Kinematic effects of repeated turns while running

Area of Science:

• Sports Medicine
• Biomechanics
• Exercise Physiology

Background:

• Non-contact anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries in team sports are often associated with abrupt changes in direction.
• Fatigue is a known risk factor for knee injuries due to its negative impact on dynamic neuromuscular control.

Purpose of the Study:

• To investigate the effects of repeated 180° turns during a high-intensity running protocol on lower limb joint kinematics and centre-of-mass (CoM) movement.
• To assess how fatigue influences these kinematic parameters throughout the exercise.

Main Methods:

• Twenty young men performed a 5-minute high-intensity shuttle running test (75% max aerobic speed) involving repeated 180° turns.
• Motion capture system recorded lower limb joint and CoM kinematics.
• Kinematic data were compared between the first and last minute of exercise.

Main Results:

• Significant reductions in hip flexion (-60%) and knee flexion (-40%) were observed.
• Increased hip adduction and internal rotation (+25-30%) occurred.
• These changes indicate altered movement patterns potentially increasing knee injury risk.

Conclusions:

• Prolonged, repeated 180° turns under fatigue conditions can lead to biomechanical changes that elevate the risk of non-contact knee ligament injuries.
• Neuromuscular training, particularly during later stages of practice, is recommended for injury prevention in team sports.