Knee Surgery, Sports Traumatology, Arthroscopy

, Volume 23, Issue 8, pp 2185–2195 | Cite as

Associations of isokinetic knee steadiness with hop performance in patients with ACL deficiency

  • Yong-Hao Pua
  • Peck-Hoon Ong
  • Jia-Ying Ho
  • Adam L. Bryant
  • Kate E Webster
  • Ross A. Clark



Contrary to the ample data available regarding the functional significance of isokinetic knee strength in patients with anterior cruciate ligament deficiency (ACLD), much less is known about the functional significance of isokinetic knee steadiness. This cross-sectional study aimed to evaluate, in patients with ACLD, the independent impact of isokinetic quadriceps and hamstrings torque steadiness on single-leg hop performance.


Eighty-seven patients with unilateral ACLD participated. Patients performed isokinetic quadriceps and hamstrings steadiness and strength testing at 60°/s on an isokinetic dynamometer. Muscle steadiness and strength were represented by the wavelet-derived mean instantaneous frequency and peak value of the torque–time curves, respectively. To measure hop performance, patients performed a single-leg hop for distance and a 6-m single-leg hop for velocity.


One of two patients [n = 45 (51 %)] had a 10 % or greater difference in knee torque frequency levels between the ACLD and contralateral knees. In multivariable models adjusted for age, sex, knee pain, and knee strength, hamstrings steadiness was significantly related with hop velocity whilst quadriceps steadiness was significantly related with both hop distance and velocity. Variance decomposition analyses suggested that quadriceps steadiness was similar in importance to hamstrings strength on hop distance and velocity.


In patients with ACLD, isokinetic knee steadiness deficits were common and were independently associated with single-leg hop performance. Knee torque steadiness—a heretofore understudied variable—may prove a useful adjunct to conventional peak torque measurements by offering additional information to researchers and rehabilitation professionals about muscle performance and neuromuscular knee control.

Level of evidence

Prognostic studies, Level III.


Force control Isokinetics Knee ACL deficiency Single-leg hop test 



This project is grant funded by Singhealth Foundation start-up grant (SHF/FG476S/2010). We thank Tan Bee Yee, the head of the Department of Physiotherapy, Singapore General Hospital, for supporting this study; John Tan Wei-Ming for his assistance; Luke Perraton for his advice; and the orthopaedic surgeons from the Singapore General Hospital for allowing us access to their patients.


  1. 1.
    Aagaard P, Simonsen EB, Andersen JL, Magnusson SP, Bojsen-Moller F, Dyhre-Poulsen P (2000) Antagonist muscle coactivation during isokinetic knee extension. Scand J Med Sci Sports 10(2):58–67PubMedCrossRefGoogle Scholar
  2. 2.
    Alkjaer T, Simonsen EB, Magnusson SP, Dyhre-Poulsen P, Aagaard P (2012) Antagonist muscle moment is increased in ACL deficient subjects during maximal dynamic knee extension. Knee 19(5):633–639PubMedCrossRefGoogle Scholar
  3. 3.
    Bandholm T, Rose MH, Slok R, Sonne-Holm S, Jensen BR (2009) Ankle torque steadiness is related to muscle activation variability and coactivation in children with cerebral palsy. Muscle Nerve 40(3):402–410PubMedCrossRefGoogle Scholar
  4. 4.
    Barber SD, Noyes FR, Mangine RE, McCloskey JW, Hartman W (1990) Quantitative assessment of functional limitations in normal and anterior cruciate ligament-deficient knees. Clin Orthop Relat Res 255:204–214PubMedGoogle Scholar
  5. 5.
    Baugher WH, Warren RF, Marshall JL, Joseph A (1984) Quadriceps atrophy in the anterior cruciate insufficient knee. Am J Sports Med 12(3):192–195PubMedCrossRefGoogle Scholar
  6. 6.
    Binkley JM, Stratford PW, Lott SA, Riddle DL (1999) The Lower Extremity Functional Scale (LEFS): scale development, measurement properties, and clinical application. Phys Ther 79(4):371–383PubMedGoogle Scholar
  7. 7.
    Brosky JA Jr, Nitz AJ, Malone TR, Caborn DN, Rayens MK (1999) Intrarater reliability of selected clinical outcome measures following anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 29(1):39–48PubMedCrossRefGoogle Scholar
  8. 8.
    Brown RE, Edwards DL, Jakobi JM (2010) Sex differences in force steadiness in three positions of the forearm. Eur J Appl Physiol 110(6):1251–1257PubMedCrossRefGoogle Scholar
  9. 9.
    Bryant AL, Clark RA, Pua YH (2011) Morphology of hamstring torque–time curves following ACL injury and reconstruction: mechanisms and implications. J Orthop Res 29(6):907–914PubMedCrossRefGoogle Scholar
  10. 10.
    Bryant AL, Creaby MW, Newton RU, Steele JR (2008) Dynamic restraint capacity of the hamstring muscles has important functional implications after anterior cruciate ligament injury and anterior cruciate ligament reconstruction. Arch Phys Med Rehabil 89(12):2324–2331PubMedCrossRefGoogle Scholar
  11. 11.
    Bryant AL, Pua YH, Clark RA (2009) Morphology of knee extension torque–time curves following anterior cruciate ligament injury and reconstruction. J Bone Joint Surg Am 91(6):1424–1431PubMedCrossRefGoogle Scholar
  12. 12.
    Burnett RA, Laidlaw DH, Enoka RM (2000) Coactivation of the antagonist muscle does not covary with steadiness in old adults. J Appl Physiol 89(1):61–71PubMedGoogle Scholar
  13. 13.
    Christou EA, Carlton LG (2001) Old adults exhibit greater motor output variability than young adults only during rapid discrete isometric contractions. J Gerontol A Biol Sci Med Sci 56(12):B524–B532PubMedCrossRefGoogle Scholar
  14. 14.
    Clark RA, Paterson K, Ritchie C, Blundell S, Bryant AL (2011) Design and validation of a portable, inexpensive and multi-beam timing light system using the Nintendo Wii hand controllers. J Sci Med Sport 14(2):177–182PubMedCrossRefGoogle Scholar
  15. 15.
    Daniel DM, Stone ML, Riehl B, Moore MR (1988) A measurement of lower limb function: the one-leg hop for distance. Am J Knee Surg 1(4):212–214Google Scholar
  16. 16.
    Danion F, Gallea C (2004) The relation between force magnitude, force steadiness, and muscle co-contraction in the thumb during precision grip. Neurosci Lett 368(2):176–180PubMedCrossRefGoogle Scholar
  17. 17.
    Enoka RM, Christou EA, Hunter SK, Kornatz KW, Semmler JG, Taylor AM, Tracy BL (2003) Mechanisms that contribute to differences in motor performance between young and old adults. J Electromyogr Kinesiol 13(1):1–12PubMedCrossRefGoogle Scholar
  18. 18.
    Fitzgerald GK, Axe MJ, Snyder-Mackler L (2000) A decision-making scheme for returning patients to high-level activity with nonoperative treatment after anterior cruciate ligament rupture. Knee Surg Sports Traumatol Arthrosc 8(2):76–82PubMedCrossRefGoogle Scholar
  19. 19.
    Frobell RB (2011) Change in cartilage thickness, posttraumatic bone marrow lesions, and joint fluid volumes after acute ACL disruption: a two-year prospective MRI study of sixty-one subjects. J Bone Joint Surg Am 93(12):1096–1103PubMedCrossRefGoogle Scholar
  20. 20.
    Grindem H, Logerstedt D, Eitzen I, Moksnes H, Axe MJ, Snyder-Mackler L, Engebretsen L, Risberg MA (2011) Single-legged hop tests as predictors of self-reported knee function in nonoperatively treated individuals with anterior cruciate ligament injury. Am J Sports Med 39(11):2347–2354PubMedCentralPubMedCrossRefGoogle Scholar
  21. 21.
    Gromping U (2006) Relative importance for linear regression in R: the package relaimpo. J Stat Softw 17(1):1–27CrossRefGoogle Scholar
  22. 22.
    Gromping U (2007) Estimators of relative importance in linear regression based on variance decomposition. Am Stat 61(2):139–147CrossRefGoogle Scholar
  23. 23.
    Harrell FE Jr (2001) Regression modeling strategies: with applications to linear models, logistic regression, and survival analysis. Springer, New YorkCrossRefGoogle Scholar
  24. 24.
    Hurd WJ, Axe MJ, Snyder-Mackler L (2008) A 10-year prospective trial of a patient management algorithm and screening examination for highly active individuals with anterior cruciate ligament injury: part 2, determinants of dynamic knee stability. Am J Sports Med 36(1):48–56PubMedCentralPubMedCrossRefGoogle Scholar
  25. 25.
    Hurd WJ, Axe MJ, Snyder-Mackler L (2008) Influence of age, gender, and injury mechanism on the development of dynamic knee stability after acute ACL rupture. J Orthop Sports Phys Ther 38(2):36–41PubMedCentralPubMedCrossRefGoogle Scholar
  26. 26.
    Iossifidou AN, Baltzopoulos V (1998) Inertial effects on the assessment of performance in isokinetic dynamometry. Int J Sports Med 19(8):567–573PubMedCrossRefGoogle Scholar
  27. 27.
    Jaric S, Radosavljevic-Jaric S, Johansson H (2002) Muscle force and muscle torque in humans require different methods when adjusting for differences in body size. Eur J Appl Physiol 87(3):304–307PubMedCrossRefGoogle Scholar
  28. 28.
    Jensen BR, Olesen AT, Pedersen MT, Kristensen J, Jens H, Remvig L, Simonsen EB, Juul-Kristensen B (2013) The effect of generalized joint hypermobility on knee function and muscle activation in children and adults. Muscle Nerve 48(5):762–769PubMedCrossRefGoogle Scholar
  29. 29.
    Johnson JW, LeBreton JM (2004) History and use of relative importance indices in organizational research. Organ Res Methods 7(3):238–257CrossRefGoogle Scholar
  30. 30.
    Jones KE, Hamilton AF, Wolpert DM (2002) Sources of signal-dependent noise during isometric force production. J Neurophysiol 88(3):1533–1544PubMedGoogle Scholar
  31. 31.
    Kurdak SS, Özgünen K, Adas Ü, Zeren C, Aslangiray B, Yazýcý Z, Korkmaz S (2005) Analysis of isokinetic knee extension/flexion in male elite adolescent wrestlers. J Sports Sci Med 4:489–498PubMedCentralPubMedGoogle Scholar
  32. 32.
    Lindeman RH, Merenda PF, Gold RZ (1980) Introduction to bivariate and multivariate analysis. Scott Foresman, GlenviewGoogle Scholar
  33. 33.
    McHugh MP, Tyler TF, Browne MG, Gleim GW, Nicholas SJ (2002) Electromyographic predictors of residual quadriceps muscle weakness after anterior cruciate ligament reconstruction. Am J Sports Med 30(3):334–339PubMedGoogle Scholar
  34. 34.
    McNair PJ, Wood GA (1993) Frequency analysis of the EMG from the quadriceps of anterior cruciate ligament deficient individuals. Electromyogr Clin Neurophysiol 33(1):43–48PubMedGoogle Scholar
  35. 35.
    Newcombe RG (1998) Two-sided confidence intervals for the single proportion: comparison of seven methods. Stat Med 17(8):857–872PubMedCrossRefGoogle Scholar
  36. 36.
    Palmieri-Smith RM, Thomas AC (2009) A neuromuscular mechanism of posttraumatic osteoarthritis associated with ACL injury. Exerc Sport Sci Rev 37(3):147–153PubMedCrossRefGoogle Scholar
  37. 37.
    Pua YH, Byrant AL, Steele JR, Newton RU, Wrigley TV (2008) Isokinetic dynamometry in anterior cruciate ligament injury and reconstruction. Ann Acad Med Singapore 37(4):330–340PubMedGoogle Scholar
  38. 38.
    Ross MD, Langford B, Whelan PJ (2002) Test-retest reliability of 4 single-leg horizontal hop tests. J Strength Cond Res 16(4):617–622PubMedGoogle Scholar
  39. 39.
    Rudolph KS, Axe MJ, Buchanan TS, Scholz JP, Snyder-Mackler L (2001) Dynamic stability in the anterior cruciate ligament deficient knee. Knee Surg Sports Traumatol Arthrosc 9(2):62–71PubMedCrossRefGoogle Scholar
  40. 40.
    Salonikidis K, Amiridis IG, Oxyzoglou N, de Villareal ES, Zafeiridis A, Kellis E (2009) Force variability during isometric wrist flexion in highly skilled and sedentary individuals. Eur J Appl Physiol 107(6):715–722PubMedCentralPubMedCrossRefGoogle Scholar
  41. 41.
    Seidler-Dobrin RD, He J, Stelmach GE (1998) Coactivation to reduce variability in the elderly. Mot Control 2(4):314–330Google Scholar
  42. 42.
    Singh NB, Arampatzis A, Duda G, Heller MO, Taylor WR (2010) Effect of fatigue on force fluctuations in knee extensors in young adults. Philos Trans A Math Phys Eng Sci 368(1920):2783–2798PubMedCrossRefGoogle Scholar
  43. 43.
    Tsepis E, Giakas G, Vagenas G, Georgoulis A (2004) Frequency content asymmetry of the isokinetic curve between ACL deficient and healthy knee. J Biomech 37(6):857–864PubMedCrossRefGoogle Scholar
  44. 44.
    Yanagawa T, Shelburne K, Serpas F, Pandy M (2002) Effect of hamstrings muscle action on stability of the ACL-deficient knee in isokinetic extension exercise. Clin Biomech (Bristol, Avon) 17(9–10):705–712CrossRefGoogle Scholar
  45. 45.
    Yao W, Fuglevand RJ, Enoka RM (2000) Motor-unit synchronization increases EMG amplitude and decreases force steadiness of simulated contractions. J Neurophysiol 83(1):441–452PubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Yong-Hao Pua
    • 1
  • Peck-Hoon Ong
    • 1
  • Jia-Ying Ho
    • 1
  • Adam L. Bryant
    • 2
  • Kate E Webster
    • 3
  • Ross A. Clark
    • 4
  1. 1.Department of PhysiotherapySingapore General HospitalSingaporeSingapore
  2. 2.Department of PhysiotherapyThe University of MelbourneMelbourneAustralia
  3. 3.School of Health Sciences ResearchLa Trobe UniversityMelbourneAustralia
  4. 4.School of Exercise ScienceAustralian Catholic UniversityMelbourneAustralia

Personalised recommendations