The Effects of Ramp Gradients and Pushing-Pulling Techniques on Lumbar Spinal Load in Healthy Workers
Chalearmpong Pinupong1,2, Wattana Jalayondeja1,3, Keerin Mekhora1
1Faculty of Physical Therapy, Mahidol University, Thailand.
Safety and Health at Work
|September 30, 2020
Summary
Moving carts on ramps increases lumbar spinal load. Pushing carts, especially on inclines, is recommended over pulling to reduce compression and shear forces, thereby lowering the risk of low back pain.
Area of Science:
- Occupational biomechanics
- Ergonomics
- Industrial safety
Background:
- Many industrial and healthcare jobs involve moving carts on ramps, posing risks for low back pain.
- Optimizing cart-moving techniques is crucial for reducing occupational injuries.
Purpose of the Study:
- To investigate the impact of handling techniques and ramp slope on lumbar spinal loads.
- To compare the biomechanical effects of pushing versus pulling carts on inclines.
Main Methods:
- A 2x2x4 factorial design was employed, examining two handling techniques (pushing/pulling) and four ramp slopes (0-20 degrees).
- 3D motion capture and subject anthropometrics were used to calculate lumbar spinal loads via the 3DSSPP program for 30 healthy male workers.
Main Results:
- Handling technique, direction, and slope significantly affected lumbar spine compression and shear forces (p < 0.001).
- Increasing ramp gradient amplified L4/5 compression forces for both pushing and pulling.
- Pulling generated higher compression and shear forces than pushing at steeper slopes.
Conclusions:
- Appropriate cart-moving techniques can significantly mitigate high spinal loads.
- Pushing carts is recommended over pulling when moving them up or down ramps to minimize injury risk.
