Movement-based feedback may reduce spinal moments in male workers during lift and lowering tasks



Background and Purpose. To assess if lifting performance can be modified and spine stresses reduced in workers who perform repetitive material-handling jobs in a warehouse environment via a novel real-time, movement-based feedback training protocol. Method. A pre-test/post-test group study design was used with a control group. Data were collected in a warehouse setting and analysed in a university setting. A convenience sample of 22 male warehouse employees was divided equally, based on height and weight, and assigned to either an experimental group or a control group. The experimental group received real-time, performance-based auditory feedback from their calculated moments during lifting or lowering using an electromagnetic tracking system. The electromagnetic tracking system was used to measure the side-bending, flexion and rotation moments during six lifts under four different conditions. A series of repeated-measures analyses of variance (ANOVA) (one between (Group); one within (Time)) was performed on the average maximum moments from six lifting or lowering cycles for all three directions: side-bending, flexion and rotation. Results. There were significant group X time interactions for the side-bending moment (p < 0.05) and the flexion moment (p < 0.05) but not the rotation moment (p > 0.05). Lower moments were found in the experimental group, which received the training and feedback, compared to the control group. Conclusions. Real-time, auditory feedback combined with coaching during lifting or lowering tasks may be effective in the short term (six weeks) in reducing the average maximum side-bending and flexion moments in warehouse workers. Further research is needed to determine the long-term effects of this training protocol on low back injury rates. Copyright © 2006 John Wiley & Sons, Ltd.