Is skin pressure in load carriage over-evaluated?

Area of Science:

• Biomechanics
• Human Factors Engineering
• Ergonomics

Background:

• Skin pressure measurement is crucial for assessing load carriage systems.
• Existing methods show high variability due to body contour and sensor limitations.
• Reliable pressure assessment is needed for optimizing backpack design and user comfort.

Purpose of the Study:

• To propose a simple mechanical model for predicting skin pressure under load carriage straps.
• To analyze existing literature data and experimental results for reliability assessment.
• To provide a more accurate method for evaluating interface pressure in load carriage systems.

Main Methods:

• Developed a mechanical model based on Laplace's law to predict skin pressure from strap forces.
• Analyzed existing literature data on skin pressure measurements.
• Conducted experimental testing measuring static and dynamic pressures on subjects wearing a 10 kg backpack.

Main Results:

• The proposed model accurately predicts skin pressure beneath shoulder and hip straps.
• Literature data analysis and experimental testing revealed overestimation in current interface pressure measurement methods.
• Existing methods may misguide pressure criteria for load carriage system design.

Conclusions:

• The developed mechanical model offers a reliable approach for predicting interface pressure in load carriage systems.
• Current measurement techniques often overestimate skin pressure, potentially leading to flawed design decisions.
• The model provides a valuable tool for accurate pressure prediction, aiding in the development of safer and more effective load carriage systems.