The Knee - Osteo/Arthrokinematics

Question 1

osteokinematics of tibiofemoral

Answer 1

flex/ext
IR/ER
abd/adduction

Question 2

arthrokinematics of tibifemoral flexion in OKC and CKC

Answer 2

OKC: posterior roll and glide
CKC: posterior roll and anterior glide

Question 3

arthrokinematics of tibiofemoral extensions in OKC and CKC

Answer 3

OKC: anterior roll and glide
CKC: anterior roll and posterior glide

Question 4

screw home mechanism

Answer 4

external rotation of tibia with terminal extension, about 10 degrees

motion most evident in final 5 degrees

knee must unlock by popliteus prior to performing flexion by 1st medially rotating then flexing

Question 5

if there is restraint to the IR prior to flexion in the screw home mechanism, what could happen

Answer 5

deterioration of the knee

Question 6

frontal plane motion

Answer 6

valgus with extension

varus with flexion

Question 7

what is the closed pack position of the tibiofemoral

Answer 7

full ext

Question 8

what is the open pack position of the tibiofemoral

Answer 8

25 degrees of flexion

Question 9

what is the capsular pattern of the tibiofemoral

Answer 9

flexion&raquo_space; extension

Question 10

what is the function of the patellofemoral

Answer 10

pulley for quad –> more torque can occur

ability of patella to function is dependent upon patellar mobility

Question 11

patellofemoral joint congruency

Answer 11

patella lies on femoral sulcus in full extension –> minimal joint congruency

the contact btw patella and femur changes with ROM –> max congruency in flexion

Question 12

what happens if there is less than optimal congruency or subtle structural anomalies of the patellofemoral joint

Answer 12

abnormal tracking of the patella

patellofemoral pain syndrome

Question 13

when there is incongruency in the patellofemoral joint, what does it rely on for stability?

Answer 13

static and dynamic passive structures

Question 14

what can occur in near or full extension of the patellofemoral joint?

Answer 14

lateral dislocation or subluxation

decreased fit of patella within trochlear groove of femur and lateral line of force of the quad

Question 15

what is the function of the patella?

Answer 15

a spacer btw femur and quad

increase IMA of the knee extensor mechanism

torque is the product of force and its moment arm –> patella increase extension torque at the knee

Question 16

when is the knee extensor moment arm the greatest

Answer 16

btw 20-60 degrees of knee flexion

Question 17

patellofemoral joint kinetics

Answer 17

exposed to high loads of compressive forces

increased compressive forces with increased knee flexion

Question 18

patellofemoral motions

Answer 18

flex/ext
medial/lateral shift
medial/lateral tilt
medial/lateral rotation

Question 19

what degrees of extension produces the greatest torque

Answer 19

45-0

Question 20

what degrees of knee flexion is the greatest when squatting

Answer 20

45-90

Question 21

what is a safe landing pattern

Answer 21

small knee EMA
larger hip EMA
increased hamstring to quad contraction pattern

Question 22

what is an unsafe landing pattern

Answer 22

larger knee EMA
smaller hip EMA
high activation of quads
stiffer landing

Question 23

what exercises can you shift to a quad dominant position

Answer 23

squats, lunges, etc.