Gender differences in the viscoelastic properties of tendon structures

Area of Science:

• Biomechanics
• Human Physiology
• Musculoskeletal System

Background:

• Tendon and aponeurosis viscoelastic properties are crucial for muscle function and performance.
• Previous research suggests potential sex-based differences in musculoskeletal mechanics, but specific tendon properties remain under-investigated.

Purpose of the Study:

• To investigate and compare the viscoelastic properties of the medial gastrocnemius tendon and aponeurosis between men and women.
• To determine if sex influences tendon strain, stiffness, Young's modulus, and hysteresis during isometric plantar flexion.

Main Methods:

• Ultrasonography was used to measure tendon and aponeurosis elongation in 16 men and 13 women during ramp isometric plantar flexion to maximum voluntary contraction.
• Muscle force and tendon elongation data were analyzed to calculate stiffness, Young's modulus, and hysteresis (energy dissipation).

Main Results:

• Women showed significantly greater tendon elongation and maximum strain compared to men.
• Women exhibited significantly lower stiffness and Young's modulus in their tendon structures.
• Hysteresis was significantly lower in women compared to men, indicating less energy dissipation.

Conclusions:

• Significant sex-based differences exist in the viscoelastic properties of the medial gastrocnemius tendon and aponeurosis.
• These differences, particularly lower stiffness and hysteresis in women, may contribute to observed performance disparities between sexes.
• Findings highlight the importance of considering sex-specific biomechanical characteristics in athletic performance and injury research.