Crossover cutting during hamstring fatigue produces transverse plane knee control deficits

Area of Science:

• Sports Biomechanics
• Movement Science
• Exercise Physiology

Background:

• Athletic performance relies on efficient biomechanics during directional changes.
• Hamstring muscle fatigue is common in sports and can alter movement patterns.
• Understanding fatigue effects on knee and ankle dynamics is crucial for injury prevention.

Purpose of the Study:

• To investigate the impact of eccentric hamstring fatigue on knee and ankle movement during a running crossover cut.
• To analyze changes in both sagittal and transverse plane (axial) joint dynamics and kinetics.

Main Methods:

• Employed a pretest-posttest, single-group design in a biodynamics laboratory.
• Twenty female athletes underwent 3 weeks of crossover cutting training.
• Collected 3D kinematic and ground reaction force data during unfatigued and fatigued states.

Main Results:

• Increased knee internal rotation velocity during the initial phase of the cut.
• Decreased peak transverse plane knee rotation during propulsion in the fatigued state.
• Earlier onset of peak ankle plantar flexor moments, showing a relationship with knee rotation and hamstring torque.

Conclusions:

• Hamstring fatigue leads to deficits in dynamic knee control, evidenced by increased internal rotation.
• The lower leg musculature, particularly ankle plantar flexors, may compensate to stabilize the knee during fatigued pivot shifts.
• Ankle plantar flexor activation appears to be a key compensatory mechanism for dynamic knee stabilization when hamstring function is compromised.