Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI

Area of Science:

• Sports Medicine
• Biomechanics
• Rehabilitation

Background:

• Hamstring injuries are common in professional athletes.
• Understanding muscle activation patterns is crucial for injury prevention strategies.
• Previous research has not comprehensively compared various exercises for hamstring activation.

Purpose of the Study:

• To compare the effectiveness of four different exercises in activating hamstring and synergistic muscles.
• To identify which exercises provide the most substantial muscle engagement for injury prevention.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to assess muscle activation.
• Thirty-six professional soccer players were randomized into four exercise groups.
• T2-weighted MRIs measured pre- and post-exercise muscle contrast shifts.

Main Results:

• Flywheel leg curl demonstrated the highest activation in gracilis (GR), semitendinosus (ST), biceps femoris short head (BFSh), and biceps femoris long head (BFLh).
• Nordic hamstring exercise showed significant activation in GR, ST, and BFSh.
• Russian belt and conic-pulley exercises yielded minimal activation in ST and BFLh, with Russian belt also activating semimembranosus (SM).

Conclusions:

• Flywheel leg curl provides the most comprehensive hamstring and GR muscle activation among the tested exercises.
• No single exercise fully activates all hamstring and synergist muscles.
• A multimodal exercise approach is necessary to ensure complete activation of knee flexors and hip extensors for optimal hamstring injury prevention.