, once per condition, at 90% of their one-repetition maximum. Conditions were compared in terms of effects on IAP and its relieving force on L5-S1 kinetics. A multivariate analysis of covariance revealed no statistically significant differences among the three LSSs and the nonsupport conditions on the aforementioned dependent variables. This suggests that there is no difference among LSSs in terms of their biomechanical effects on the lower back region and that the use of any LSS does not necessarily afford more protection than a proper lift without one.