Quantification of Cervical Musculature Using Magnetic Resonance Imaging in Military Pilots

Area of Science:

• Biomechanics
• Musculoskeletal modeling
• Human anatomy

Background:

• Cervical spine musculature is vital for head-neck stability and load-bearing.
• Accurate muscle morphology in computational models is essential for estimating spinal loads and load sharing.
• Current models lack cervical muscle data specific to fighter pilot populations.

Purpose of the Study:

• To obtain and describe cervical muscle morphological data from U.S. Air Force pilots.
• To provide data for enhancing musculoskeletal injury models for fighter pilots.
• To inform the development of more accurate computational models of the pilot neck.

Main Methods:

• Nine experienced pilots underwent supine magnetic resonance imaging (MRI).
• Cross-sectional areas of key flexor and extensor cervical muscles were measured.
• Muscle segmentation was performed on axial MRI views at each spinal segment's inferior vertebral endplate.

Main Results:

• Pilot demographics: 2 female, 7 male; mean age 39±5 years; BMI 27±2 kg/m².
• Flexor muscles: Sternocleidomastoid area decreased cranially; longus capitis area peaked at C3.
• Extensor muscles: Semispinalis capitis area increased superiorly; others showed no consistent pattern.

Conclusions:

• Cervical muscle cross-sectional areas vary by muscle type, action, and spinal level in pilots.
• These unique patterns are linked to factors like head-supported mass, cockpit ergonomics, and high-g forces.
• Data can refine musculoskeletal models for predicting neck loads and load sharing in military scenarios.