Investigation of select ergonomic interventions for farm youth. Part 2: wheelbarrows.

Previous research has provided evidence that farm youth performing farm chores may be at risk of developing a low back musculoskeletal injury. In order to reduce these risks, effective interventions for reducing the stressors that cause the injuries are needed. The objective of the current study was to investigate alternative wheelbarrow styles as an intervention for youth working to transfer material on the farm with respect to trunk motion and perceived exertion. A lumbar motion monitor was used to capture three-dimensional trunk kinematics while several wheelbarrow tasks (e.g., pushing, pushing over bump, and dumping) were performed by youth. Ratings of perceived exertion and comfort of use were also assessed. Results indicated a reduction in the sagittal trunk flexion and velocity was achieved by adding a push bar to the handles, in combination with three-wheels, or utilizing adjustable handles. However, these alterations had little impact in the predicted low back disorder risk levels. Additionally, the youths' perceptions of risk and exertion levels were greater for these alternative wheelbarrows than for the regular wheelbarrow. Therefore, the mismatch between perception and kinematic response will probably affect usage of the alternative wheelbarrows. While the results indicate that alternative wheelbarrow designs can reduce the awkward postures and motions during wheelbarrow tasks, further research into the effectiveness of these interventions, including spine loading and long long-term use, is necessary.