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York University
Kinesiology & Health Science
KINE 3575
Gus Kandilas

The Knee Introduction: - Females are more prone to knee injuries o Wider Q angle (15° instead of the 8-10° seen in males)  20°+ is excessive – can lead to conditions associated with improper patellar tracking in femoral groove  Lines drawn from ASIS to the centre of patella AND tibial tubercle to the centre of patella  Measured at full extension and flexion at 30° o Weaker muscles o Patellar tracking problems o Hormonal effects on ligaments - BUT males have a higher risk of knee injury – more involved in contact sports - “Genu” makes reference to the knee - “Valgus” and “varus”: o Denote an anatomical predisposition  Genu valgum – knock kneed  Genu varum – bow legged  Genu hypercurvatum – hyperextension (more common in females) o Describe a force to the knee  Valgus force – outside in, most commonly seen in sports  Varus force – inside out - 2 articulations at the knee: o Patellofemoral joint (non-weight baring) o Tibiofemoral joint (weight baring) - Relies heavily on ligamentous support - Stresses causing knee injury: o Compression (contusion) o Tension (muscle tendon tears) o Shear (ligament sprains) o Patella-femoral tracking = compression + tension Range of Motion - Extension: bone-to-bone end feel o Fully extended = 0° o Vastus medialis obliques responsible for the last 15°-20° of extension  “Quad’s leg” – can’t completely straighten the leg - Flexion: soft tissue approximation end feel - Medial and lateral rotation Bones - Femur – lateral condyle > medial condyle to prevent knee cap from dislocating o Condyles form a trochlea (anterior groove) to receive the patella - Tibia – weight baring, lateral and medial menisci are located above o Has two shallow concavities that articulate with their respective femoral condyles – divided by the popliteal notch o Tibial tubercle apophysis – where patellar tendon attaches  Can be the sight of Osgoode Schlotters or patellar tendonitis - Fibula – not weight baring - Patella – largest sesamoid bone in the body o Five bony ridges on the back keep the knee cap tracking normally o Located in the tendon of the quadriceps femoris muscle Menisci: - Two semilunar fibrocartilages - For shock absorption, to deepen the articular surface of/stabilize the knee - Transverse ligaments join the anterior portions of the medial and lateral menisci - Move anteriorly during extension and posteriorly during flexion o Because of tendon attachment (no movement = tear) - Painful to tear even though there is not nerve supply here o Pain/inflammation to surrounding structures - Only outer third of menisci have blood supply – supplied by middle genicular artery o No blood supply to inner 2 thirds – can’t heal – remove damaged portions  Can’t remove all – bone-on-bone = osteoarthritis - Lateral menisci – “O” shaped, no ligament attachment, more movement here - Medial menisci – “C” shaped, lot of stress here, more injuries o Deep fibres of MCL attach here  Tear MCL = damaged medial meniscus o Stabilize the knee when leg is bent to 90° o Attached to tibia and joint capsule by the coronary ligaments o Palpable when tibia is internally rotated, retracts when externally rotated Ligaments: - Controls stability of the knee - Knee most unstable in the medial direction, then lateral and anterior directions - Collaterals: o Medial Collateral Ligament – flat, superficial and deep fibres, on side of knee to protect against valgus forces  From medial epicondyle of femur to tibia o Lateral Collateral Ligament – round, on side of knee to protect against varus forces  From lateral epicondyle on femur to head of fibula  Can be palpated – sit half cross legged, pull ankle up - Cruciates: cross each other within the knee for stability o Anterior Cruciate Ligament – prevents anterior displacement of knee cap  Prevents femur from moving posteriorly and tibia from moving anteriorly  Attaches in front of the tibia, passes backward to attach laterally to the inner surface of the lateral condyle of the femur  Consists of 3 bands:  Anteromedial – tightens in flexion  Intermediate  Posterolateral – tightens in extension  Torn = “pop” + immediate swelling  Females more prone to ACL tears o Posterior Cruciate Ligament – prevents posterior displacement of knee cap (hyperextension)  Prevents femur from moving anteriorly and tibia from moving posteriorly  Attaches to the anterior portion of the lateral surface of the medial condyle of the femur  2x larger/stronger than ACL  Mechanisms of injury:  Hyperextension of the knee  Falling on the tibia with the knee flexed to 90° Bursa: - Prepatellar bursa – housemaids’ knee – from constantly being on the top of your knees - Superficial infrapatellar bursa – clergy man’s knee – from prolonged kneeling o Lays on top of the deep infrapatellar bursa and fat pad - Anserine bursa – deep to pes anserinus “goose’s foot” (tendons of graciliss, sartorius, and semitendinosus muscles) – medial side of the knee - Baker’s cyst – when group of bursa at back of knee become inflamed Musculature: - Quadriceps – knee extensors o Rectus femoris – attaches at anterior superior iliac spine (AIIS), inserts on tibial tuberosity to form patellar tendon  Also flexes the hip (because it attaches here) o Vastus lateralis, vastus medialis, vastus intermedialis – attach at femur (lateral, medial, anterior aspects respectively), insert on tibial tuberosity to form patellar tendon - Hamstrings – knee flexors, innervated by various branches of the sciatic nerve o Biceps femoris – long head attaches on ischial tuberosity, short head on posterior, lateral side of femur (linea aspera), inserts on fibular head  Also externally rotates o Semitendinosus, semimembranosus – attach on ischial tuberosity, insert on medial side of tibia  Also internally rotates - Gastroc-soleus complex – knee flexion - Popliteus – knee flexion, internal rotation of tibia on femur in non-weight bearing, external rotation of femur on tibia in weight bearing o Behind the knee o Prevents anterior displacement of the knee o Tested using Taking Off the Shoe Test  Positive = tenderness at point of attachment of popliteus (just above lateral condyle of femur) Injuries of the Knee - Meniscal Injury: o Mechanism of injury:  Degenerative changes with age nd  Ligamentous disruption (ex: 2 degree MCL tear)  Stress put on menisci because of previous ligament damage  Isolated or repetitive rotational stresses  Foot planted, leg rotates (worse in cleats)  Abnormal meniscal shape or attachment o Will hear a “crunch” with a meniscal tear  Little s
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