Task demand and load carriage experience affect gait variability among military cadets

Area of Science:

• Biomechanics
• Human Movement Science
• Military Physiology

Background:

• Load carriage is a fundamental military task impacting soldier performance.
• Gait variability (GV) offers insights into movement control and adaptability.
• Understanding experience-related differences in gait during load carriage is vital for training and equipment design.

Purpose of the Study:

• To investigate how load carriage and military experience affect gait variability (GV).
• To determine if experience-related differences in GV are influenced by task demands (load levels).
• To assess the utility of different GV measures in distinguishing between experienced and less experienced soldiers.

Main Methods:

• Compared gait variability (spatiotemporal, joint kinematics, Lyapunov exponents) in experienced (n=30) and less experienced (n=30) military cadets.
• Participants performed load carriage tasks under three conditions: no load, 16 kg, and 32 kg.
• Analyzed differences in mean gait parameters and various GV measures between experience groups and load conditions.

Main Results:

• Gait variability measures were more sensitive to experience than mean gait parameters.
• Experienced cadets exhibited reduced spatiotemporal and joint kinematic variability, and lower ankle dynamic stability.
• Increased load significantly elevated GV and enhanced knee short-term dynamic stability in both groups.

Conclusions:

• Gait variability provides a comprehensive assessment of adaptability, stability, and control during load carriage.
• Experience influences gait strategies, leading to reduced variability in skilled soldiers.
• GV measures are valuable for identifying experience-related differences and optimizing load carriage strategies and training.