Hamstrings functional properties in athletes with high musculo-skeletal flexibility

Area of Science:

• Biomechanics
• Sports Science

Background:

• Muscle flexibility is crucial for athletic performance.
• The mechanical properties of the hamstring muscle-tendon unit (MTU) in highly flexible athletes are not fully understood.

Purpose of the Study:

• To investigate if elite rhythmic gymnasts with superior hamstring flexibility exhibit distinct passive and contractile mechanical properties compared to controls.
• To analyze the torque-angle relationships and work output during knee flexion and extension.

Main Methods:

• Assessed flexibility, passive resistance to stretch, and concentric isokinetic maximal voluntary knee flexion/extension torques in 21 elite gymnasts and 16 age-matched athletes.
• Measurements were taken during knee extension with the hip fixed at 100° flexion.
• Torque-angle properties were analyzed, and active torque was corrected for passive resistance.

Main Results:

• Gymnasts demonstrated greater hamstring flexibility and passive resistance to stretch.
• No significant differences in peak knee flexion/extension torque were observed.
• Gymnasts achieved peak knee flexion torque at more extended knee positions, indicating a different torque-angle profile.
• Corrected active torque revealed gymnasts produced more work and maintained peak torque over a larger range of motion.

Conclusions:

• Higher hamstring muscle-tendon unit (MTU) flexibility is associated with a distinct torque-angle profile.
• This profile favors greater flexion torque production at extended knee positions.
• Highly flexible athletes exhibit an enhanced functional range of motion and mechanical work output during knee flexion.