Modulating the Nordic Hamstring Exercise from 'zero to hero': a stepwise progression explored in a high-performance athlete

Key points

1. 01A 6-level stepwise progression with 20 exercise variations spans from 69% to 154% of standard Nordic hamstring exercise peak moment
2. 02Hip flexion (90 degrees) had large effects on all variables (effect size 2.80 to 6.66), reducing muscle activity by 63% for biceps femoris long head and 55% for semitendinosus
3. 03Shank inclination (30 degrees) and additional load (5 kg) produced only small to moderate effects (effect size 0.24 to 0.72)
4. 04Three exercise variations favored greater biceps femoris long head activation, which is key for hamstring injury prevention
5. 05Five standardized cutoff exercises allow classification into performance levels without measurement equipment

How it was conducted

Design

Exploratory single-subject case study

Participant

One male long-jumper, age 33, height 171 cm, mass 69 kg, 6 years of Nordic hamstring exercise experience

Variations tested

20 facilitating and intensifying Nordic hamstring exercise variations across 3 test sessions (72 hours apart)

Measurements

Kinematics, kinetics via isokinetic dynamometer (200 Hz), and surface EMG of biceps femoris long head and semitendinosus (2000 Hz)

Muscle activity normalization

Normalized to maximal voluntary isometric contraction (MVIC) in the Nordic hamstring plank activation pose

Statistical approach

Cohen d effect sizes with 90% CIs; small <0.5, moderate 0.5-0.8, large >0.8

What they found

• Peak moments ranged from 69% (zigzag pose) to 154% (inclined bent single-legged version) versus the standard Nordic hamstring exercise
• Peak biceps femoris long head activity ranged from 15.3% to 128.3% MVIC across all variations
• Peak semitendinosus activity ranged from 25.7% to 132.4% MVIC across all variations
• Hip flexion (90 degrees) elicited large effects on all variables (d = 2.80 to 6.66), reducing peak hamstring activity by 63% MVIC for biceps femoris long head and 55% MVIC for semitendinosus
• Shank inclination (30 degrees) and additional load (5 kg) produced small to moderate effects (d = 0.24 to 0.72) on peak moments and muscle activity
• 10 of 20 variations showed similar biceps femoris long head and semitendinosus activations (less than 10% difference); 3 favored biceps femoris long head, 7 favored semitendinosus
• The highest biceps femoris long head activation (128.3% +/- 8.0% MVIC) occurred during guided final-stage activation (level 1C)
• Mean knee extension velocity during the standard version was 11.1 +/- 0.6 degrees/s across a ROM of 81.6 +/- 1.1 degrees

Limitations

• Single-participant case study limits generalizability; findings must be replicated in heterogeneous groups of varying age, sex, and training background
• All variations were performed under controlled, isokinetic conditions that may not reflect real-world training settings
• Only one highly experienced, uninjured athlete was tested, so the model has not been validated in beginners, injured individuals, or clinical populations
• Supramaximal execution (with natural downward acceleration) was not analyzed due to fatigue concerns, so the full potential of some variations remains untested

Why it matters

For patients

Patients recovering from hamstring injury or with limited strength may be able to use the easier levels of this progression to safely load the hamstring without overexertion.

For clinicians

The 6-level model and 5 cutoff exercises give practitioners a structured, equipment-minimal framework to individually progress Nordic hamstring exercise loading, with hip flexion being the most powerful modifier to reduce difficulty.

For readers

This case study maps how changing hip angle, shank inclination, and added load alters Nordic hamstring exercise demand, providing a logical rationale for personalizing one of the most evidence-backed hamstring injury prevention exercises.