Knee Flashcards
What objective is fulfilled by the critical event of neutral knee in initial contact?
Ensures heel contact
What is the arc of motion at the knee during loading response?
0-20 Flexion
What objective does the 20 degrees of Flexion in loading response fulfill?
Shock absorption
What is the arc of motion at the knee in midstance?
20 Flexion to 0
What objectives does the 20 degrees of extension in midstance fulfill?
Progression of COM over BOS
Single limb stance stability
What is the arc of motion at the knee in terminal stance?
Remains at 0
What objectives are fulfilled by the knee remaining at 0 in terminal stance?
Progression of COM over BOS
What is the arc of motion at the knee during pre-swing?
0-40 Flexion
What objectives are fulfilled by the 40 degrees of Flexion in pre-swing?
None
What is the arc of motion at the knee during initial swing?
40-60 Flexion
What objectives does the 20 extra degrees of flexion In initial swing accomplish?
Foot clearance
What is the arc of motion at the knee during mid-swing?
60-30 Flexion
What objective are fulfilled by the 30 degrees of extension in mid-swing?
Limb advancement
What is the arc of motion at the knee during terminal swing?
30 Flexion - 0
What does the 30 degrees of knee extension In Terminal swing accomplish?
Limb advancement
Ensures normal stride length and heel contact
What is the knee motion in the frontal plane throughout the gate cycle?
Neutral varus/valgus
What is the motion of the tibia and femur in the frontal plane from loading response to midstance?
What is the arc of motion of the tibia and femur in the transverse plane from midstance to terminal stance?
External rotation to neutral
What does the screw home mechanism do during loading response?
Rear foot pronation -> tibial internal rotation -> unlocks the knee to facilitate knee Flexion and shock absorption
What does the screw home mechanism do at midstance?
Foot supination -> tibial eternal rotation -> locks knee to facilitate knee extension and ensure stance stability during single limb support
What is the arc of motion at the knee in initial contact ?
Neutral
What is the moment at the knee during loading response?
Knee Flexion moment
What is the muscle action at the knee during loading response?
Vasti (eccentric)
What is the moment at the knee during midstance?
Knee Flexion moment to neutral moment
What is the muscle action at the knee during midstance?
Vasti (concentric)
What is the moment at the knee during terminal stance?
Neutral moment
What is the muscle action at the knee during terminal stance?
No quadriceps action
What is the moment during pre-swing at the knee?
Knee Flexion moment (small)
What is the muscle action at the knee during pre-swing?
Knee Flexion is passive!
What is the moment during initial swing at the knee?
Extension moment (gravity driven)
What is the muscle action at the knee during initial swing?
Biceps femoris short head (concentric)
What is the moment during mid-swing at the knee?
Extension moment (gravity driven)
What is he muscle action at Thea knee during mid-swing?
No muscle action
What is the moment during terminal al swing At the knee?
Flexion moment
What is the muscle action at the knee during terminal swing?
Vasti (concentric)
What is the frontal plane moment at the knee during loading response - terminal stance?
Varus moment
What structures resist the varus moment at the knee during loading response to terminal stance?
IT band and LCL
What controls the ER of the tibia?
Medial hamstrings
Pets anserine complex
LCL and MCL
Popliteus
What controls tibia IR?
Lateral hamstrings
ACL
What 3 muscles control femur rotation?
Glut max
Piriformis
Deep hip rotators
