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Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
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Concurrent changes in eccentric hamstring strength and knee joint kinematics induced by soccer-specific fatigue
1Sports Injuries Research Group, Edge Hill University, St Helens Road, Ormskirk, Lancs, L39 4QP, UK.
Summary
Soccer fatigue impairs hamstring strength and increases knee varus, heightening injury risk in male players. This contrasts with female athletes’ ACL injury risk factors.
Area of Science:
- Sports Medicine
- Biomechanics
- Injury Prevention
Background:
- Soccer players face increased injury risk late in matches due to fatigue.
- Knee joint and hamstring injuries are prevalent in soccer.
Purpose of the Study:
- To examine how soccer-specific fatigue affects knee kinematics and hamstring strength.
- To understand the biomechanical changes contributing to soccer injuries.
Main Methods:
- Ten male professional soccer players participated in laboratory-based repeated measures trials.
- Hop tasks assessed knee joint kinematics, and eccentric knee flexion measured hamstring strength at 15-minute intervals during a fatigue protocol.
Main Results:
- Knee varus at touchdown increased by approximately 4° in the final 15 minutes of the protocol (P≤0.05).
- Peak eccentric hamstring strength significantly decreased throughout the second half (P=0.045).
Conclusions:
- Reduced hamstring strength and increased knee varus during fatigue create an injury-prone state in male soccer players.
- This knee varus differs from the valgus alignment associated with ACL injury risk in female players.
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