Effects of the optimal flexor/extensor ratio on G-tolerance

Area of Science:

• Aerospace Medicine
• Human Physiology
• Sports Science

Background:

• Understanding the physiological demands of high G-force exposure is critical for military aviators.
• Previous research has not fully elucidated the specific muscular strength and ratio requirements for G-tolerance.

Purpose of the Study:

• To investigate the knee joint flexor/extensor ratio in Korean Air Force students.
• To compare these ratios with performance in a G-tolerance test.
• To identify key muscular factors influencing G-tolerance.

Main Methods:

• Body composition analysis using impedance method in 77 Korean Air Force students.
• Isokinetic muscular function testing (Humac Norm) at 60°/sec and 240°/sec.
• Comparison of muscular function data between students who passed and failed G-tolerance tests.

Main Results:

• Higher muscle mass and fat percentages were observed in students who passed or failed C compared to failed A.
• Passing students showed higher left knee flexion peak torque and total extension work than failed groups.
• Both passing and failed C groups exhibited superior trunk flexor/extensor ratios compared to failed A.

Conclusions:

• A balanced knee flexor/extensor ratio and a high trunk flexor/extensor ratio are essential for high G-tolerance.
• Enhanced maximum muscular strength is necessary for adapting to rapid acceleration phases.
• These findings can inform training programs for aviators to improve G-force resilience.