Eccentric force and electromyogram comparison between the eccentric phase of the Nordic hamstring exercise and the...

Area of Science:

• Biomechanics and Exercise Physiology
• Muscle Activation and Strength Training

Background:

• The Nordic hamstring exercise (NHE) and razor hamstring curl (RHC) are common for developing hamstring eccentric strength.
• Optimal exercise selection for hamstring training and rehabilitation requires understanding the differences in muscle loading and intensity between NHE and RHC.

Purpose of the Study:

• To compare the peak eccentric force and muscle surface electromyogram (s-EMG) activity during NHE and RHC.
• To provide data to inform the prescription of NHE or RHC for training and rehabilitation.

Main Methods:

• Fifteen healthy male university students performed maximal voluntary isometric contractions, followed by NHE and RHC in a randomized order.
• Peak eccentric force and s-EMG amplitude of the medial gastrocnemius, lateral gastrocnemius, biceps femoris, semitendinosus, gluteus maximus, and erector spinae were measured.

Main Results:

• Peak eccentric force was significantly higher during RHC compared to NHE (p = 0.001).
• Surface electromyogram (s-EMG) activity of the semitendinosus was significantly higher during NHE compared to RHC (p = 0.04).
• No significant differences in s-EMG activity were found for the medial gastrocnemius, lateral gastrocnemius, biceps femoris, gluteus maximus, or erector spinae between the two exercises.

Conclusions:

• RHC elicits a greater peak eccentric force than NHE.
• NHE demonstrates higher semitendinosus muscle activation compared to RHC.