Knee Anatomy/Biomech Flashcards
(35 cards)
Where is the tibiofemoral joint axis?
Lateral Epicondyle
ROM requirement for gait
60-70
ROM requirement for stairs
70-110
ROM requirement for sitting
90-110
Normal frontal plane angle
6-10 valgus
Excess valgus angle
> 10
Excess varus angle
<5
Screw Home Mechanism (open chain) locking
Tib ER
Screw Home Mechanism (open chain) unlocking
Quads eccentrically contract
Screw Home Mechanism (closed chain) locking
Femoral IR (plus some hip ext)
Screw Home Mechanism (closed chain) unlocking
Popliteus contracts (which ERs femur)
Close-pack position
Full ext
Tibial ER
Open-pack position
Flex 20-30
Capsular pattern
- Flexion
- Extension
Contact area between patella & femur at first 20 flexion
Inferior patella
Anterior femoral condyles
Contact area between patella & femur at 45 flexion
Midpoint of patella
Midpoint of femur
Contact area between patella & femur at 90 flexion
Superior patella
Posterior femur
Contact area between patella & femur at maximum flexion
Med/Lat sides of patella
Posterior sides of femoral condyles
Odd facet
Doesn’t come into play until beyond 135 flex. At this point, odd facet is the only articulating surface
Open-chain: most stress on patellofemoral joint & ACL in ____
extension
Closed-chain: most stress on patellofemoral joint & ACL in ____
90 flexion
What are the 3 cartilage structures?
Bursa
Fat pads
Menisci
ACL: Anteromedial bundle tightest in ___
45 flexion
ACL: Posterolateral bundle tightest in ___
full extension
