Personalized Muscle Strength Improves Accuracy of Military Load Carriage Simulations

Area of Science:

• Biomechanics
• Musculoskeletal modeling
• Military medicine

Background:

• Military overuse injuries are linked to load carriage and poor physical fitness.
• Muscle strength is a modifiable factor crucial for injury prevention.
• Generic musculoskeletal models lack accuracy for military populations due to strength differences.

Purpose of the Study:

• To assess how personalizing muscle strength in musculoskeletal models affects prediction accuracy.
• To evaluate the impact of strength-scaled models on muscle excitation predictions during simulated military load carriage.

Main Methods:

• Measured maximum voluntary isometric contractions of key muscle groups in 16 active-duty military personnel.
• Created strength-scaled musculoskeletal models using personalized maximum isometric force data.
• Compared muscle excitation predictions from generic and strength-scaled models during walking with and without a 46 kg load using electromyography data.

Main Results:

• Personalized muscle strength scaling significantly improved muscle excitation prediction accuracy (p<0.001).
• Strength-scaled models provided more accurate simulations for military personnel carrying heavy loads.
• Enhanced model accuracy facilitates better prediction of internal joint mechanics.

Conclusions:

• Personalizing musculoskeletal models with individual muscle strength is vital for accurate simulations in military contexts.
• Improved musculoskeletal models can enhance the understanding of injury mechanisms and the evaluation of prevention strategies.
• This approach supports the development of targeted interventions for military overuse injuries.