Knee Flashcards
What is the screw home mechanism and what muscle locks it into place?
Rotation between the tibia and femur that occurs between full extension and 20 degrees flexion
Once fully extended and rotated the knee is locked into place by the Popliteus
What structures does the MCL blend and what movements does it protect against?
Blends with the semimembranosus and medial meniscus.
Provides stability against valgus stress and external rotation
What structures does the LCL function with? What is the distal attachment of the LCL?
ITB, Popliteus, arcuate ligament complex and biceps tendon
-Distal attachment is the fibular head
ACL (4) -Prevents? stability in which ROM? how is it injured? tight vs loose?
- Prevents anterior translation of tib and hyper extension
- provides stabilization in extension
- injured during planted internal rotation with valgus force
- Tight in extension and loose during flexion
ACL (4) -Prevents? stability in which ROM? how is it injured? tight vs loose?
- Prevents anterior translation of tib and hyper extension
- provides stabilization in extension
- injured during planted internal rotation with valgus force
- Tight in extension and loose during flexion
PCL (3) - Tight vs Loose? Prevents? Reinforces?
Taught in full ROM, Prevents excessive internal rotation and posterior translation of tib on femur, reinforces the posteromedial joint capsule
What is Patella Baja and Patella Alta?
Baja is if the patella is sitting too low (almost right over the joint line)
Alta is if the patella is sitting too high (almost right over the supracondylar ridges)
What does it mean if you have Squinting vs frog eyed patellas?
These terms are in reference to where your patellas are sitting compared to normal.
Squinting means they sit more medially, indicating tightness of medial structures of the knee
Frog eyed means they sit more laterally, indicating tightness of lateral structures of the knee
What does it mean if you have Squinting vs frog eyed patellas?
These terms are in reference to where your patellas are sitting compared to normal.
Squinting means they sit more medially, indicating tightness of medial structures of the knee
Frog eyed means they sit more laterally, indicating tightness of lateral structures of the knee
What is the Q angle? What is a normal range? What could happen if one is above or below this range?
Q angle is measured by drawing a line between ASIS and the Patella and then a line between the center of the patella and the tibial tubercle then measuring the angle between the two lines, this indicates the angle of pull on the quads.
Normal range is 13-18 degrees
Below 13 degrees will indicate patella alta
Above 18 degrees will indicate femoral anteversion
What is the Q angle? What is a normal range? What could happen if one is above or below this range?
Q angle is measured by drawing a line between ASIS and the Patella and then a line between the center of the patella and the tibial tubercle then measuring the angle between the two lines, this indicates the angle of pull on the quads.
Normal range is 13-18 degrees
Below 13 degrees will indicate patella alta
Above 18 degrees will indicate femoral anteversion
Muscles of the knee which cause flexion
BF, Semimembranosus and tendinosus, gracilis, sartorius, gastroc, popliteus, plantaris
Muscles causing external rotation
BF
Muscles causing internal rotation
Popliteus, semimem, semiten, sartorius and gracilis
Knee “Gives way” or locks
meniscus
