Knee Surgery, Sports Traumatology, Arthroscopy

, Volume 24, Issue 1, pp 279–286 | Cite as

A novel clinical approach for assessing hop landing strategies: a 2D telescopic inverted pendulum (TIP) model

  • Robert Letchford
  • Kate Button
  • Paul Adamson
  • Paulien E. Roos
  • Valerie Sparkes
  • Robert W. M. van Deursen



Single leg hop for distance is used to inform rehabilitation and return to sport following anterior cruciate ligament reconstruction. However, impairment of landing mechanics may persist after the recommended performance parameter (hop distance) has been met; therefore, alternative methods are required. This study follows the COSMIN guideline to investigate the measurement properties of data from a new instrument (2D TIP). This is a simple motion analysis instrument to assess landing strategy based on more complex biomechanical modelling.


Data collected in the clinical setting from 30 subjects with chronic ACL deficiency (mean 15.5, SD 4.3 months following injury) before and 6 months after ACL reconstruction and a healthy control group were analysed. Reliability and measurement error were calculated using two repeated measures from three independent raters. Construct validity was assessed by hypothesis testing, and known groups validity and responsiveness were defined by differences between groups.


The data demonstrate excellent inter-rater (ICC = 0.81–1.00) and intra-rater (ICC = 0.85–1.00) reliability with low measurement error. Of the eight construct validity hypothesis, six were fully and two partially supported. Between-group differences were significant (P < 0.05) supporting the validity and responsiveness hypothesis.


2D TIP is a simple and inexpensive instrument for assessing landing strategy that has demonstrated appropriate reliability, validity and responsiveness in the ACL-injured population. The instrument will now be used to identify altered movement strategies and develop novel rehabilitation interventions that target strategy and performance.

Level of evidence

Prospective diagnostic study, Level II.


Knee ACL Clinical biomechanics Movement analysis Rehabilitation Physiotherapy 



The project received funding from a Research Capacity Building Collaboration Wales PhD Fellowship.

Conflict of interest

The authors listed on this manuscript have no affiliations with or involvement in any organisation or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership or other equity interest; and expert testimony or patent-licensing arrangements) or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.

Ethical standards and institutional review board

Informed consent was obtained from each subject, and the rights of the subjects were protected in accordance with the 1964 Declaration of Helsinki and the favourable ethical opinion provided by the South East Wales Research Ethics Committee (Reg: 10/WSE04/48).


  1. 1.
    Adams D, Logerstedt D, Hunter-Giordano A, Axe MJ, Snyder-Mackler L (2012) Current concepts for anterior cruciate ligament reconstruction: a criterion based rehabilitation progression. J Orthop Sports Phys Ther 42:601–614PubMedPubMedCentralCrossRefGoogle Scholar
  2. 2.
    Andriacchi TP, Koo S, Scanlan SF (2009) Gait mechanics influence healthy cartilage morphology and osteoarthritis of the knee. J Bone Joint Surg Am 91(Suppl 1):95–101PubMedPubMedCentralCrossRefGoogle Scholar
  3. 3.
    Augustsson J, Thomee R, Linden C, Folkesson M, Tranberg R, Karlsson J (2006) Single leg hop tests following fatiguing exercise: reliability and biomechanical analysis. Scand J Med Sci Sports 16:111–120PubMedCrossRefGoogle Scholar
  4. 4.
    Benoit DL, Ramsey DK, Lamontagne M, Xu L, Wrentenberg P, Renstrom P (2006) Effect of skin movement artefact on knee kinematics during gait and cutting motions measured in vivo. Gait Posture 24:152–164PubMedCrossRefGoogle Scholar
  5. 5.
    Button K, van Deursen RWM, Price P (2005) Measurement of functional recovery in individuals with acute anterior cruciate ligament rupture. Br J Sports Med 39:866–871PubMedPubMedCentralCrossRefGoogle Scholar
  6. 6.
    Button K, Roos P, van Deursen RWM (2013) Activity progression for anterior cruciate ligament reconstructed individuals. Clin Biomech 29:206–212CrossRefGoogle Scholar
  7. 7.
    Cappozzo A, Catani F, Leardini A, Beneditti MG, Croce UD (1996) Position and orientation in space of bones during movement: experimental artefacts. Clin Biomech 11:90–100CrossRefGoogle Scholar
  8. 8.
    Deneweth JM, Bey MJ, Mclean SG, Lock TR, Kolowich PA, Tashman S (2010) Tibiofemoral joint kinematics of the anterior cruciate ligament-reconstructed knee during a single-legged hop landing. Am J Sports Med 38:1820–1828PubMedCrossRefGoogle Scholar
  9. 9.
    DeVet HCW, Terwee CB, Mokkink LB, Knol DL (2011) Measurement in medicine. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  10. 10.
    Engelen-van Melick N, van Cingel REH, Tijssen MPW, Nijhuis-van der Sanden MWG (2013) Assessment of functional performance after anterior cruciate ligament reconstruction: a systematic review of measurement procedures. Knee Surg Sports Traumatol Arthrosc 21:869–879PubMedCrossRefGoogle Scholar
  11. 11.
    Fitzgerald GK, Lephart SM, Hwang JH, Wainner MRS (2001) Hop tests as predictors of dynamic stability. J Orthop Sports Phys Ther 31:588–597PubMedCrossRefGoogle Scholar
  12. 12.
    Gokeler A, Hof AL, Arnold MP, Dijkstra PU, Postema K, Otten E (2010) Abnormal landing strategies after ACL reconstruction. Scand J Med Sci Sports 20:e12–e19PubMedCrossRefGoogle Scholar
  13. 13.
    Gorton GE, Herbert DA, Gannotti ME (2001) Assessment of the kinematic variability among 12 motion analysis laboratories. Gait Posture 29:398–402CrossRefGoogle Scholar
  14. 14.
    Grindem H, Logerstedt D, Eitzen I, Mosknes H, Axe MJ, Snyder-Mackler L, Engerbretsen L, Risberg MA (2011) Single leg hop tests as predictors of self reported knee function in non operatively treated individuals with anterior cruciate ligament injury. Am J Sports Med 39:2347–2354PubMedPubMedCentralCrossRefGoogle Scholar
  15. 15.
    Gustavsson A, Neeter C, Thomeé P, Silbernagel KG, Augustsson J, Thomeé R, Karlsson J (2006) A test battery for evaluating hop performance in patients with an ACL injury and patients who have undergone ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 14:778–788PubMedCrossRefGoogle Scholar
  16. 16.
    Hopper DM, Goh SC, Wentworth LA, Chan DYK, Chau JHW, Wooton GL, Strauss GR, Boyle JJW (2002) Test retest reliability of knee rating scales and functional hop tests one year following anterior cruciate ligament reconstruction. Phys Ther Sport 3:10–18CrossRefGoogle Scholar
  17. 17.
    Kvist JEKA, Sporrstedt K, Good L (2005) Fear of re-injury: a hindrance for returning to sports after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 13:393–397PubMedCrossRefGoogle Scholar
  18. 18.
    Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics 33:159–174PubMedCrossRefGoogle Scholar
  19. 19.
    Logerstedt D, Grindem H, Lynch A, Eitzen I, Engerbretsen L, Risberg MA, Axe MJ, Snyder-Mackler L (2012) Single leg hop tests as predictors of self-reported knee function after anterior cruciate ligament reconstruction. Am J Sports Med 40:2348–2356PubMedPubMedCentralCrossRefGoogle Scholar
  20. 20.
    Mazza C, Stanhop SJ, Taviani A, Cuppozzo A (2006) Biomechanical modelling of sit to stand to upright posture for mobility assessment of persons with chronic stroke. Arch Phys Med Rehabil 87:635–641PubMedCrossRefGoogle Scholar
  21. 21.
    Oberlander KD, Bruggemann GP, Hoher J, Karamanidis K (2013) Altered landing mechanics in ACL-reconstructed patients. Med Sci Sports Exerc 45:506–513PubMedCrossRefGoogle Scholar
  22. 22.
    Oberlander KD, Bruggemann GP, Hoher J, Karamanidis K (2012) Reduced knee joint moment in ACL deficient patients at a cost of dynamic stability during landing. J Biomech 45:1387–1392PubMedCrossRefGoogle Scholar
  23. 23.
    Orishimo KF, Kremenic IJ, Mullaney MJ, Mchugh MP, Nicholas SJ (2010) Adaptations in single-leg hop biomechanics following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 18:1587–1593PubMedCrossRefGoogle Scholar
  24. 24.
    Papa E, Cappozzo A (1999) A telescopic inverted-pendulum model of the musculoskeletal system and its use for the analysis of the sit to stand motor task. J Biomech 32:1205–1212PubMedCrossRefGoogle Scholar
  25. 25.
    Papa E, Cappozzo A (2000) Sit to stand motor strategies investigated in able bodied young and elderly subjects. J Biomech 33:1113–1122PubMedCrossRefGoogle Scholar
  26. 26.
    Paterno MV, Greenberger HB (1996) The test retest reliability of a one legged hop for distance in young adults with and without ACL reconstruction. Isokinet Exerc Sci 6:1–6Google Scholar
  27. 27.
    Phillips N, van Deursen RWM (2008) Landing stability in anterior cruciate ligament deficiency versus healthy individuals: a motor control approach. Phys Ther Sport 9:193–201PubMedCrossRefGoogle Scholar
  28. 28.
    Reid A, Birmingham TB, Stratford PW, Alcock GK, Giffin JR (2007) Hop tests provides a reliable and valid outcome measure during rehabilitation after anterior cruciate ligament reconstruction. Phys Ther 87:337–349PubMedCrossRefGoogle Scholar
  29. 29.
    Reinke E, Spindler KP, Lorring D, Jones MH, Schmitz L, Flanigan DC et al (2011) Hop tests correlate with IKDC and KOOS at minimum of 2 years after primary ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 19:1806–1816PubMedPubMedCentralCrossRefGoogle Scholar
  30. 30.
    Risberg MA, Mosknes H, Storevold A, Holm I, Snyder-Mackler L (2009) Rehabilitation after anterior cruciate ligament injury influences joint loading during walking but not hopping. Br J Sports Med 43:423–428PubMedPubMedCentralCrossRefGoogle Scholar
  31. 31.
    Roos PE, Button K, Sparkes V, van Deursen RWM (2013) Altered biomechanical strategies and medio-lateral control of the knee represent incomplete recovery of individuals with ACL injury during single leg hop. J Biomech 47:675–680PubMedCrossRefGoogle Scholar
  32. 32.
    Rudolph KS, Axe MJ, Snyder-Mackler L (2000) Dynamic stability after ACL injury: who can hop? Knee Surg Sports Traumatol Arthrosc 8:262–269PubMedCrossRefGoogle Scholar
  33. 33.
    Schwartz MH, Trost J, Wervey RA (2004) Measurement and management of errors in quantitative gait data. Gait Posture 20:196–203PubMedCrossRefGoogle Scholar
  34. 34.
    Tegner Y, Lysholm J (1985) Rating systems in the evaluation of knee ligament injuries. Clin Orthop Relat Res 198:43–49PubMedGoogle Scholar
  35. 35.
    Thomee R, Kaplan Y, Kvist J, Mykleburst G, Risberg A, Theisen D et al (2011) Muscle strength and hop performance criteria prior to return to sport after ACLR. Knee Surg Sports Traumatol Arthrosc 19:1798–1805PubMedCrossRefGoogle Scholar
  36. 36.
    van Deursen R, Phillips N (2006) Landing style differences between anterior cruciate ligament deficient and healthy subjects. J Biomech 39:S178CrossRefGoogle Scholar
  37. 37.
    Waaijman R, Bus SA (2012) The interdependency of peak pressure and pressure time integral in pressure studies on diabetic footwear: no need to report both parameters. Gait Posture 35:1–5PubMedCrossRefGoogle Scholar
  38. 38.
    Winter DA (2009) Biomechanics and motor control of human movement, 4th edn. Willey, New JerseyCrossRefGoogle Scholar

Copyright information

© European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2014

Authors and Affiliations

  • Robert Letchford
    • 1
    • 3
  • Kate Button
    • 1
    • 2
    • 4
  • Paul Adamson
    • 1
    • 2
    • 4
  • Paulien E. Roos
    • 1
    • 2
  • Valerie Sparkes
    • 1
    • 2
  • Robert W. M. van Deursen
    • 1
    • 2
  1. 1.School of Healthcare SciencesCardiff UniversityCardiffUK
  2. 2.Arthritis Research UK Biomechanics and Bioengineering CentreCardiff UniversityCardiffUK
  3. 3.Aneurin Bevan Health Board, Physiotherapy DepartmentRoyal Gwent HospitalNewport, GwentUK
  4. 4.Cardiff and Vale University Health Board, Physiotherapy DepartmentUniversity Hospital of WalesCardiffUK

Personalised recommendations