Functional differences in the activity of the hamstring muscles with increasing running speed

Area of Science:

• Biomechanics
• Exercise Physiology
• Sports Science

Background:

• Understanding hamstring muscle function is crucial for athletic performance and injury prevention.
• Previous research has focused on overall hamstring activation, with less detail on individual muscle contributions at varying speeds.

Purpose of the Study:

• To investigate the distinct activation patterns of the biceps femoris and semitendinosus muscles across a range of running speeds.
• To elucidate the functional characteristics of individual hamstring muscles during dynamic locomotion.

Main Methods:

• Eight healthy male track and field athletes ran on a treadmill at 50%, 75%, 85%, and 95% of their maximum velocity.
• Lower extremity kinematics (hip and knee joints) were measured.
• Surface electromyography (EMG) recorded the activity of the biceps femoris and semitendinosus muscles.

Main Results:

• Hamstring muscle activation significantly increased during the late swing phase at 95% maximum velocity.
• The semitendinosus showed greater activity than the biceps femoris during the middle swing phase at 75%, 85%, and 95% speeds.
• Distinct differences in peak activation timing between the biceps femoris and semitendinosus were observed at 95% maximum velocity.

Conclusions:

• Running speed significantly influences the activation patterns of individual hamstring muscles.
• Complex neuromuscular coordination between the biceps femoris and semitendinosus is evident at near-maximum sprinting speeds.
• These findings enhance our understanding of hamstring muscle function during high-intensity running.