Ch. 9 Knee Joint Flashcards
Largest diathrodial joint in body?
Knee joint
Between fibula and tibia, which bears most of the weight?
Tibia (medial bone)
Which bone in the knee area is not part of the knee joint?
Fibula (lateral)
Bone that is sesamamoid (floating), & is imbedded in quadriceps and patellar tendon
Patella
Largest bone in body
Femur
Bony landmarks in knee joint (TtMfcLfc)
• Tibial tuberosity
• Medial & lateral femoral
condyles
2 knee joints
Tibiofemoral joint (ginglymus)
Patellofemoral joint
What forms cushion between joints that is attached to tibia?
Menisci/meniscus
What enhances stability?
Mensisci/ meniscus
What forms receptacle for medial femoral condole and is the larger meniscus?
Medial meniscus
What meniscus receives lateral femoral condyle
Lateral meniscus
Supplies knee w/ synovial fluid & lies under patella and between surfaces of tibia and femur. Is considered the capsule of the knee
Synovial cavity
Posterior to patellar tendon
Infrapatellar fat pod
How many bursae are in & around the knee that absorbs shock/reduces friction
10
What is the ACL and PCL?
Anterior cruciate ligament (ACL) &
posterior cruciate ligament (PCL)
Which Cruciate ligament stabilizes femur?
ACL
Which Cruciate ligament stabilizes tibia?
PCL
What injury in the knee is more common in females?
ACL injury/tear
Causes of ACL Tear (Nrf: P,C,Lvp,H,Q
VqcTf)
noncontact rotary forces: planting, cutting, landing in a valgus position, hyperextension, or by violent quadriceps contraction which pulls tibia
forward on femur
PCL injuries
Direct contact on anterior tibia with an opponent or playing surface
What is the MCL & LCL
• Medial collateral ligament (MCL) (TIBIAL CL)
• Lateral collateral ligament (LCL)
(FIBULAR CL)
Which ligament is commonly injured in contact sports?
MCL
Alignment Variation: Bending backward/knee hyperextension
Recurvatum
Alignment Variation: Outward angulation of the distal segment of a bone or joint/knocked knees
Valgus
Alignment Variation: Inward angulation of the distal segment of a bone or joint/bowlegs
Varus
What is the anotomical position of knee extension (starting point)
0°, not uncommon to have hyperextension or 10°
Internal & external rotation occurs when knee is flexed at…
30° or greater
From flexion to extension, what is the term knee is said to extend
Knee “screws home” due to shape of femoral condyle
TF: No rotation of knee when in full extension
True
Bending or decreasing angle between femur & leg, characterized by heel moving
toward buttocks
Flexion
Straightening or increasing angle
between femur & leg
Extension
Rotary movement of leg laterally
away from midline
External rotation
Rotary movement of leg medially
toward midline
Internal rotation
3 nerve plexus in knee joint
-lumbosacral plexus
lumbar plexus
sacral plexus
Lumbar plexus goes to…
Femoral nerve
-quadriceps
Sacral plexus goes to…
Sciatic nerve
-tibial and fibular division
-hamstrings
Quadricep muscle group are primarily needed to…
Extend knee
Vital for jumping (acts as decelerator)
Quadriceps location
Anterior portion of thigh
4 quadricep muscles (RF,Vl,Vi,Vm)
-Rectus femoris
• Vastus lateralis
• Vastus intermedius
• Vastus medialis
Quad strength or power may be indicated by… (test)
Vertical jump
…&… are essential for maintenance or patellofemoral stability
Strength & endurance
Intersection of two imaginary lines at the patella/knee joint
Q angle
The two imaginary Q angle lines
• Central line of pull: ASIS to patella
• Line of pull of patella: patella to tibial tuberosity
Males have 15° or less Q angle, whereas females have 20° or less due to having a…
Wider pelvis
O&I Rectus femoris
• O: ilium
• I: patella
O&I Vastus lateralis
• O: femur
• I: patella
Largest quadriceps muscle
Vastus lateralis
O&I Vastus intermedium’s
• O: femur
• I: patella
Only quadriceps muscle that is not palpable
Vastus intermedius
Central quad muscle
Rectus femoris
O&I Vastus Medialis
• O: femur
• I: patella
Hamstring muscles are primarily responsible for…
Knee flexion
Location or hamstring
Posterior portion of thigh
TF: Hamstring muscles are ANTAgonists to quadriceps at knee
True
3 hamstring muscles
• Semimembranosus
• Semitendinosus
• Biceps femoris
O&I Semimembranosus muscle and is under…
• O: ischium
• I: tibia
• Under semitendinosus
O&I Semitendionsus muscle that is on top of…
• O: ischium
• I: tibia
• “On top” of
semimembranosus
O&I Biceps femoris
• O: ischium, femur
• I: tibia, fibula
Most superficial of the hamstrings
Biceps femoris
O&I Popliteus muscle
• O: femur
• I: tibia
Agonists: Knee extension
• Rectus femoris
• Vastus lateralis
• Vastus intermedius
• Vastus medialis
Agonists: knee flexion
• Biceps femoris
• Semitendinosus
• Semimembranosus
Agonists: Knee internal rotation 3
• Semitendinosus
• Semimembranosus
• Popliteus
Agonist: Knee external rotation 1
Biceps femoris
