Verbal Instruction Reduces Patellofemoral Joint Loading During Bodyweight Squatting

in Journal of Sport Rehabilitation
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Context: The bodyweight squat exercise is a common component for treatment and prevention of patellofemoral pain; however, it can also place a high load on the patellofemoral joint. Restricting anterior motion of the knees relative to the toes during squatting appears to reduce patellofemoral loading. However, exercise professionals typically rely on verbal instructions to alter squat technique. Objective: To evaluate the influence of verbal instructions regarding squat technique on patellofemoral joint loading. Design: Cross-sectional study. Setting: Motion analysis laboratory. Participants: Eleven uninjured females. Intervention: Participants performed bodyweight squats before (baseline) and after receiving verbal instructions to limit anterior knee motion. Two different types of verbal instruction were used, one intended to promote an internal focus of attention and the other intended to promote an external focus of attention. Three-dimensional kinematics and kinetics were recorded using a multicamera system and force plate. Main Outcome Measures: Sagittal plane patellofemoral joint forces and stress were estimated using a musculoskeletal model. Results: Participants demonstrated a reduction in patellofemoral joint forces (35.4 vs 31.3 N/kg; P = .01) and stress (10.7 vs 9.2 mPa; P = .002) after receiving instructions promoting an internal focus of attention, compared with their baseline trials. Participants also demonstrated a reduction in patellofemoral joint forces (35.4 vs 32.3 N/kg; P = .03) and stress (10.7 vs 9.6 mPa; P = .04) after receiving instructions promoting an external focus of attention (vs baseline). However, there were no significant differences in patellofemoral forces (P = .84) or stress (P = .41) for trials performed with an internal versus external attentional focus. Conclusion: It appears that verbal instruction regarding knee position influences patellofemoral joint loading during squatting.

The authors are with Physical Therapy Program, Rinker-Ross School of Health Sciences, Trine University, Fort Wayne, IN, USA.

Almonroeder (almonroedert@trine.edu) is corresponding author.
Journal of Sport Rehabilitation
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References
  • 1.

    Boling MPadua DMarshall SGuskiewicz KPyne SBeutler A. Gender differences in the incidence and prevalence of patellofemoral pain syndrome. Scand J Med Sci Sports. 2010;20(5):725730. PubMed ID: 19765240 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    Taunton JERyan MBClement DBMcKenzie DCLloyd-Smith DRZumbo BD. A retrospective case-control analysis of 2002 running injuries. Br J Sports Med. 2002;36(2):95101. PubMed ID: 11916889 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3.

    Rathleff MSRathleff CROlesen JLRasmussen SRoos EM. Is knee pain during adolescence a self-limiting condition? Prognosis of patellofemoral pain and other types of knee pain. Am J Sports Med. 2016;44(5):11651171. PubMed ID: 26792702 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4.

    Conchie HClark DMetcalfe AEldridge JWhitehouse M. Adolescent knee pain and patellar dislocations are associated with patellofemoral osteoarthritis in adulthood: a case control study. Knee. 2016;23(4):708711. PubMed ID: 27180253 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Utting MRDavies GNewman JH. Is anterior knee pain a predisposing factor to patellofemoral osteoarthritis? Knee. 2005;12(5):362365. PubMed ID: 16146626 doi:

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Brechter JPowers CM. Patellofemoral stress during walking in persons with and without patellofemoral pain. Med Sci Sports Exerc. 2002;34(10):15821593. doi:

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Farrokhi SKeyak JHPowers CM. Individuals with patellofemoral pain exhibit greater patellofemoral joint stress: a finite element analysis study. Osteoarthritis Cartilage. 2011;19(3):287294. PubMed ID: 21172445 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8.

    Peng HTChen WCKernozek TWKim KSong CY. Influences of patellofemoral pain and fatigue in female dancers during ballet jump-landing. Int J Sports Med. 2015;36(9):747753. PubMed ID: 25806586 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9.

    Thomeer LTSheehan FTJackson JN. Normalized patellofemoral joint reaction force is greater in individuals with patellofemoral pain. J Biomech. 2017;60:238242. PubMed ID: 28755815 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10.

    Kooiker LVan De Port IGWeir AMoen MH. Effects of physical therapist–guided quadriceps-strengthening exercises for the treatment of patellofemoral pain syndrome: a systematic review. J Orthop Sports Phys Ther. 2014;44(6):391B1. PubMed ID: 24766358 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11.

    Bolgla LMalone T. Exercise prescription and patellofemoral pain: evidence for rehabilitation. J Sport Rehabil. 2005;14:7288. doi:

  • 12.

    Wallace DASalem GJSalinas RPowers CM. Patellofemoral joint kinetics while squatting with and without an external load. J Orthop Sports Phys Ther. 2002;32(4):141148. PubMed ID: 11949662 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13.

    Chandler JMcMillan JKibler WBRichards D. Safety of the squat exercise. ACSM Curr Comment. 2002.

  • 14.

    Sands WAWurth JJHewit JK. Basics of Strength and Conditioning Manual. Colorado Springs, CO: National Strength and Conditioning Association; 2012.

    • Search Google Scholar
    • Export Citation
  • 15.

    Schoenfeld BJ. Squatting kinematics and kinetics and their application to exercise performance. J Strength Cond Res. 2010;24(12):34973506. PubMed ID: 20182386 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Kernozek TWGheidi NZellmer MHove JHeinert BLTorry MR. Effects of anterior knee displacement during squatting on patellofemoral joint stress. J Sport Rehabil. 2018;27(3):237243. doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Hunt CPaez AFolmar E. The impact of attentional focus on the treatment of musculoskeletal and movement disorders. Int J Sports Phys Ther. 2017;12(6):901907. PubMed ID: 29158952 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 18.

    Wulf GShea CLewthwaite R. Motor skill learning and performance: a review of influential factors. Med Educ. 2010;44(1):7584. PubMed ID: 20078758 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19.

    Durham KVan Vliet PMBadger FSackley C. Use of information feedback and attentional focus of feedback in treating the person with a hemiplegic arm. Physiother Res Int. 2009;14(2):7790. PubMed ID: 19107706 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20.

    Johnson LBurridge JHDemain SH. Internal and external focus of attention during gait re-education: an observational study of physical therapist practice in stroke rehabilitation. Phys Ther. 2013;93(7):957966. PubMed ID: 23559523 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 21.

    Abdollahipour RWulf GPsotta RPalomo Nieto M. Performance of gymnastics skill benefits from an external focus of attention. J Sports Sci. 2015;33(17):18071813. PubMed ID: 25774536 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 22.

    Halperin IWilliams KJMartin DTChapman DW. The effects of attentional focusing instructions on force production during the isometric midthigh pull. J Strength Cond Res. 2016;30(4):919923. PubMed ID: 27003451 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 23.

    Porter JMNolan RPOstrowski EJWulf G. Directing attention externally enhances agility performance: a qualitative and quantitative analysis of the efficacy of using verbal instructions to focus attention. Front Psychol. 2010;1:216. PubMed ID: 21833271 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24.

    Schutts KSWu WFWVidal ADHiegel JBecker J. Does focus of attention improve snatch lift kinematics? J Strength Cond Res. 2017;31(10):27582764. PubMed ID: 28030531 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 25.

    Wulf GDufek JSLozano LPettigrew C. Increased jump height and reduced EMG activity with an external focus. Hum Mov Sci. 2010;29(3):440448. PubMed ID: 20409600 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 26.

    Cohen J. Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Hillsdale, NJ: L. Erlbaum Associates; 1988.

  • 27.

    Faul FErdfelder ELang AGBuchner A. G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007;39(2):175191. PubMed ID: 17695343 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 28.

    Benjaminse AGokeler ADowling AVet al. Optimization of the anterior cruciate ligament injury prevention paradigm: novel feedback techniques to enhance motor learning and reduce injury risk. J Orthop Sports Phys Ther. 2015;45(3):170182. PubMed ID: 25627151 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 29.

    Bell ALPedersen DRBrand RA. Prediction of hip joint center location from external landmarks. Hum Mov Sci. 1989;8:316. doi:

  • 30.

    Bell ALPedersen DRBrand RA. A comparison of the accuracy of several hip center location prediction methods. J Biomech. 1990;23(6):617621. PubMed ID: 2341423 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 31.

    Grood ESSuntay WJ. A joint coordinate system for the clinical description of three-dimensional motions: application to the knee. J Biomech Eng. 1983;105(2):136144. PubMed ID: 6865355 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 32.

    Dempster WT. Space requirements of the seated operator: geometrical, kinematic, and mechanical aspects of the body with special reference to the limbs. Technical Report WADC-TR-55-159. 1955;55159.

    • Export Citation
  • 33.

    van Eijden TMWeijs WAKouwenhoven EVerburg J. Forces acting on the patella during maximal voluntary contraction of the quadriceps femoris muscle at different knee flexion/extension angles. Acta Anat. 1987;129(4):310314. PubMed ID: 3630619 doi:

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 34.

    Powers CMLilley JCLee TQ. The effects of axial and multi-plane loading of the extensor mechanism on the patellofemoral joint. Clin Biomech. 1998;13(8):616624. doi:

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 35.

    Cohen J. A power primer. Psychol Bull. 1992;112(1):155159. PubMed ID: 19565683 doi:

  • 36.

    Varghese RHui-Chan CWYWang EBhatt T. Internal consistency and test-retest reliability of an instrumented functional reaching task using wireless electromyographic sensors. J Electromyogr Kinesiol. 2014;24:593600. PubMed ID: 25026882 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 37.

    Escamilla RFZheng NMacleod TDet al. Patellofemoral joint force and stress during the wall squat and one-leg squat. Med Sci Sports Exerc. 2009;41(4):879888. PubMed ID: 19276845 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 38.

    Barrios JWillson J. Minimum detectable change in medial tibiofemoral contact force parameters: derivation and application to a load-altering intervention. J Appl Biomech. 2017;33(2):171175. PubMed ID: 27834573 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 39.

    Fry ACSmith JCSchilling BK. Effect of knee position on hip and knee torques during the barbell squat. J Strength Cond Res. 2003;17(4):629633. PubMed ID: 14636100

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 40.

    Lorenzetti SGulay TStoop Met al. Comparison of the angles and corresponding moments in the knee and hip during restricted and unrestricted squats. J Strength Cond Res. 2012;26(10):28292836. PubMed ID: 22801421 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 41.

    Farrokhi SPollard CDSouza RBChen YReischl SPowers CM. Trunk position influences the kinematics, kinetics, and muscle activity of the lead lower extremity during the forward lunge exercise. J Orthop Sports Phys Ther. 2008;38(7):403409. PubMed ID: 18591759 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 42.

    Teng HPowers CM. Sagittal plane trunk posture influences patellofemoral joint stress during running. J Orthop Sports Phys Ther. 2014;44(10):785792. PubMed ID: 25155651 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 43.

    Lohse KRSherwood DE. Thinking about muscles: the neuromuscular effects of attentional focus on accuracy and fatigue. Acta Psychol. 2012;140(3):236245. doi:

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 44.

    Nunes GSSilva RSdos Santoa AFFernandes RASSerrao FVde Noronha M. Methods to assess patellofemoral joint stress: a systematic review. Gait Posture. 2018;61:188196. PubMed ID: 29353744 doi:

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
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