An EMG-driven model applied for predicting metabolic energy consumption during movement.

Area of Science:

• Biomechanics
• Human Movement Science
• Exercise Physiology

Background:

• The relationship between mechanical work and metabolic energy cost during human movement remains incompletely understood.
• Forward-dynamic musculoskeletal models integrated with experimental data are valuable tools for investigating movement energetics.
• An EMG-driven approach offers a promising method for modeling muscle energy expenditure.

Purpose of the Study:

• To evaluate the applicability of a whole-body muscle energy expenditure model using an EMG-driven approach.
• To compare model predictions of metabolic energy consumption with experimentally measured values during squat exercise.
• To assess the model's accuracy across different exercise frequencies and load levels.

Main Methods:

• Four participants performed squat exercises on a unilateral leg press at varying frequencies and loads.
• Collected data included kinematics, electromyography (EMG), foot forces/moments, and gas exchange.
• A musculoskeletal model, driven by EMG and kinematics, simulated muscle forces and energetics, with maximal isometric muscle force optimized to match measured joint moments.

Main Results:

• Model predictions for metabolic energy consumption were comparable to indirect calorimetry measurements.
• The model underestimated measured energy consumption at higher movement frequencies.
• This underestimation was attributed to the energy cost of non-muscular mass increasing with movement velocity.

Conclusions:

• The EMG-driven muscle energy expenditure model demonstrated promising accuracy when compared to experimental data.
• Further research is warranted to refine and validate this modeling approach for calculating mechanical and metabolic work.
• The findings contribute to a better understanding of the interplay between mechanical work and energy expenditure in human movement.