Structure & Function of the Knee - MCCC

1 Structure & Function of the KneeOne of the most complex simple structures in the human middle child of the lower the KneeDistal femurRight Femur(ADDuctortubercle)Osteologyof the KneeThe proximal tibia & fibulaThe medial and lateral condylesof the tibia form the shallow articulations with the distal femurThe intercondylar/intercondyloideminence the attachment point for the cruciateligamentsTibialTuberosityFibular HeadInterosseousMembraneAnatomy of the knee : Anterior Aspect Femur Medial Condyle ArticularCartilage Quadriceps Tendon Tibia TibialPlateau TibialTuberosity Patellar Tendon Fibula Medial Meniscus Lateral Meniscus Medial collateral ligament Lateral collateral LigamentAnatomy of the knee : Posterior Aspect Femur Medial condyle Lateral condyle ADDuctorTubercle Tibia Tibialplateau Fibula Fibular Head Medial Meniscus Lateral Meniscus Posterior CruciateLigament Lateral collateral ligament Medial collateral ligament PoplitealspaceAnatomy of the KneeCruciateLigamentsAnterior: (ACL)-resists anterior motion of the tibia on a fixed femur-resists extremes of knee extensionPosterior: (PCL)-resists posterior motion of the tibia on a fixed femur-resists extremes of knee flexionAnatomy of the knee : Genu what?

2 Genuvalgumrefers to a frontal deviation of the position of the referred to as knock- knee due to the medial displacement of the kneeGenuvarumrefers to a frontal deviation of the position of the referred to as bow-leg Anatomy of the knee : Genu what? Genurecurvatum:Hyperextension of the tibiofemoraljoint placing excessive stress on the structures in the poplitealspaceTibialnervePoplitealVeinPo plitealArteryCommon PeronealNerveCommon Pathologies of the KneeChondromalaciaof the PatellaOsgood-Schlatter sDiseaseCommon Pathologies of the KneeThe menisci:absorb shock and disperse large compressive forces through the knee jointThey may not heal well:inner 1/3: avascular(a)middle 1/3: poor blood supply (b)outer 1/3: good blood supply (c)Myologyof the KneeYour subtopic goes hereRectus FemorisOriginAnterior-inferior iliac spineInsertionTibialtuberosityvia the quadriceps tendonInnervationFemoraln.

3 ActionHipflexion, knee extension tidbit One of the heads of the quads Myologyof the KneeVastusMedialisOriginMedial lip of the lineaasperaand the intertrochanteridline of the femurInsertionTibialtuberosityvia the patellar tendonInnervationFemoral extension tidbit One of the heads of the quad VMO one of the first musclesof the knee to atrophy post-operatively, responsible for last 10-15oof knee extensionVastusMedialisObliquusMyologyof the KneeVastusLateralisOriginLateral lip of the lineaaspera,intertrochantericline, lateral region of the glutealtuberosityInsertionTibialtuberosi tyvia the patellar tendonInnervationFemoral n. ActionKnee extension tidbit Partof the quads Myologyof the KneeVastusIntermediusOriginUpper 2/3 of the anterior femoral shaftInsertionTibialtuberosityvia the patellartendonInnervationFemoral extensionQ Angle of the KneeThe line of force of the quadriceps can be described by the Q-angle.

4 It identifies :-greater angle-greater incidence of patellofemoraljoint painQAngleCompression at the PatellofemoralJointThe Patella:-also known as the knee cap, is a thick, circular-triangular bone which articulates with the femur and covers and protects the anterior articularsurface of the kneeActivityForce% Body WeightPounds of ForceWalking850 N1/2 x BW100 lbsBike850 N1/2 x BW100 lbsStair Ascend1500 x BW660 lbsStair Descend4000 N5 x BW1000 lbsJogging5000 N7 x BW1400 lbsSquatting5000 N7 x BW1400 lbsDeep Squatting15000 N20 x BW4000 lbsTo Squat or not to Squat?Alignment is the keyBalance among the heads of the quads is critical to the health of your kneesMyologyof the KneeYour subtopic goes hereSemitendinosusOriginIschialtuberosit yInsertionProximal-medialsurface of the tibia (pesanserinus)InnervationTibialportion of the sciatic extension, knee flexion, tidbit One of the hamstringsMyologyof the KneeYour subtopic goes hereBiceps FemorisOriginIschialtuberosityInsertionH ead ofthe fibulaInnervationTibialportion of the sciatic extension, kneeflexion tidbit One of the hamstringsAA B C DBicep F Bicep F SemimemSemitenMyologyof the KneeYour subtopic goes hereSemimembranosusOriginIschialtuberosi tyInsertionMedial condyleof the tibia, posterior aspectInnervationTibialportion of the sciatic extension, knee flexion tidbit One of the hamstringsMyologyof the KneeYour subtopic goes hereSartoriusOriginASISI nsertionProximal-medial surface of the tibia (via the pesanserinus)

5 InnervationFemoral flexion, hip ABD, Hip ER, knee flexion tidbit Longest muscle in the bodyMyologyof the KneeYour subtopic goes hereGracillisOriginBody and inferior ramusof the pubisInsertionProximal-medial aspect of the tibia (pesanserinus)InnervationObturatorn. ActionHip ADD, hip flexion, knee flexionWhat is the PesAnserinus?The semitendinosus, sartoriusand gracillisall attach to the proximalmedial tibia through a broad sheet of connectivetissue known as the 3 muscles:-originate from different bones on the pelvis-perform different actions at the hip-are innervated by differentnervesThe all perform the following at the knee :-flexion-medial stabilityMyologyof the KneePopliteusOriginPosterior aspect of the lateral femoral condyleInsertionPosteriorsurface of the proximal flexionMyologyof the KneeGastrocnemiusOriginMedial head: posterioraspect of the medial femoral condyleLateral head: posterior aspect of the lateral femoral condyleInsertionCalcanealtuberosityviath e Achilles the knee , plantar flexion, What can you identify?

6 (in her knee )QuadricepsVastusmedialisVastuslater alisVastusintermedius?Rectus femorisSartoriusAnything else?