Knee joint Quiz

What muscle directly unlocks the knee so that flexion may begin?

Popliteus

If someone tore their ACL there would not be a clear endpoint to _______ translation of the tibia with respect to the femur

Anterior

During knee extension rolling and gliding terminates on which condyle of the femur first causing it to act as a pivot point for the locking of the knee.

Lateral

What is true regarding the knee joint axis of rotation for flexion extension

• Passes through the distal end of the femur

• Oriented mediolaterally

• Moves as the knee goes through the full range of motion

An impact to the outside of the knee directed inward (or medially) would most likely endanger which ligament

MCL

What type of cartilage is the meniscus

Fibrocartilage

What is true about the patella

• Increases moment arm of the quadriceps about the knee joint center

• increases the torque generating capacity of the quadriceps

The distal medial and lateral condyles of the femur are?

Convex mediolaterally and anteroposterioly

What muscle does not play a role in knee flexion

Soleus

The screw home mechanism in final knee extension happens closed chain as internal rotation of the femur on a fixed tibia

true

Lateral/External rotation of the tibia with respect to the femur may occur voluntarily when the knee is flexed by activating what muscle primarily

Biceps femoris

As the knee flexes beyond 25 degrees what are the arthrokinematics of the femur on the tibial plateau

Rolls posteriorly and glides anteriorly

Both the arcuate ligament and the oblique popliteal ligament resist what?

Knee hyperextension

The axial rotation achievable at the knee joint exists because why?

Low congruence of the knee joint and the joint laxity

What position given an active and constant tension in the quadriceps muscle would most dramatically increase the compression of the patella against the femur

Knee flexed to 120 degrees

Where is the pivot point or axis of rotation during volitional axial rotation of the knee at 90 degrees of flexion

Medial intercondylar tubercle of the tibia

What muscle can most effectively act as a dynamic restraint for the anterior translation of the tibia with respect to the femur?

Semitendinosus

What joint is a broader ligament whose posterior fibers are continuous with the joint capsule of the knee

MCL

True or False: The ACL can help resist varus stresses at the knee but cannot resist valgus stresses at the knee

False

When the hip is in a flexed position, knee extension may be limited in part due to

Passive insufficiency of semimembranosus

What muscle is biarticular

Sartorius

If vastus medialis, vastus lateralis, and vastus intermedius muscles are isometrically contracting and the biceps femoris is concentrically contracting what joint movement should be happening

Hip extension

True or False: A more retroverted hip will predispose an athlete to a valgus knee collapse during a squat

False

If the soleus is contracting isometrically and the gastrocnemius is contracting eccentrically, what joint movement is implied

Knee extension

When the ACL tears in a knee flexed, valgus position with internal rotation of the femur, it tears because whay?

Wraps around the lateral femoral condyle

What combination should be paired with a larger Q angle

Anteverted hip and genu valgum

Do ligaments act in compression to resist movement at a joint

no

The valgus position at the knee is the same joint position at the knee which results from open chain knee ____

Abduction