Acute Static Stretching Results in Muscle-Specific Alterations amongst the Hamstring Muscles

Area of Science:

• Sports Medicine
• Biomechanics
• Exercise Physiology

Background:

• Static stretching is commonly used to improve flexibility.
• Its acute effects on hamstring musculotendinous properties and muscle-specific responses remain incompletely understood.

Purpose of the Study:

• To investigate the acute effects of static stretching on the musculotendinous properties of the semitendinosus and biceps femoris muscles.
• To compare the muscle-specific responses of these two hamstring muscles to static stretching.

Main Methods:

• Twelve male volunteers participated in two testing sessions.
• Measurements included myotendinous junction (MTJ) displacement, passive torque, and maximal voluntary isometric torque (MVIT) before and after static stretching.
• Static stretching involved five sets of 30-second holds.

Main Results:

• Static stretching significantly decreased maximal voluntary isometric torque (MVIT) and passive torque.
• The semitendinosus muscle exhibited greater MTJ displacement than the biceps femoris muscle before stretching.
• The biceps femoris muscle showed a greater relative change in MTJ displacement after stretching compared to the semitendinosus muscle.

Conclusions:

• Hamstring muscles exhibit specific acute responses to static stretching.
• While stretching impairs torque production, the observed changes in passive torque and MTJ displacement may have implications for hamstring injury prevention.