Skip to main content
Log in

The significant effect of the medial hamstrings on dynamic knee stability

  • KNEE
  • Published:
Knee Surgery, Sports Traumatology, Arthroscopy Aims and scope



While hamstring autograft is a popular option for the general population, BTB autograft is still significantly more popular among professional athletes due to concerns of altering knee kinematics with hamstring harvest. This study seeks to quantify the contribution of the medial hamstrings to knee stability.


Valgus knee laxity, anterior tibial translation, and rotational motion were measured in eight fresh-frozen cadaveric knees after forces were applied on the tibia in each plane (coronal, sagittal, and axial). Four muscle loading conditions were tested: (1) physiologic fully loaded pes anserinus, (2) semitendinosus only loaded, (3) gracilis only loaded, and (4) unloaded pes anserinus. The protocol was then repeated with the ACL transected.


In the ACL intact knee, the neutral position of the tibia with an unloaded pes anserinus was significantly more externally rotated (p < 0.01) and anteriorly translated (p < 0.05) at all knee flexion angles than a tibia with a physiologic loaded pes anserinus. Applying an external rotation torque significantly increased external rotation for the fully unloaded (p < 0.001), gracilis only loaded (p < 0.001), and semitendinosus only loaded (p < 0.01) conditions at all flexion angles. Applying a valgus torque resulted in a significant increase in laxity for the fully unloaded condition only at 30° of flexion (p < 0.05). Applying an anterior tibial force resulted in significant increase in anterior translation for the fully unloaded condition at all flexion angles (p < 0.01), and for the gracilis only loaded condition in 30° and 60° of flexion (p < 0.05). Similar results were seen in the ACL deficient model.


The medial hamstrings are involved in rotational, translational, and varus/valgus control of the knee. Applying anterior, external rotation, and valgus forces on the hamstring deficient knee significantly increases motion in those planes. Harvesting the gracilis and semitendinosus tendons alters native knee kinematics and stability. This is clinically relevant and should be a consideration when choosing graft source for ACL reconstruction, especially in the elite athlete population.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others


  1. Almekinders LC, Pandarinath R, Rahusen FT (2004) Knee stability following anterior cruciate ligament rupture and surgery. The contribution of irreducible tibial subluxation. J Bone Joint Surg Am 86-A(5):983–987

    Article  Google Scholar 

  2. Andriacchi TP, Mundermann A, Smith RL, Alexander EJ, Dyrby CO, Koo S (2004) A framework for the in vivo pathomechanics of osteoarthritis at the knee. Ann Biomed Eng 32(3):447–457

    Article  PubMed  Google Scholar 

  3. Armour T, Forwell L, Litchfield R, Kirkley A, Amendola N, Fowler PJ (2004) Isokinetic evaluation of internal/external tibial rotation strength after the use of hamstring tendons for anterior cruciate ligament reconstruction. Am J Sports Med 32(7):1639–1643

    Article  PubMed  Google Scholar 

  4. Arnason SM, Birnir B, Gudmundsson TE, Gudnason G, Briem K (2014) Medial hamstring muscle activation patterns are affected 1–6 years after ACL reconstruction using hamstring autograft. Knee Surg Sports Traumatol Arthrosc 22(5):1024–1029

    Article  PubMed  Google Scholar 

  5. Beynnon BD, Fleming BC, Johnson RJ, Nichols CE, Renstrom PA, Pope MH (1995) Anterior cruciate ligament strain behavior during rehabilitation exercises in vivo. Am J Sports Med 23(1):24–34

    Article  CAS  PubMed  Google Scholar 

  6. Briem K, Ragnarsdottir AM, Arnason SI, Sveinsson T (2016) Altered medial versus lateral hamstring muscle activity during hop testing in female athletes 1–6 years after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 24(1):12–17

    Article  CAS  PubMed  Google Scholar 

  7. Daniel DM, Malcom LL, Losse G, Stone ML, Sachs R, Burks R (1985) Instrumented measurement of anterior laxity of the knee. J Bone Joint Surg Am 67(5):720–726

    Article  CAS  PubMed  Google Scholar 

  8. Duquin TR, Wind WM, Fineberg MS, Smolinski RJ, Buyea CM (2009) Current trends in anterior cruciate ligament reconstruction. J Knee Surg 22(1):7–12

    Article  PubMed  Google Scholar 

  9. Elias AR, Hammill CD, Mizner RL (2015) Changes in quadriceps and hamstring cocontraction following landing instruction in patients with anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 45(4):273–280

    Article  PubMed  Google Scholar 

  10. Erickson BJ, Harris JD, Fillingham YA, Frank RM, Bush-Joseph CA, Bach BR Jr, Cole BJ, Verma NN (2014) Anterior cruciate ligament reconstruction practice patterns by NFL and NCAA football team physicians. Arthroscopy 30(6):731–738

    Article  PubMed  Google Scholar 

  11. Forster MC, Forster IW (2005) Patellar tendon or four-strand hamstring? A systematic review of autografts for anterior cruciate ligament reconstruction. Knee 12(3):225–230

    Article  PubMed  Google Scholar 

  12. Hall M, Stevermer CA, Gillette JC (2015) Muscle activity amplitudes and co-contraction during stair ambulation following anterior cruciate ligament reconstruction. J Electromyogr Kinesiol 25(2):298–304

    Article  PubMed  Google Scholar 

  13. Koutras G, Bernard M, Terzidis IP, Papadopoulos P, Georgoulis A, Pappas E (2016) Comparison of knee flexion isokinetic deficits between seated and prone positions after ACL reconstruction with hamstrings graft: Implications for rehabilitation and return to sports decisions. J Sci Med Sport 19(7):559–562

    Article  PubMed  Google Scholar 

  14. Kvist J, Kartus J, Karlsson J, Forssblad M (2014) Results from the Swedish national anterior cruciate ligament register. Arthroscopy 30(7):803–810

    Article  PubMed  Google Scholar 

  15. Li G, Rudy TW, Sakane M, Kanamori A, Ma CB, Woo SL (1999) The importance of quadriceps and hamstring muscle loading on knee kinematics and in-situ forces in the ACL. J Biomech 32(4):395–400

    Article  CAS  PubMed  Google Scholar 

  16. Lin HC, Lai WH, Shih YF, Chang CM, Lo CY, Hsu HC (2009) Physiological anterior laxity in healthy young females: the effect of knee hyperextension and dominance. Knee Surg Sports Traumatol Arthrosc 17(9):1083–1088

    Article  PubMed  Google Scholar 

  17. Lindstrom M, Strandberg S, Wredmark T, Fellander-Tsai L, Henriksson M (2013) Functional and muscle morphometric effects of ACL reconstruction. A prospective CT study with 1 year follow-up. Scand J Med Sci Sports 23(4):431–442

    Article  CAS  PubMed  Google Scholar 

  18. MacWilliams BA, Wilson DR, DesJardins JD, Romero J, Chao EY (1999) Hamstrings cocontraction reduces internal rotation, anterior translation, and anterior cruciate ligament load in weight-bearing flexion. J Orthop Res 17(6):817–822

    Article  CAS  PubMed  Google Scholar 

  19. Magnussen RA, Granan LP et al (2010) Cross-cultural comparison of patients undergoing ACL reconstruction in the United States and Norway. Knee Surg Sports Traumatol Arthrosc 18(1):98–105

    Article  PubMed  PubMed Central  Google Scholar 

  20. Mall NA, Abrams GD, Azar FM, Traina SM, Allen AA, Parker R, Cole BJ (2014) Trends in primary and revision anterior cruciate ligament reconstruction among National Basketball Association team physicians. Am J Orthop (Belle Mead NJ) 43(6):267–271

    Google Scholar 

  21. Markolf KL, Graff-Radford A, Amstutz HC (1978) In vivo knee stability. A quantitative assessment using an instrumented clinical testing apparatus. J Bone Joint Surg Am 60(5):664–674

    Article  CAS  PubMed  Google Scholar 

  22. Markolf KL, O’Neill G, Jackson SR, McAllister DR (2004) Effects of applied quadriceps and hamstrings muscle loads on forces in the anterior and posterior cruciate ligaments. Am J Sports Med 32(5):1144–1149

    Article  PubMed  Google Scholar 

  23. Mohtadi NG, Chan DS, Dainty KN, Whelan DB (2011) Patellar tendon versus hamstring tendon autograft for anterior cruciate ligament rupture in adults. Cochrane Database Syst Rev 9:CD005960

    Google Scholar 

  24. Ortiz A, Capo-Lugo CE, Venegas-Rios HL (2014) Biomechanical deficiencies in women with semitendinosus-gracilis anterior cruciate ligament reconstruction during drop jumps. PM R 6(12):1097–1106

    Article  PubMed  PubMed Central  Google Scholar 

  25. Shaieb MD, Kan DM, Chang SK, Marumoto JM, Richardson AB (2002) A prospective randomized comparison of patellar tendon versus semitendinosus and gracilis tendon autografts for anterior cruciate ligament reconstruction. Am J Sports Med 30(2):214–220

    Article  PubMed  Google Scholar 

  26. Sharma A, Flanigan DC, Randall K, Magnussen RA (2016) Does gracilis preservation matter in anterior cruciate ligament reconstruction? Syst Rev Arthrosc 32(6):1165–1173

    Article  Google Scholar 

  27. Spindler KP, Kuhn JE, Freedman KB, Matthews CE, Dittus RS, Harrell FE Jr (2004) Anterior cruciate ligament reconstruction autograft choice: bone-tendon-bone versus hamstring: does it really matter? A systematic review. Am J Sports Med 32(8):1986–1995

    Article  PubMed  Google Scholar 

  28. Struewer J, Ziring E, Oberkircher L, Schuttler KF, Efe T (2013) Isolated anterior cruciate ligament reconstruction in patients aged fifty years: comparison of hamstring graft versus bone-patellar tendon-bone graft. Int Orthop 37(5):809–817

    Article  PubMed  PubMed Central  Google Scholar 

  29. Webster KE, Feller JA, Hartnett N, Leigh WB, Richmond AK (2016) Comparison of patellar tendon and hamstring tendon anterior cruciate ligament reconstruction: a 15-year follow-up of a randomized controlled trial. Am J Sports Med 44(1):83–90

    Article  PubMed  Google Scholar 

  30. Wickiewicz TL, Roy RR, Powell PL, Edgerton VR (1983) Muscle architecture of the human lower limb. Clin Orthop Relat Res 179:275–283

    Article  Google Scholar 

  31. Williams GN, Snyder-Mackler L, Barrance PJ, Axe MJ, Buchanan TS (2004) Muscle and tendon morphology after reconstruction of the anterior cruciate ligament with autologous semitendinosus-gracilis graft. J Bone Joint Surg Am 86-A(9):1936–1946

    Article  Google Scholar 

  32. Xie X, Liu X, Chen Z, Yu Y, Peng S, Li Q (2015) A meta-analysis of bone-patellar tendon-bone autograft versus four-strand hamstring tendon autograft for anterior cruciate ligament reconstruction. Knee 22(2):100–110

    Article  PubMed  Google Scholar 

  33. Zaid M, Lansdown D, Su F, Pedoia V, Tufts L, Rizzo S, Souza RB, Li X, Ma CB (2015) Abnormal tibial position is correlated to early degenerative changes 1 year following ACL reconstruction. J Orthop Res 33(7):1079–1086

    Article  PubMed  Google Scholar 

Download references


The authors of this study have no relevant financial relationships to disclose.

Author information

Authors and Affiliations



AT conceived idea of study, carried out the cadaveric studies in the laboratory, and wrote significant portion of the manuscript. OL made substantial contributions in conception, design, and helped revise manuscript. HI was heavily involved in conducting the cadaveric studies and writing the methods portion of manuscript. MM was involved in conducting the cadaveric studies and assembling/organizing the lab setting for experimentation. MB helped with study conception, revision of manuscript, and conducting studies. TL supervised the entire cadaveric study, made substantial contribution to design, and edited final manuscript.

Corresponding author

Correspondence to Aneet S. Toor.

Ethics declarations

Conflict of interest

The authors declare that they have no competing interests.

Ethical approval

The article does not contain any studies with human participants performed by any of the authors.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Toor, A.S., Limpisvasti, O., Ihn, H.E. et al. The significant effect of the medial hamstrings on dynamic knee stability. Knee Surg Sports Traumatol Arthrosc 27, 2608–2616 (2019).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: