Traditional and Band-Assisted Nordic Hamstring Training Improves Knee Flexor Strength and Hip Range of Motion

Abstract

Purpose

To compare the training effects of traditional (TRAD) and band-assisted (NHE_ASSIST) Nordic Hamstring Exercise on knee flexor force-length characteristics, NHE execution, and hip range of motion (ROM).

Methods

Forty-five male (n = 24) and female (n = 21) collegiate athletes were recruited from a variety of sports (soccer, basketball, Gaelic football, rugby, athletics, and netball) to partake in a twice-weekly 8-week TRAD or NHE_ASSIST training programme; 30 participants completed the intervention with ≥ 80% adherence. Knee flexor force production capacity (eccentric and isometric [at various lengths]), NHE execution, and hip ROM were examined pre- and post-training. Soreness was self-reported up to 48 h post-training using a visual analogue scale.

Results

No significant (P > 0.05) group × time interaction effects nor main effects of group were revealed for any metric. Main effects of time revealed significant increases in eccentric (17% ± 19%) and isometric force at longer muscle lengths (180° [full extension] and 150° knee flexion; 9%–12% ± 20%–22%), break point angle (10 ± 11°), impulse (139% ± 159%), and hip flexion ROM (5 ± 6°) in both groups after training; larger effect sizes occurred within NHE_ASSIST compared to TRAD regarding force production capacity, break point angle, impulse, and hip flexion ROM.

Conclusion

Eight weeks of NHE improved knee flexor strength (particularly at longer muscle lengths), NHE execution, and hip flexion ROM. NHE_ASSIST did not confer statistically different adaptations than TRAD; however, early-phase soreness was transiently lower within NHE_ASSIST. Larger, standardised, and mechanistically informed trials are warranted to determine whether assistance meaningfully augments adaptations.

Keywords

Sports medicine / Resistance training / Eccentric training / Injury prevention / Force-length

References

[1] Gimigliano F, Resmini G, Moretti A, Aulicino M, Gargiulo F, Gimigliano A, et al.. Epidemiology of Musculoskeletal Injuries in Adult Athletes: A Scoping review. Med (B Aires), 2021, 57: 1118

[2] Maniar N, Carmichael D, Hickey J, Timmins R, San Jose A, Dickson J, et al.. Incidence and prevalence of hamstring injuries in field-based team sports: a systematic review and meta-analysis of 5952 injuries from over 7 million exposure hours. Br J Sports Med, 2023, 57: 109-16

[3] Koulouris G, Connell D, Brukner P, Schneider-Kolsky M. Magnetic Resonance Imaging Parameters for Assessing Risk of Recurrent Hamstring Injuries in Elite Athletes. Am J Sports Med, 2007, 35: 1500-6

[4] Dolman B, Verrall G, Reid I. Physical principles demonstrate that the biceps femoris muscle relative to the other hamstring muscles exerts the most force: implications for hamstring muscle strain injuries. Muscles Ligaments Tendons J, 2014, 4(3): 371-7

[5] Thelen D, Chumanov E, Hoerth D, Best T, Swanson S, Li L, et al.. Hamstring Muscle Kinematics during Treadmill Sprinting. Med Sci Sports Exerc, 2005, 37(1): 108-14

[6] Kenneally-Dabrowski C, Brown N, Lai A, Perriman D, Spratford W, Serpell B. Late swing or early stance? A narrative review of hamstring injury mechanisms during high‐speed running. Scand J Med Sci Sports, 2019, 29(8): 1083-91

[7] Andrews M, Shield A, Lichtwark G, Pincheira P. Hamstring Injury Mechanisms and Eccentric Training-Induced Muscle Adaptations: Current Insights and Future Directions. Sports Med, 2025, 55(10): 2429-43

[8] Opar D, Williams M, Timmins R, Hickey J, Duhig S, Shield A. Eccentric Hamstring Strength and Hamstring Injury Risk in Australian Footballers. Med Sci Sports Exerc, 2015, 47(4): 857-65

[9] Timmins R, Shield A, Williams M, Lorenzen C, Opar D. Architectural adaptations of muscle to training and injury: a narrative review outlining the contributions by fascicle length, pennation angle and muscle thickness. Br J Sports Med, 2016, 50: 1467-72

[10] Bourne M, Opar D, Williams M, Shield A. Eccentric Knee Flexor Strength and Risk of Hamstring Injuries in Rugby Union. Am J Sports Med, 2015, 43: 2663-70

[11] Brockett C, Morgan D, Proske U. Predicting Hamstring Strain Injury in Elite Athletes. Med Sci Sports Exerc, 2004, 36(3): 379-87

[12] Medeiros D, Marchiori C, Baroni B. Effect of Nordic Hamstring Exercise Training on Knee Flexors Eccentric Strength and Fascicle Length: A Systematic Review and Meta-Analysis. J Sport Rehabil, 2021, 30: 482-91

[13] van Dyk N, Behan F, Whiteley R. Including the Nordic hamstring exercise in injury prevention programmes halves the rate of hamstring injuries: a systematic review and meta-analysis of 8459 athletes. Br J Sports Med, 2019, 53(21): 1362-70

[14] Van Hooren B, Vanwanseele B, van Rossom S, Teratsias P, Willems P, Drost M, et al.. Muscle forces and fascicle behavior during three hamstring exercises. Scand J Med Sci Sports, 2022, 32(6): 997-1012

[15] Raiteri B, Beller R, Hahn D. Biceps femoris long head muscle fascicles actively lengthen during the Nordic hamstring exercise. Front Sports Act Living, 2021, 3 ArticleID: 669813

[16] Couppé C, Svensson R, Silbernagel K, Langberg H, Magnusson S. Eccentric or Concentric Exercises for the Treatment of Tendinopathies?. J Orthop Sports Phys Therapy, 2015, 45(11): 853-63

[17] Matthews M, Jones P, Cohen D, Matthews H. The Assisted Nordic Hamstring Curl. Strength Cond J, 2015, 37: 84-7

[18] Alt T, Knicker A, Nodler Y, Strüder H. Assisted or unassisted Nordic hamstring exercise? — Resistance exercise determinants at a glance. Sports Biomech, 2024, 23: 831-45

[19] Diong J, Carden P, O’Sullivan K, Sherrington C, Reed D. Eccentric exercise improves joint flexibility in adults: a systematic review update and meta-analysis. Musculoskelet Sci Pract, 2022, 60: 102556

[20] Kay A, Baxter B, Hill M, Blazevich A. Effects of eccentric resistance training on lower-limb passive joint range of motion: a systematic review and meta-analysis. Med Sci Sports Exerc, 2023, 55(4): 710-21

[21] Hinks A, Franchi M, Power G. The influence of longitudinal muscle fascicle growth on mechanical function. J Appl Physiol, 2022, 133(1): 87-103

[22] Ishøi L, Meincke S, Lund A, Stenholm A, DeLang M, Thornton K, et al.. Less pain, same gain? A randomized controlled trial comparing assisted- versus non-assisted Nordic hamstring exercise training in elite youth football players. Phys Ther Sport, 2025, 73: 39-47

[23] Bahr R, Thorborg K, Ekstrand J. Evidence-based hamstring injury prevention is not adopted by the majority of Champions League or Norwegian Premier League football teams: the Nordic Hamstring survey. Br J Sports Med, 2015, 49(22): 1466-71

[24] Ripley N, Cuthbert M, Ross S, Comfort P, McMahon J. The effect of exercise compliance on risk reduction for hamstring strain injury: a systematic review and meta-analyses. Int J Environ Res Public Health, 2021, 18(21): 11260

[25] Lau W, Blazevich A, Newton M, Wu S, Nosaka K. Reduced muscle lengthening during eccentric contractions as a mechanism underpinning the repeated-bout effect. Am J Physiology-Regulatory Integr Comp Physiol, 2015, 308(10): R879-86

[26] Coratella G, Cè E, D’Orlando A, Steri E, Padovan R, Spina O, et al.. Muscle damage and the repeated-bout effect after a typical nordic hamstring exercise session. Int J Sports Med, 2025, 46(10): 759-67

[27] Hyldahl R, Chen T, Nosaka K. Mechanisms and mediators of the skeletal muscle repeated bout effect. Exerc Sport Sci Rev, 2017, 45(1): 24-33

[28] Pettitt R, Symons J, Eisenman P, Taylor J, White A. Repetitive eccentric strain at long muscle length evokes the repeated bout effect. J Strength Cond Res, 2005, 19(4): 918-24

[29] Cuthbert M, Ripley N, McMahon J, Evans M, Haff G, Comfort P. The effect of nordic hamstring exercise intervention volume on eccentric strength and muscle architecture adaptations: a systematic review and meta-analyses. Sports Med, 2020, 50(1): 83-99

[30] McKay A, Stellingwerff T, Smith E, Martin D, Mujika I, Goosey-Tolfrey V, et al.. Defining training and performance caliber: a participant classification framework. Int J Sports Physiol Perform, 2022, 17(2): 317-31

[31] Gajdosik R, Rieck M, Sullivan D, Wightman S. Comparison of four clinical tests for assessing hamstring muscle length. J Orthop Sports Phys Therapy, 1993, 18(5): 614-8

[32] Opar D, Piatkowski T, Williams M, Shield A. A novel device using the nordic hamstring exercise to assess eccentric knee flexor strength: a reliability and retrospective injury study. J Orthop Sports Phys Therapy, 2013, 43(9): 636-40

[33] Sconce E, Heller B, Maden-Wilkinson T, Hamilton N. Agreement between methods and terminology used to assess the kinematics of the Nordic hamstring exercise. J Sports Sci, 2021, 39(24): 2859-68

[34] Bishop C, Read P, Lake J, Chavda S, Turner A. Interlimb asymmetries: understanding how to calculate differences from bilateral and unilateral tests. Strength Cond J, 2018, 40(4): 1-6

[35] Morag T. Editor. Exercise leadership in cardiac rehabilitation: an evidence-based approach. Hoboken, New Jersey: Wiley; 2006.

[36] Slade S, Dionne C, Underwood M, Buchbinder R. Consensus on exercise reporting template (CERT): explanation and elaboration statement. Br J Sports Med, 2016, 50(23): 1428-37

[37] Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. London: Routledge; 1988. https://doi.org/10.4324/9780203771587.

[38] Koo T, Li M. A guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med, 2016, 15(2): 155-63

[39] Lazarczuk S, Maniar N, Opar D, Duhig S, Shield A, Barrett R, et al.. Mechanical, material and morphological adaptations of healthy lower limb tendons to mechanical loading: a systematic review and meta-analysis. Sports Med, 2022, 52(10): 2405-29

[40] Valdes O, Inzulza S, Collao N, Garcia-Vicencio S, Tufano J, Earp J, et al.. Eccentric cycling is an alternative to nordic hamstring exercise to increase the neuromuscular function of knee flexors in untrained men. J Strength Cond Res, 2023, 37(11): 2158-66

[41] Delahunt E, McGroarty M, De Vito G, Ditroilo M. Nordic hamstring exercise training alters knee joint kinematics and hamstring activation patterns in young men. Eur J Appl Physiol, 2016, 116(4): 663-72

[42] Mjølsnes R, Arnason A, Østhagen T, Raastad T, Bahr R. A 10-week randomized trial comparing eccentric vs. concentric hamstring strength training in well-trained soccer players. Scand J Med Sci Sports, 2004, 14(5): 311-7

[43] Brughelli M, Cronin J. Altering the Length-Tension Relationship with Eccentric Exercise Implications for Performance and Injury. 2007;37(9):807–26. https://doi.org/10.2165/00007256-200737090-00004.

[44] Hosseini E, Alimoradi M, Iranmanesh M, Saki F, Konrad A. The effects of 8 weeks of dynamic hamstring stretching or nordic hamstring exercises on balance, range of motion, agility, and muscle performance among male soccer players with hamstring shortness: a randomized controlled trial. BMC Sports Sci Med Rehabil, 2025, 17(1): 187

[45] Freitas S, Mendes B, Le Sant G, Andrade R, Nordez A, Milanovic Z. Can chronic stretching change the muscle-tendon mechanical properties? A review. Scand J Med Sci Sports, 2018, 28(3): 794-806

[46] Franchi MV, Reeves ND, Narici MV. Skeletal muscle remodeling in response to eccentric vs. concentric loading: morphological, molecular, and metabolic adaptations. Front Physiol, 2017, 8: 447

[47] Sullivan G, Feinn R. Using effect size—or why the P value is not enough. J Grad Med Educ, 2012, 4(3): 279-82

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