Comparison of hamstring-to-quadriceps ratio between accelerating and decelerating sections during squat exercise

Area of Science:

• Biomechanics
• Sports Medicine
• Exercise Physiology

Background:

• Anterior cruciate ligament (ACL) injuries are common in sports, often requiring rehabilitation strategies.
• Understanding muscle activation patterns during exercises like squats is crucial for injury prevention and rehabilitation.

Purpose of the Study:

• To compare the hamstring-to-quadriceps muscle activation ratio during the accelerating and decelerating phases of the squat exercise.
• To evaluate the potential of this ratio for anterior cruciate ligament (ACL) protection.

Main Methods:

• Nine healthy males performed squat exercises.
• Muscle activity of the hamstring (medial) and quadriceps (rectus femoris) was measured.
• An accelerometer classified squat phases into accelerating and decelerating sections.

Main Results:

• The hamstring-to-quadriceps ratio was significantly higher during the decelerating phase compared to the accelerating phase.
• This suggests greater relative hamstring contribution during deceleration.

Conclusions:

• Implementing a squat strategy emphasizing the decelerating phase may enhance anterior cruciate ligament (ACL) protection.
• This approach could be beneficial for individuals with compromised ACLs, particularly after sports-related injuries.