Biomechanics of Osteoarthritis - University of .Biomechanics of Osteoarthritis: Analyzing knee forces

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  • Biomechanics of Osteoarthritis:Analyzing knee forces and functions

    Jill Higginson, PhD

    Assistant ProfessorDepartment of Mechanical Engineering

    University of Delaware

  • Arthritis and Americans

    67 million persons2030

    46 million persons2006

  • Osteoarthritis (OA)

    Degenerative joint disease involving cartilage deteriorationThin cartilage with grooves and fragmentsDebris expedites deterioration

  • Knee osteoarthritisOA severity depends on cartilage thickness, presence of osteophytesScored on Kellgren-Lawrence (KL) scale from x-ray

    KL=0 KL=1 KL=3KL=2

  • Implications of OA

    Leading cause of disabilityLimits activities of daily living>50% of adults with OA are

  • Risk factorsModifiable

    Excess body mass Joint injury (sports, work, trauma)Occupation (due to excessive mechanical stress: hard labor, heavy lifting, knee bending, repetitive motion) Structural malalignment, muscle weakness

    Non-modifiableGender (women higher risk) Age (increases with age and levels around age 75)Race (some Asian populations have lower risk)Genetic predisposition

    Other possible risk factorsEstrogen deficiency (ERT may reduce risk of knee/hip OA)Osteoporosis (inversely related to OA)Vitamins C, E and D equivocal reports

    www.cdc.gov

  • Pathomechanics

    Andriacchi et al., 2004

  • Pathomechanics

    Andriacchi et al., 2004

  • MotivationMuscles contribute significantly to joint loads and activity can be modified with non-surgical interventionResponse to challenge may identify limiting factors (i.e. what compensatory strategies are used?)Loading patterns should be related to cartilage deterioration

  • OutlineGait analysis

    Effect of OA severity on hip, knee and ankle contributionsResponse to challenge

    Modeling and simulationJoint contact forces depend on muscle activity

    ImagingCartilage geometry vs OA progression

  • Experimental design

    ImagingCartilageMappingGait analysis

    MusculoskeletalSimulation

    JOINT CONTACT FORCES CARTILAGE GEOMETRY

  • Subject recruitmentGoal: 60 OA, 20 healthy subjects

    Age 30-85Tracked for 2 yearsNo major orthopedic, neuromuscular or cardiovascular conditions

    Bilateral x-ray (KL grade)Activity surveryStrength testing

  • Gait analysis

    Ryp

    Rxp

    mgMd

    Ryd

    RxdRzd

    ax

    ay

    az

    MpRzp

  • Gait analysisInstrumented treadmillFour walking conditions (30 sec)

    Self-selected walking speedControl speed (0.8 m/s)Fastest possible walking speed15% load carriage at SS speed

    Safety harnessGRFs, s, EMG

  • Quadriceps avoidance?

  • Quadriceps avoidance!

    (Nm/BW) Torque Volitional QuadricepsMax (Nm/BW)Moment Flexion KneePeak

    =(QE) Effort Quadriceps

  • Total support moment

    AB

  • Total support moment

  • Response to challenge

  • Response to challenge

  • From gait analysis

    Individuals with severe OA exhibitQuadriceps avoidanceReduced contribution of knee extensors to COM support (supplemented by hip)Reduced knee loads (forces and moments) when challenged to walk quickly

    What is the role of muscles in compensatory strategies?

  • Experimental design

    ImagingCartilageMappingGait analysis

    MusculoskeletalSimulation

    JOINT CONTACT FORCES CARTILAGE GEOMETRY

  • Musculoskeletal Simulation

    With inverse dynamics, we measure position, velocity and acceleration and solve for reaction forces and moments

    With forward dynamics, we estimate and apply internal (muscle) forces to solve for resultant movement patterns

  • Generation of movement

    activationdynamics

    muscletendon

    dynamics

    musculo-skeletalsystem

    movement

    CNS

    externalforces

    e(t) a(t) F(t) (t)

    ,, &&&

    http://www.designtutorials.info/images/movement-initial.jpghttp://news-service.stanford.edu/news/2007/january17/gifs/movement_golferone.jpghttp://images.google.com/imgres?imgurl=http://content.answers.com/main/content/wp/en-commons/thumb/9/9f/200px-Muybridge_race_horse_animated.gif&imgrefurl=http://www.answers.com/topic/horse&h=133&w=200&sz=183&hl=en&start=16&tbnid=PeAihaF3A4O8kM:&tbnh=69&tbnw=104&prev=/images%3Fq%3Dhorse%2Bgallop%26gbv%3D2%26hl%3Denhttp://www.pakdef.info/pakmilitary/army/siachen/siachen8.jpghttp://images.google.com/imgres?imgurl=http://www.abrsm.org/images/general/hands_playing_piano.jpg&imgrefurl=http://www.abrsm.org/%3Fpage%3Dexams/choralEnsembles/primary.html&h=179&w=272&sz=10&hl=en&start=11&tbnid=HuR3brwCymMe6M:&tbnh=74&tbnw=113&prev=/images%3Fq%3Dplaying%2Bpiano%26gbv%3D2%26hl%3Den

  • Forward dynamics simulation

    CNSactivationdynamics

    muscletendon

    dynamics

    musculo-skeletalmodel

    =M []-1

    equationsof motion

    u a FM

    ,

    e(t) a(t) F(t) (t)

    ,, &&&

  • Simulation of OA gaitMuscle-actuated forward dynamic simulationEstimate of muscle forces responsible for observed movementEnables study of muscle coordination patternsAsymmetry in observed movement and underlying muscle control

    www.simtk.org

  • Simulation results

    Predicted reduction in quadriceps excitation and forceon more involved side.

  • Joint contact force

    Inverse dynamics(F 100% BW)

    Forward dynamics(F 200% BW)

  • From simulations

    Estimates of muscle forces and joint contact forcePredict muscle coordination patternsHighlight muscle compensatory strategies

  • Experimental design

    ImagingCartilageMappingGait analysis

    MusculoskeletalSimulation

    JOINT CONTACT FORCES CARTILAGE GEOMETRY

  • Static weight-bearing MRI

    Upright

    Tilt 45Knee 0

    Tilt 45Knee 15

    Tilt 45Knee 30

    Image segmentation,cartilage mapping

    tibio-femoral kinematics

    Fonar upright open-MRI

  • Results Healthy knees

    Cartilage centroid location moves distally with knee flexion

  • Results OA knees

    Cartilage contact area and centroid location depends on OA severity

  • From imaging studies

    Novel weight-bearing MRICartilage mapping illustrates loss of cartilage area and abnormal contact patternsIncreased tibio-femoral translations

  • Experimental design

    ImagingCartilageMappingGait analysis

    MusculoskeletalSimulation

    JOINT CONTACT FORCES CARTILAGE GEOMETRY

  • Summary

    Abnormal loading patterns for OA kneesAbnormal cartilage geometryKnee forces and functions

    Depend on muscle coordinationImplications for other joints too!

    Muscle coordination patterns can be modified

  • Research questions

    Do abnormal forces lead to abnormal cartilage geometry?Are compensatory strategies beneficial or detrimental to OA progression?Do OA copers and non-copers exist?Can non-surgical interventions help?

    Longitudinal study of OA progression

  • OA research at UDMulti-disciplinary study funded by NIH to address the mechanisms of OA prevention, progression and treatmentInvestigators from mechanical engineering, physical therapy, biology, health and exercise scienceUnique focus on mentoring women in science and engineering

  • OA research at UDPerlecan and Heparanase in Cartilage Growth and Healing(PI: Cindy Farach-Carson)

    Solute Transport in the Subchondral Bone Plate of Osteoarthritic Joints (PI: Liyun Wang)

    Risk Factors for Progression of Knee OA(PI: Jill Higginson)

    Joint Loading and the Progression of Osteoarthritisfollowing Total Knee Arthroplasty (PI: Lynn Snyder-Mackler)

    Knee Stiffness, Proprioception and Instability affect Knee Controlin OA (PI: Katy Rudolph)

  • AcknowledgementsNeuromuscular Biomechanics Laboratory

    Joseph Zeni, Jr. Andy KubinskiMing Xiao Shridhar ShahChris Henderson Ben Roewer

    CollaboratorsPeter Barrance, PhD

    MentorsThomas Buchanan, PhDLynn Snyder-Mackler, PT, PhD

    Research subjects!Martha Callahan

    FundingNIH 2P20-RR16458

    Biomechanics of Osteoarthritis:Analyzing knee forces and functionsArthritis and AmericansOsteoarthritis (OA)Knee osteoarthritisImplications of OARisk factorsPathomechanicsPathomechanicsMotivationOutlineExperimental designSubject recruitmentGait analysisGait analysisQuadriceps avoidance?Quadriceps avoidance!Total support momentTotal support momentResponse to challengeResponse to challengeFrom gait analysisExperimental designMusculoskeletal SimulationGeneration of movementForward dynamics simulationSimulation of OA gaitSimulation resultsJoint contact forceFrom simulationsExperimental designStatic weight-bearing MRIResults Healthy kneesResults OA kneesFrom imaging studiesExperimental designSummaryResearch questionsOA research at UDOA research at UDAcknowledgements