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Dr. Pukhrambam Ratan khuman (PT)

M.P.T., (Ortho & Sports)


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introduction

Participating bones

Femur

Tibia

Patella

13 August 2013 Dr. Ratankhuman M.P.T., (Ortho & Sports) 2


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Knee complex

Tibio-femoral joint

Patello-femoral joint



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Tibio-femoral/Knee joint

Ginglymus(Hinge) ?

A freely moving joint in which the bones are so

articulated as to allow extensive movement in

one plane. Arthodial(Gliding) ?

6 degrees of freedom

3 Rotations

3 Translations



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Knee degree of freedom

Rotations

Flex/Ext1501400

Varus/Valgus6080 in extension

Int/ext rotation250300 in flexion

Translations

AP 5 - 10mm

Compression/Distraction 2 - 5mm Medial/Lateral 1-2mm



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General Features of

Tibio-femoral Joint Double condyloid knee joint is also referred to as

Medial & Lateral Compartmentsof the knee.

Double condyloid joint with 30 freedom ofAngular(Rotatory) motion.

Flexion/Extension PlaneSagittal plane

AxisCoronal axis

Medial/lateral (int/ext) rotation PlaneTransverse plane

AxisLongitudinal axis

Abduction/Adduction PlaneFrontal plane

AxisAntero-posterior axis.



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Femoral articular surface

Femur is proximal articular surface of the knee

joint with large medial & lateral condyles.

Because of obliquity of shaft, the femoral

condyles do not lie immediately below the

femoral head but are slightly medial to it.

The medial condyle extend further distally, so

that, despite the angulation of the femurs shaft,the distal end of the femur remains essentially

horizontal.



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In sagittal plane - Condyles have a convex shape

In the frontal plane - Slight convexity

The lateral femoral condyle

Shifted anteriorly in relation to medial Articular surface is shorter

Inferiorly, the lateral condyle appears to be longer

Two condyles are separated

Inferiorly by Intercondylar notch

Anteriorly by an asymmetrical, shallow groove called

the Patellar Groove or Surface



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9o

The tibial plateaus are predominantly

flat, but convexity at anterior &

posterior margins

Because of this lack of bony stability,

accessory joint structures (menisci) are

necessary to improve joint congruency.



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Menisci of knee joint

2 asymmetrical fibro cartilaginous joint diskcalled Menisci are located on tibial plateau.

The medial meniscus is a semicircle & the

lateral is 4/5 of a ring (Williams, PL, 1995).



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Both menisci are

Open towards intercondylararea

Thick peripherally Thin centrally forming

cavities for femoral condyle

By increasing congruence,

menisci play in reducingfriction between the jointsegment & serve as shockabsorber.



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Meniscal attachment

Common attachment of medial & lateral

Intercondylar tubercles of the tibia

Tibial condyle via coronary ligaments

Patella via patellomeniscal or patellofemoral ligament

Transverse ligament between two menisci

Anterior cruciate ligament (ACL)



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Meniscal attachment

Unique attachment of medial menisci

Medial collateral ligament (MCL)

Semitendinous muscle

Unique attachment of lateral menisci

Anterior & posterior meniscofemoral ligament

Posterior cruciate ligament (PCL)

Popliteus muscle



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Young children whose menisci have ample

of blood supply have low incidence of injury

In adult, only the peripheral vascularized

region is capable of inflammation, repair &remodeling following a tearing injury.

Menisci are well innervated with free nerve

ending & 3 mechanoreceptors (Ruffinecorpuscle, Pacinian corpuscle & Golgi tendon organs)



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TF alignment & weight

bearing force

The anatomic/ longitudinal axis

FemurOblique, directed inferiorly & medially

TibiaDirected vertically

The femoral & tibial longitudinal axis form an anglemedially at the knee joint of 18501900, i.e. 50100

creating Physiological Valgus at knee

In bilateral static stanceequal weight

distribution on medial & lateral condyle



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Deviation in normal force distribution

TF angle > 1900Genu Valgumcompress

lateral condyle

TF angle < 1800Genu Varumcompressmedial condyle

Compressive force in dynamic knee joint

23 time body weight in normal gait 56 time body weight in activities (like

Running, Stair Climbing etc.)



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Knee joint capsule

Joint capsule encloseTF & PF is large lax

Outer portionfirmly attached to the inferioraspect of femur & superior portion of tibia.

Posterior attachment Proximally to posterior margins of the femoral

condyles and intercondylar notch.

Distally to posterior tibial condyle.

Anterior attachment

SuperiorlyPatella, tendon of quadriceps muscles Inferiorly patellar tendon complete the anterior

portion of the joint capsule.



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The antero-medial & antero-lateral portions

of the capsule, are often separately identified

as the medial and lateral patellar

retinaculae or together as the extensorretinaculum.

The joint capsule is reinforced medially,

laterally & posteriorly by capsular ligaments.



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Extensor retinaculum

2 layerssuperficial & deeper

Deeper layer

Connecting the capsule anteriorly to menisci &

tibia via coronary ligament (known aspatellomeniscal or patellotibial band)

Superficial layer

Mixed with vastus medialis & lateralis muscle &distal continue to posterior femoral condyle

(patellofemoral ligament)



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Synovial lining

The intricacy of fibrous layercapsule is surpassed by itssynovial lining except posteriorly.

Synovium adheres to anterioraspect & side to the ACL & PCL.

Embryologically, the synoviallining of the knee joint capsule is

divided by septa into 3 separatecompartment

Superior patellofemoral compartment

2 separate medial & lateraltibiofemoral compartment



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Ligament of knee joint

Collateral ligament

Medial collateral ligament (MCL)

Lateral collateral ligament (LCL)

Cruciate ligament Anterior cruciate ligament (ACL)

Posterior cruciate ligament (PCL)

Posterior capsular ligament

Meniscofemoral ligament

Iliotibial band



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MCL

Attachment

Originmedial aspect of medial femoralcondyle

Insertionproximal tibia Function

Resist valgus stress force (specially inextended knee)

Check lateral rotation of tibia Also restrain anterior displacement of tibia

when ACL is absent.

MCL



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LCL

Attachment

Originlateral femoralcondyle

Insertionposteriorly to head

of fibula

Function

Resist varus stress force acrossthe knee

Check combined lateralrotation with posteriordisplacement of tibia inconjunction with tendon of

popliteal muscle.



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Cruciate ligament

Cruciate= Resembling a cross inLatin.

Located within the joint capsule &

are therefore calledIntracapsularLigaments.

Cruciate ligament provide stability insagittal plane

The ACL & PCL are centrallylocated within the capsule but lieoutside the synovial cavity.

ACL

PCL



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ACL

Attachment

Originfrom anterior surface the tibia in the

intercondylar area just medial to medial meniscus.

It spans the knee laterally to PCL & runs in a superior& posterior direction

Insertionto posteriorly on lateral condyle of femur

ACL is divided into 2 bands

Antero-medial band (AMB)

Postero-lateral band (PLB)



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Function of acl

Primarily

Check femur from being displaced posteriorly on the tibia

Conversely, the tibia from being displaced anteriorly on femur.

It tightens during extension, preventing excessive

hyperextension of the knee.

ACL carried 87% of load when anterior translatoryforce was applied to tibia with extended knee.

Check tibial medial rotation by twisting around PCL

ACL injury is common when knee is in flexed & tibiarotated in either direction



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PCL

Attachment

Originfrom posterior tibia in intercondylar area

and runs in a superior and anterior direction on

medial side of ACL. Insertion - to anterior femur on the medial condyle

PCL is divided into 2 bands

Antero-medial band (AMB)

Postero-lateral band (PLB)



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Function of pcl

Primarily

Check femur from being displaced anteriorly on the tibiaor

Tibia from being displaced posteriorly on femur.

It tightens during flexion & is injured much lessfrequently than ACL.

PCL carry 93% of load when posterior translatoryforce was applied to tibia with extended knee.

PCL play a role in both restraining & producingrotation of the tibia.



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Summary of ACL & PCL attachments

ACLRuns from anterior tibia to posterior femur

PCLRuns from posterior tibia to anterior femur



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Posterior capsular ligament

Oblique popliteal ligament

Posterior oblique ligament

Arcuate ligament:

Arcuate ligament lateral branch

Arcuate ligament medial branch



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Oblique popliteal ligament

Attachment

OriginThe central part of posterior aspect of

the joint capsule

Insertion - Posterior medial tibial condyle

Function

Reinforces posteromedial knee joint capsule

obliquely on a lateral-to-medial diagonal from

proximal to distal



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Attachment

OriginNear the proximal origin of the MCL

and adductor tubercle

InsertionPosteromedial tibia, posterior capsule& posteromedial aspect of the medial meniscus

Function

Reinforces the posteromedial knee joint capsule

obliquely on a medial-to-lateral diagonal from

proximal to distal



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Arcuate LigamentLateral Branch Medial branch

Distal

Attachment From posterior aspect of the head of the fibula

Proximal

Attachment

To tendon of popliteus

muscle & posterior capsule

Into oblique popliteal lig on

medial side of joint

FunctionReinforces the postero-lateral knee joint capsule

obliquely on a medial to lateral from proximal to distal


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Meniscofemoral ligament (MFl)

There are 2 portions of

MFL, at least one in 91%

of knees & 30% knee

having both. MFL are not true

ligaments because they

attach bone to meniscus,

rather than bone to bone.



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Meniscofemoral ligament (MFl)

Attachment OriginBoth originate from posterior horn of lateral

meniscus

Insertionto lateral aspect of medial femoral condyle

The LigamentofHumphry or Antero-MFL is the

ligament run anterior to PCL on tibia

The Ligament of Wrisberg orPostero-MFL is the

ligament run posterior to PCL, also known as3rdCruciate

Ligament of Robert

Function

They may assist PCL in restraining posterior tibial translation

Also assist popliteus muscle by checking tibial lateral rotation13 August 2013 Dr. Ratankhuman M.P.T., (Ortho & Sports) 40


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Bursa associated with knee

Pre-patellar bursa

Located between the skin & anterior surface of patella

They allows free movement of skin over patella duringknee flexion & extension

Subcutaneous bursa

Located between patellar ligament & overlying skin

Deep infra-patellar bursa

Located between patellar ligament & tibial tuberosity

Helps in reducing friction between the patellarligament & tibial tuberosity



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Function of knee joint

Osteokinemetic of knee joint

Primary motions

Flexion / Extension

Medial / Lateral Rotation

Secondary motions

Antero-posterior displacement of femur or tibia

Abduction / Adduction through valgus or varus force



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Flexion & extension

Axisno fixed axis but move through ROM

(frontal axis)

Plansagittal plan

ROM of flexion / extension

Flexion13001400

Extension50100 (Consider normal, beyond

this termed as Genurecurvatum) In close kinematic chain (OKC)flexion /

extension range is limited by ankle range.



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Medial / lateral rotation

AxisLongitudinal / Vertical axis

PlanTransvers plan

ROM at 900 knee flexion

Lateral rotation00400

Medial rotation00300



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TF CKC Flexion

Early 00 - 250 knee flexion

Posterior rollingof femoral

condyles on the tibia

As flexion continues Posterior Rollingaccompanied by

simultaneousAnterior glide of femur

Create a pure Spin of femur on the

posterior tibia



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TF CKC extension

Extension from flexion is areversal of flexion motion.

Early extension

Anterior rollingof femoralcondyles on tibial plateau

As extension continues

Anterior Rollingaccompanied by

simultaneousPosterior glide offemur

Produce a pure Spin of femoralcondyles on tibial plateau



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Tf ock flexion / extension

When tibia is flexed on a fixed femur

The tibia performedBoth Posterior Rolling &

Glidingon relatively fixed femoral condyles.

When tibia is Extended on a fixed femur

The tibia performedBoth Anterior Rolling &

Glidingon relatively fixed femoral condyles.



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13 August 2013 49Dr. Ratankhuman M.P.T., (Ortho & Sports)


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Locking of knee joint

CKC femoral extension from 300 flexion Larger medial femoral condyle continue rolling & gliding

posteriorly when smaller lateral side stopped.

These result in medial rotation of femur on tibia, seen in last

50

of extension. The medial rotation of femur at final stage of extension is

not voluntary or produce by muscular force, which isreferred as Automatic orTerminal Rotation.

The rotation within the joint bring the joint into a closed

packed or Locked position.

The consequences of automatic rotation is also known asLocking MechanismorScrew Home Mechanism.

OKClateral rotation of tibia on fixed femur



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Unlocking of knee joint

To initiate flexion, knee must be unlocked.

A flexion force will automatically result in lateral

rotation of femur

Because the larger medial condyle will move beforethe shorter lateral condyle.

Popliteus is the primary muscle to unlocked the knee.



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TF CKC Flexion: ACL Control

At full extension

Angle of ACL

inclination greatest

Anterior directedcomponent force will

eventuallyRestrain

Posterior Femoral Roll




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cont

As TF flexion increases

Angle of ACL inclination

decreases

Anterior directedcomponent force increases

sufficient enough to

produceAnterior Femoral

Slide


Hyperextension Impact on


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Hyperextension Impact onACL

End ROM extension

brings the mid-

substance of the ACL in

contact with the femoralintercondylar shelf

(notch of Grant)

This contact point actsas a fulcrum to tension

load the ACL


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TF CKC Flexion: PCL Control

Angle Of PCL Inclination

is greatest at full flexion.

Anterior directed

component force willeventuallyRestrain

Posterior Femoral Roll



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TF CKC Extension: PCL Control

As TF extension increases

Angle Of PCL Inclination

decreases

Posterior directed componentforce increases sufficient enough

toProduce Posterior Femoral

Slide


TF OKC Extension Arthrokinematics


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TF OKC Extension Arthrokinematics

sagittal plan

Extension

Meniscal migrate Anteriorly

Because of meniso-patellarligament


Menisco-patellarLigaments

TF OKC flexion Arthrokinematics


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TF OKC flexion Arthrokinematics

sagittal plan

FlexionMenisci migrate posteriorly because of

Semimembranosis attachment to medial meniscus

Popliteus attachment to lateral meniscus



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Knee axial rotation


Axial rotation of knee


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Axial rotation of knee

arthrokinemetic

Axisvertical axis

Plantransvers plan

ROMMaximum range is

available at 90 of knee flexion.

The magnitude rotation diminishes

as the knee approaches both full

extension and full flexion.

Medial condyle acts as pivot point

while the lateral condyles move

through a greater arc of motion,

regardless of direction of rotation.



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rotation of tibia

During Tibial lateral rotation on the femur Medial tibial condyle moves slightly anteriorly on

the relatively fixed medial femoral condyle, whereas

lateral tibial condyle moves a larger distance

posteriorly.

During tibial medial rotation

Medial tibial condyle moves only slightly

posteriorly, whereas the lateral condyle movesanteriorly through a larger arc of motion.



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During both medial and lateral rotation

The menisci reduce friction & distribute femoral

condyle force created on the tibial condyle

without restricting the motion. Meniscus also maintain the relationship of tibia

& femoral condyles just as they did in flexion

and extension.


Valgus (Abduction)/Varus


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Valgus (Abduction)/Varus

(Adduction)

AxisAntero-posterior axis

PlanFrontal plane

ROM

8 at full extension

13 with 20 of knee flexion.

Excessive frontal plane motion could

indicate ligamentous insufficiency



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pFj function

It work primarily as an anatomical pulley

It reduce friction between quadriceps tendon

& femoral condyle.

The ability of patella to perform its functionwithout restricting knee motion depends on

its mobility.



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PFJ articulating surface

The triangular shape patella is a largest sesamoidbone in body is a least congruent joint too.

Posterior surface is divided by a vertical ridge intomedial & lateral patellar facets.

The ridge is located slightly towards the medialfacet making smaller medial facet

The medial & lateral facet are flat & slightly

convex side to side & top to bottom. At least 30% of patella have 2nd ridge separating

medial facet from the extreme medial edge knownas Odd Facet of Patella.



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Femoral articulating surface

Patella articulate in femurwith intercondylar grooveor femoral sulcus onanterior surface of distalfemur.

Femoral surface areconcave side to side &

convex top to bottom butlateral facet is more convexthen medial surface.



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PFJ congruence

The vertical position of patella in femoral sulcus

is related to length of patellar tendon,

approximately 1:1 is (referred to as Insall-Salvati

index) An excessive long tendon produce an abnormally

high position of patella on femoral sulcus known

as patella alta.

In neutral or extended knee, the patella has little

or no contact with the femoral sulcus beneath.



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At 100200 of flexioncontact with

inferior margin of medial & lateral

facet. By 900 of flexionall portion of

patella contact with femur except the

odd facet.

Beyond 900 of flexionmedial

condyle inter the intercondylar notch

& odd facet achieves contact for the

first time. At 1350 of flexioncontact is on

lateral & odd facet with medial facet

completely out of contact.13 August 2013 Dr. Ratankhuman M.P.T., (Ortho & Sports) 70


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Medial-lateral PFJ stability

PFJ is under permanent control of 2 restraining

mechanism across each other at right angel.

Transvers group of stabilizer

Longitudinal group of stabilizer



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Transvers stabilizer

Medial & lateral retinaculum

Vastus Medialis & Lateralis

The lateral PF ligament contributes 53% of totalforce when in full extension of knee.



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Longitudinal stabilization

Patellar tendoninferiorly

Quadriceps tendonsuperiorly


Medial-lateral positioning of


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Medial lateral positioning of

patella / patellar tracking

When the knee is fully extended & relax, thepatella should be able to passively displacedmedially or laterally not more then one half ofpatella.

Imbalance in passive tension or change in lineof pull of dynamic structures will substantiallyinfluence the patella.

Abnormal force may influence the excursion ofpatella even in its more secure location withinintercondylar notch in flexion.


Medial & lateral force on


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Medial & lateral force on

patella

Since the action line of quadriceps & patellar

ligament do not co-inside, patella tend to pulled

slightly laterally & increase compression on

lateral patellar facets. Larger force on patella may cause it to

subluxation or dislocate off the lateral lip of

femur.

Genu valgum increase the obliquity of femur &

oblique the pull of quadriceps.



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Femoral anteversion & tibial torsion creates anincreased obliquity in patella predisposing toexcessive lateral pressure or to subluxation ordislocation.

Excessive tension in lateral retinaculum (orweakness of VMO) may cause the patella to tiltlaterally.

Insufficient height of lateral lips of femoral

sulcus may create patellar subluxation or fullydislocation, even with relatively small lateralforce.



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Muscles of knee

&its function



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Muscles of the Knee

Area One-joint Muscle Two-joint Muscle

Anterior

Vastus Lateralis

Rectus Femorisvastus Medialis

Vastus Intermedialis

PosteriorBiceps Femoris

(Short)

Biceps Femoris (Long)Semimembranosus

Semitendinosus

Sartorius

GracilisGastrocnemius

Lateral Tensor Fascia Latae


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Muscles of Posterior Knee

Knee FlexorsSemimembranosus, Semitendinosus, BicepsFemoris (Long & Short Heads), Sartorius,

Gracilis, Popliteus & Gastrocnemius Muscles

Flex + Tibial

Medial Rotators

Popliteus, Gracilis, Sartorius, Semimembranosus

& Semitendinosus Muscles

Flex + Tibial

Lateral RotatorBiceps Femoris

Flex +

Abductor

Biceps Femoris, Lateral Head Gastrocnemius &

Popliteus

Flex +

Adductor

Semimembranosus, Semitendinosus, Medial Head

Gastrocnemius, Sartorius & Gracilis

p


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Knee flexor groups


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Knee flexor groups

7 muscles flex the knee [Semimembranosus,Semitendinosus, Biceps Femoris (Long & ShortHeads), Sartorius, Gracilis, Popliteus &Gastrocnemius Muscles].

5 muscles of flexors (Popliteus, Gracilis,Sartorius, Semimembranosus & SemitendinosusMuscles)

They have the potential to medially rotate the tibia ona fixed femur

Whereas the biceps femoris is capable of rotating thetibia laterally.


Knee flexor groups cont


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Knee flexor groups cont

The lateral muscles (Biceps Femoris,

Lateral Head of Gastrocnemius, &

Popliteus)

Capable of producing valgus moments at knee The medial muscles (Semimembranosus,

Semitendinosus, Medial Head of

Gastrocnemius, Sartorius & Gracilis)

Can generate varus moments


biceps femoris or Lateral


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c s or s or r

Hamstring

Proximal attachments: By two heads: Long headto the tuberosity of ischium,

having a common tendon of attachmentwith semitendinosus.

Short headto the lower portion of shaft of

femur & to lateral intermuscular septum. Distal attachments:

2 heads unite to be attached to the head offibula, to the lateral condyle of the tibia &to the fascia of leg.

AXN: Hip extension & external rotation

Knee flexion & external rotation.


Semitendinosus or medial


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hamstring

Proximal attachment:

Tuberosity of ischium, having a

common tendon with the long

head of the biceps.

Distal attachment:

Medial aspect of tibia near the

knee joint, distal to the attachment

of the gracilis.

AXN:

Hip extension and internal rotation

Knee flexion and internal rotation.


semimembranosus


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semimembranosus

Proximal attachment:

Tuberosity of the ischium

Distal attachment:

Medial condyle of the tibia.

AXN:

Knee flexion and internal rotation

Hip extension and internal rotation.


Gastrocnemius


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Gastrocnemius

Proximal attachments:

Above the femoral condyles and span the knee joint

on the flexor side.

The muscular portion of the gastrocnemius may beseen contracting in resisted flexion of the knee.

Because the gastrocnemius is more important as a

plantar flexor of the ankle than as a knee flexor

Distal attachments: To the posterior calcaneus


Popliteus


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Popliteus

Proximal attachment: By a strong tendon from the lateral condyle of

the femur.

The muscle fibers take a downward medialcourse and are attached into proximal posterior

portion of body of tibia. Distal attachment:

widespread in a proximal-distal direction,giving the muscle a somewhat triangularshape.

AXN: Medial rotation and flexion of knee.


Muscle passing medial knee


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Muscle passing medial knee


Anterior Muscles


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Anterior Muscles

Quadriceps musclescomprise 4 muscles that

cross the anterior knee

Rectus femoris Vastus lateralis

Vastus Intermedialis

Vastus Medialis


Quadriceps muscle


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Quadriceps muscle

Functions Together, the 4 components of quadriceps femoris muscle

function to extend the knee.

Rectus femorisbeing a 2 joint muscle, it also involved in hipflexion along with knee extension.

Angle of pull of Quadriceps Vastus lateralisPull 350 Lateralto long axis of femur

Vastus IntermediusPullParallel to Shaftof femur, makingpurest knee extensor.

Vastus MedialisPull depended on segment of muscle Upper fibers Vastus Medialis Longus (VML) angled 150180 Medially

Distal fibers Vastus Medialis Oblique (VMO) angled 500550 Medially



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Patellar Influence on


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Quadriceps Function

Patella lengthens the MA of quadriceps byincreasing the distance of quadriceps tendon &

patellar tendon from the axis of the knee joint.

The patella, as an anatomic pulley, deflects theaction line of quadriceps away from the joint centre,

increasing the angle of pull & enhancing extension

torque generation.

Pull of quadriceps also creates anterior translationof tibia on femur increasing ACL restraint



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Quadriceps activities


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During weight-bearing

When an erect posture is attained Minimal activity of quadriceps because the LOG

passes just anterior to knee axis results in agravitational extension torque that maintains the joint

in extension. In weight-bearing with the knee slightly flexed

The LOG pass posterior to knee joint axis

As the gravitational torque tend to promote kneeflexion, the activity of quadriceps is necessary tocounterbalance the gravitational torque and maintainthe knee joint in equilibrium.


LOG & Movement arm (MA)


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during squatting


Quadriceps activities during


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nonweight-bearing

TheMA of resistance is minimalwhen the kneeis flexed to 900 but increases as knee extension

progresses.

Therefore, greater quadriceps force is requiredas the knee approaches full extension.

The opposite happens during weight-bearing

activities.


LOG & Movement arm (MA)


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during non-weight bearing


Quadriceps Strengthening:

Weight-Bearing versus NonWeight-


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Weight-Bearing versus NonWeight-

Bearing

Weight-bearing quadriceps exercises as squat

& leg press resulted in a posterior shear force

at knee throughout the entire ROM

There wasNo Anterior Shearanywhere inthe ROM.

In contrast, anterior shear force in a non

weight bearing knee extension exercisemaximal anterior shear occurring between

200 and 100.


Quadriceps Strengthening:

Weight-Bearing versus Non


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Weight-Bearing versus Non

Weight-Bearing cont

APosterior Shear Force was also foundduring NonWeight-Bearing Exercise, only

between 600 and 1010 of flexion.

Weight Bearing Exercises are oftenprescribed afterACL or PCL injurybecause

of less stressful, more like functional

movements & safer than nonweight-bearingexercises.


Other muscles helping


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knee extension

The actions of the Gluteus Maximus& Soleus Muscles can influence

knee motion in weight-bearing.

Although they do not cross the kneejoint, these muscles are capable of

assisting with knee extension.


Iliotibial Band or IT tract


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Iliotibial Band or IT tract

Proximally

The IT band is from TensorFascia Lata (TFL), GluteusMaximus & Gluteus Mediusmuscles.

Distally Attach to lateral intermuscular

septum & inserts into theAnterolateral Tibia (GerdysTubercle).

IT band also attaches topatella via lateral PF ligamentof lateral retinaculum.


ITB

GM

TFL


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AXN:

Reinforcing anterolateral aspect of knee joint

Assisting ACL in checking posterior femoral or

anterior tibial translation when the knee joint is nearly

full extension.

With the knee in flexion, the combination of IT band,

LCL & popliteal tendon increases the stability of

lateral knee.


AXN line for itb


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AXN line for itb

In extended knee IT band moves anterior to the knee joint axis.

In flexed knee

IT band moves posteriorly over the lateral femoralcondyle as the knee is flexed.

The IT band, therefore, remains consistently

taut, regardless of hip or kneesposition.



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Stabilization of knee joint


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Stabilization of knee joint

Classification of supporting structure of knee Functional

Static stabilizer

Dynamic stabilizer

Structural

Capsular method

Extra-capsular method

Location Medial joint compartment

Lateral joint compartment


Static stabilizer


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Static stabilizer

It include the passive structures, such as Capsule

Ligaments

Meniscopatellar lig, PF lig,

MCL & LCL,

ACL & PCL,

Oblique poplitial &

Transverse lig.


Dynamic stabilizer


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Dynamic stabilizer

It includes following muscles & oponeuroses Quadriceps femoris,

IT band,

Extensor retinaculum, Poplitius,

Pes anserinus,

Hamstrings and also

Gastrocnemius


Medial joint stabilizers


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Medial joint stabilizers

Structure includes Medial patellar retinaculum,

MCL,

Oblique poplitial ligament & PCL


Lateral joint stabilizers


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Lateral joint stabilizers

The structure included in static & dynamicstabilization of knee

IT band,

Biceps femoris, Popliteus,

LCL,

Meniscofemoral arcuate,

ACL &

Lateral patellar retinaculum



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Knee Joint StabilizersDi ti St t F ti


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Direction Structures Functions

Varus/valgus

stabilizers

Medial collateral ligament

Anterior cruciate ligament Posterior cruciate ligament

Arcuate ligament


Sartorius muscle

Gracilis muscle

Semitendinosus muscle Semimembranosus muscle

Medial head of gastrocnemius muscle

Limits valgus of tibia

Lateral collateral ligament

Iliotibial band

Anterior cruciate ligament

Posterior cruciate ligament

Arcuate ligament


Biceps femoris muscle

Lateral head of gastrocnemius muscle

Limit Varus of tibia

Knee Joint Stabilizers


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Direction Structures Functions

Internal/external

rotational stabilizers

Anterior cruciate ligament

Posterior cruciate ligament

Posteromedial capsule

Meniscofemoral ligament

Biceps femoris

Limit medial rotation of

tibia

Posterolateral capsule

Medial collateral ligament

Lateral collateral ligament

Popliteus muscle

Sartorius muscle Gracilis muscle Semitendinosus

muscle

Semimembranosus muscle

Limit lateral rotation of

tibia

References


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References

Joint Structure and Function: A ComprehensiveAnalysis,Fourth Edition, Cynthia C. Norkin, 2005

Joint Structure and Function: A Comprehensive

Analysis, Third Edition, Cynthia C. Norkin

Clinical Kinesiology andAnatomy,Fourth Edition,

Lynn S. Lippert, 2006

Basic Biomechanics of the Musculoskeletal

System, third edition, Margareta Nordin

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