Larivière C, et al. - Performing this experimental and comparative study, researchers compared the increase in lumbar stiffness with two potential interventions, actively increasing abdominal muscle activity, either through the abdominal drawing-in maneuver (ADIM) or bracing, vs passively increasing lumbar stiffness using a lumbosacral orthosis (LSO). In 25 healthy individuals, they estimated lumbar stiffness, a surrogate measure of lumbar stability, during 7 trunk perturbation conditions: (1) control, (2) ADIM, (3) bracing at 5% of right external oblique maximal voluntary activation (5% bracing), (4) bracing at 10% of right external oblique maximal voluntary activation (10% bracing), (5) LSO, (6) LSO plus 5% bracing, and (7) LSO plus 10% bracing. As bracing and ADIM were performed at the same overall abdominal activation levels (5% and 10% maximal voluntary activation), they produced comparable lumbar stiffness. Observations revealed the independent effects of bracing and LSO. This suggests that in some circumstances, these interventions could be combined.