Relationship between Nordic hamstring strength and maximal voluntary eccentric, concentric and isometric knee flexion...

Area of Science:

• Sports Medicine
• Biomechanics
• Exercise Physiology

Background:

• The Nordic hamstring exercise is widely used for preventing hamstring injuries and assessing risk.
• The precise meaning of Nordic hamstring strength in relation to muscle function remains unclear.

Purpose of the Study:

• To investigate the relationship between Nordic hamstring strength and maximal voluntary contraction (MVC) torque of the knee flexors.
• To determine if Nordic hamstring strength is associated with isometric, concentric, or eccentric knee flexor torque measured via isokinetic dynamometry.

Main Methods:

• Sixteen healthy young men performed the Nordic hamstring exercise, with ankle joint torque measured.
• Maximal voluntary contraction (MVC) torque of knee flexors was assessed using an isokinetic dynamometer under isometric, concentric, and eccentric conditions at various angles and speeds.
• Pearson's correlation coefficients were used to analyze the relationships between Nordic hamstring torque and MVC torque.

Main Results:

• Peak Nordic hamstring torque values were recorded.
• No significant correlations were found between peak Nordic hamstring torque and peak eccentric knee flexion torque.
• No significant correlations were observed between Nordic hamstring torque and isometric or concentric MVC torque.

Conclusions:

• Nordic hamstring strength is not significantly associated with knee flexor torque measured by isokinetic dynamometry.
• Factors other than static and dynamic hamstring strength likely influence performance in the Nordic hamstring exercise.
• Further research is needed to elucidate the determinants of Nordic hamstring strength.