Effect of a pelvic belt on abdominal pressure by various weights and bending angles

Back support belts are one of the important measures for preventing low back pain. One theory attributes the effectiveness of such a belt to the intraabdominal pressure it applies. The purpose of this study was to investigate the effect of a pelvic belt on abdominal pressure when the subject held four different weights at four different bending angles. The subjects of the study were ten male students who did not suffer low back pain. They wore a cuff with a blood pressure meter on their abdomens under the pelvic belt. They held a weight for 5 s slightly above an adjustable stand at a specified forward bending angle. The external abdominal pressure (EAP) was measured 4 s after lifting the weight. The weight was 0, 10, 20 or 30 kg; the angle was 0, 30, 60 or 90 degrees; there were 4 x 4 = 16 trials/subject. As the weight increased (at all angles), EAP increased significantly. However, at 0 kg and 10 kg, EAP decreased as the angle increased; at 0 kg, EAP decreased significantly. Thus, the belt should be effective for manual material handling due to the sensitive response of EAP for low back load. With light weights such as 0 kg and 10 kg, it is better to use the belt at small bending angles than at large bending angles because EAP decreases as the angle increases.