THE KNEE JOINT

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THE KNEE JOINT

• ASHLEY BATES
• KAREN BOEVINGLOH
• KATIE DOTY
• KELLY HUTCHESON
• JENNY LAURENTIUS

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BONES WITHIN THE KNEE JOINT

• The joint between the femur and tibia is the
  principal articulation of the knee joint. 
  Another bone in the knee joint is the patella,
  the largest sesamoid bone in the body.       
• Grays 473http//www.wmt.com/TotalKnee/kneeImage
  s
• /knee-anatomy-callouts2.jpg

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MUSCLES ACTING ON THE KNEE JOINT

• Quadriceps Muscles and insertion
• Rectus Femoris-patella
• Vastus Lateralis-quadriceps tendon to patella
• Vastus Medialis-quadriceps tendon to patella
• Vastus Intermedius-quadriceps tendon to patella
• Hamstring Muscles and insertion
• Semimembranosus-medial condyle of tibia
• Semitendinosus-upper part, medial surface of
  tibia
• Biceps Femoris-head of fibula
• http//www.harkema.ucla.edu (pictures)

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• Insertions of Muscles
• Sartorius-upper medial surface
• of tibial shaft
• Gracilis-upper part of shaft of
• tibia on its medial surface
• Origins of Muscles
• Gastrocnemius-medial and
• lateral condyles of femur
• Plantaris-lateral supracondylar
• ridge of femur

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• Origins and Insertions of Muscles
• Popliteus-
• OPosterior surface of proximal tibia
• ILateral femoral condyle
• Articularis genu-
• OLower anterior surface of the femur
• IUpper part of the joint capsule
• http//www.rad.washington.edu/staticpix/atlas2/pop
  liteus001.jpg

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Femoral Nerve
INNERVATION OF THE KNEE JOINT

• Supplies Anterior Compartment of Thigh
• - Rectus Femoris
• - Vastus Lateralis
• - Vastus Medialis
• - Vastus Intermedius
• - Sartorius
• - Iliacus
• - Pectineus

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Obturator Nerve

• Supplies Medial Compartment of Thigh
• - Adductor Magnus (Anterior Fibers)
• - Adductor Longus
• - Adductor Brevis
• - Gracilis

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Gluteal Nerves

• Superior Gluteal Nerve Supplies
• - Tensor Fasciae Latae
• Inferior Gluteal Nerve Supplies
• - Gluteus Maximus

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Sciatic Nerve

• Tibial Portion Supplies
• - Adductor Magnus (Posterior Fibers)
• - Biceps Femoris (Long Head)
• - Semitendinosus
• - Semimembranosus
• Common Peroneal Portion Supplies
• - Biceps Femoris (Short Head)

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Arteries
BLOOD SUPPLY OF THE KNEE JOINT

• Popliteal Artery
• - Continuation of Femoral Artery
• Genicular Arteries
• - Superior Medial and Lateral
• - Inferior Medial and Lateral

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Ligaments of the Knee

• ACL
• PCL
• MCL
• LCL
• Patellar
• Medial Meniscus
• Lateral Meniscus

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Cruciate Ligaments

• The cruciate ligaments are very strong, situated
  in the middle of the joint nearer to its
  posterior surface.
• They are called cruciate because the cross each
  other similar to an X.

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Anterior Cruciate Ligament

• The ACL attaches to a posterio-lateral part of
  the femur and to an anterio-medial part of the
  tibia.
• It prevents the tibia from being pushed too far
  anterior relative to the femur.
• Tearing of the ACL is common among athletes.

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Posterior Cruciate Ligament

• The PCL connects the posterior intercondylar area
  of the tibia to the medial condyle of the femur.
• It resists forces pushing the tibia posteriorly
  relative to the femur.
• It is also stronger and shorter than the ACL.

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Medial Collateral Ligament

• The MCL resists forces pushing the knee medially
  which would otherwise produce Valgus deformity.

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MCL continued...

• The MCL is a broad and flat membranous band
  situated posterior on the medial side of the
  joint.
• It is attached to the medial condyle of the femur
  and to the medial condyle of the tibia.

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Lateral Collateral Ligament

• The LCL resists forces pushing the knee laterally.

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Patellar Ligament

• This ligament is the central portion of the
  common tendon of the quadriceps femoris.
• It is about 8cm long.

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Menisci

• They are two pads of cartilaginous tissue which
  serve to disperse friction between the tibia and
  the femur.
• They are shaped concave on the top and flat on
  the bottom.
• They are attached to small depressions between
  the condyles of the tibia and towards the center
  they are unattached and their shape narrows.

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Menisci Continued...

• The menisci disperse the weight of the body and
  reduce friction during movement.
• Since the femur and the tibia meet the menisci
  spread the bodys weight.
• There are two menisci
• Lateral Meniscus
• Medial Meniscus

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Movements of the Knee Joint

• The main movement of the knee joint is flexion
  and extension.

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During Flexion

• When the knee is bent and the foot is on the
  ground, some rotation of the distal end of the
  femur is possible on the upper end of the tibia.
  
• This voluntary rotation is possible because it is
  the only position in which the tibial collateral,
  fibular collateral, and cruciate ligaments of the
  joint are not tense.
• When the knee is flexed and the ligaments are
  loose, the knee would fall off the tibia if it
  werent for the cruciate ligaments.
• The posterior cruciate prevents the movement of
  the femur forward on the tibia and the anterior
  cruciate prevents the movement backward.

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During Extension

• The main extensor is the quadriceps femoris
  muscle.
• The muscle that locks the knee into full
  extension is the tensor fascia latae and gluteus
  maximus by way of the iliotibial tract.
• To break full extension and start flexion, the
  popliteus muscle is used. This muscle pulls on
  the lateral condyle of the femur causing it to
  laterally rotate.

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Muscles That Flex the Leg at the Knee Joint

• Hamstring Muscles Semimembranosus,
  Semitendinosus, Biceps Femoris
• Sartorius
• Gracilis
• Gastrocnemius

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Muscles That Extend the Leg at the Knee Joint

• Quadriceps Muscles Rectus Femoris, Vastus
  Lateralis, Vastus Medialis, Vastus Intermedius
• Gluteus Maximus
• Tensor Fascia Latae

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While Walking

• The knee is extended during the swing through
  phase and flexed during the push off phase.
• When the knee is extended during walking, the
  foot is laterally rotated.
• If the foot medially rotated, the person would
  trip over their own feet. It is then normal for
  lateral rotation of the tibia and foot.

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Knee InjuriesMedial Collateral Ligament (MCL)
Injury

• common in contact sports, as well as those
  involving significant twisting. Isolated tears
  due to external rotation of the foot, and a
  valgus torque are common.
• frequently combined with anterior cruciate
  ligament rupture. Combined injuries may in turn
  be associated with tears to the medial meniscus
• http//www.owlnet.rice.edu/kine351/knee.pdf

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Knee InjuriesAnterior Cruciate Ligament (ACL)
Injury

• Fairly common in a wide range of sports injuries
  can be either contact or non-contact
• Non-contact ACL injuries typically occur when
  decelerating, landing after a jump, twisting, or
  cutting activities .
• Contact injuries usually result from a valgus
  force to a planted foot.
• Incidence of ACL injuries is much more common in
  females than males
• http//www.owlnet.rice.edu/kine351/knee.pdf

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Knee InjuriesACL Injury

• The ACL can be torn when the tibia is stressed
  suddenly in relation to the femur.
• Here you can see two types of contact injury
• In the first the knee is forcibly hyper-extended,
  and in the second the knee is forcibly
  hyper-flexed
• http//www.kneeguru.co.uk/html/steps/step_02_cruci
  ates/injury.html

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Knee InjuriesACL Injury

• Much more frequently, however, the ligament is
  injured without contact with another player, eg
  running and cutting to the same side, landing on
  one foot while the body is still twisting
  (non-contact injury), or in situations where -
• the body is forward flexed
• the hip is abducted ('legs apart')
• the knee is internally or externally rotated with
  valgus ('stressed from the outer side')
• the foot is pronated ('rolled over')
• http//www.kneeguru.co.uk/html/steps/step_02_cruci
  ates/injury.html

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Knee InjuriesMeniscus Tears

• Quite common among athletes
• Common mechanism of injury for meniscal tears is
  a twisting force on a weight bearing flexed knee
• Meniscal tears may be traumatic or degenerative
  with a mild injury producing the problem
• Medial meniscus has a firm attachment to the deep
  fibers of the medial collateral ligament,
  therefore any injury to the MCL, can also lead to
  a meniscal injury
• http//www.owlnet.rice.edu/kine351/knee.pdf

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Knee InjuriesPatellar SubluxationPatellofemoral
joint instability

• Recurrent subluxation and dislocation of the
  patella is usually the result of a minor injury
  superimposed upon some mechanical underlying
  abnormality
• Recurrent dislocation of the patella is more
  common in girls, perhaps because of greater
  ligamentous laxity
• Patellar dislocation of any type is rare in the
  normal knee. The underlying knee abnormality
  predisposing to this condition may be either soft
  tissue or bony abnormality.
• http//www.owlnet.rice.edu/kine351/knee.pdf

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Knee InjuriesPatellar tendinitis

• Commonly seen in athletes participating in
  jumping sports such as volleyball, basketball,
  dance, and gymnastics. It is often referred to as
  jumpers knee
• Jumping produces excessive stress on the extensor
  apparatus of the knee especially at the site of
  tendon attachment to bone. The injury most
  commonly occurs at the lower pole of the patella,
  though it can also occur at the superior pole of
  the patella, and at the insertion into the tibial
  tubercle
• Patellar tendinitis is an overload injury, is
  more common in men, and often results from poor
  training methods
• Pathological features within the tendon include
  inflammatory change, cyst formation, and partial
  tearing
• http//www.owlnet.rice.edu/kine351/knee.pdf

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Knee InjuriesOveruse Knee Injury

• Also called Micro-trauma
• Includes tendonitis of the knee, knee bursitis,
  muscle strains, iliotibial band syndrome (ITBS),
  runners knee
• Due to overstress of normal tissue instead of
  damage from one event, the knee suffers many
  repetitive injuries over a period of time
• Micro-trauma often occurs with a sudden increase
  in exercise level, such as when a runner
  increases distance or a tennis player plays extra
  sets
• Treatment Rest, Ice, Compression, Elevation
  (RICE)
• http//www.apta.org/AM/Template.cfm?SectionHomeC
  ONTENTID24738TEMPLATE/CM/HTMLDisplay.cfm