Low-back biomechanics and static stability during isometric pushing

Area of Science:

• Occupational Biomechanics
• Ergonomics
• Industrial Safety

Background:

• Pushing and pulling tasks are common in industrial settings.
• Limited research exists on low-back biomechanical risk factors for pushing.
• Spinal stability during pushing exertions has not been quantified.

Purpose of the Study:

• To investigate biomechanical risk factors associated with pushing.
• To quantify spinal stability during isometric pushing exertions.
• To analyze the influence of exertion level, handle elevation, and foot position on pushing biomechanics.

Main Methods:

• Collected data from 11 healthy participants performing isometric pushing exertions.
• Utilized a biomechanical model to analyze posture and hand force data.
• Quantified trunk posture, force vector direction, and trunk moment.

Main Results:

• Trunk posture, force direction, and trunk moment were significantly influenced by exertion level, handle elevation, and foot position (p < .01).
• Pushing exertions showed significantly less stability than lifting when muscle cocontraction was ignored (p < .01).
• Stability during pushing can be enhanced by muscle cocontraction, which increases spinal load and potential injury risk.

Conclusions:

• Pushing exertions inherently provide less intrinsic trunk stability compared to lifting.
• Muscle cocontraction is likely employed to compensate for low intrinsic stability during pushing.
• Considering muscle cocontraction is crucial for accurate biomechanical risk assessment in industrial pushing tasks to prevent overload injuries.