[Study on perceived fatigue evaluating model during simulated load carriage].

Area of Science:

• Biomechanics
• Human Factors Engineering
• Ergonomics

Background:

• Load carriage research often relies on subjective fatigue measures.
• Objective variables are needed for a more reliable fatigue evaluation model.
• Simulated load carriage experiments provide a controlled environment for data collection.

Purpose of the Study:

• To develop a perceived fatigue evaluating model for simulated load carriage using objective variables.
• To analyze the relationship between shoulder force, trunk pressure, and perceived fatigue.
• To provide an analytical technique for load carriage research.

Main Methods:

• 14 healthy males walked for 50 minutes at 5 km/h on a 0% slope with varying backpack loads (25-37 kg).
• Shoulder force and trunk pressure were measured and analyzed using time- and frequency-domain methods.
• Multivariable linear regression was employed to construct the fatigue model.

Main Results:

• A fatigue model was established using shoulder force, trunk pressure distribution ratio, load, and body mass index (BMI), achieving an adjusted R-squared of 0.709.
• The model demonstrated an absolute percentage error of less than 20% at the experiment's end.
• Frequency-domain variables yielded a better model fit than time-domain variables, and BMI inclusion improved accuracy.

Conclusions:

• The developed perceived fatigue model for load carriage is objective and does not require physiological monitoring.
• This model can be utilized in developing evaluation systems for human load carriage, potentially using dummies in experiments.
• It provides a scientific foundation for optimizing human load carriage strategies.