Knee Biomechanics

Question 1

Describe the C, CPP, RP, OK and EF of the tibiofemoral joint.

Answer 1

i) synovial, compound, complex, bicondylar functioning as modified ovoid
ii) flex > ext
iii) full extension and tibial ER
iv) RP 30 deg flex
v) flex/ext, tibial IR/ER
vi) capsular ext, soft tissue approximation flex

Question 2

Describe the arthrokinematics of the tibiofemoral joint.

Answer 2

CKC:

i) ext: anterior roll of femur and posterior glide (w/ femoral IR)
ii) flex: posterior roll of femur and anterior glide

OKC:

i) ext: anterior roll of tibia, anterior glide
ii) flex: posterior roll of tibia, posterior glie

Note in ext there is conjunct tibial ER (anterior glide of medial and posterior glide of lateral tibial condyles), and the opposute for flex

Question 3

Describe the arthrokinematic movement of the menisci.

Answer 3

Believes to be pulled posteriorly (med < lat) by semimembranosis and popliteus in open chain flexion. Move anteriorly in open chain extension (med < lat). mm movements.

Question 4

Describe the C, CPP, RP, DoF and EF of the PF joint.

Answer 4

i) synovial, compound, modified sellar
ii) extension
iii) 30 deg flex
iv) one DoF (superior and inferior glides associated w/ tilting, rotating and tipping)
v) ligamentous end feel all directions

Question 5

Describe the OK of the PF joint.

Answer 5

i) in extension, rests laterally above supratrochlear fat pad
ii) 10-20 patella descends and moves medially, contact on inferior patella
iii) 30-60 patella moves so middle articular surface is in contact
iv) 60-90 the upper surface is in contact
v) Past 90 patella moves laterally again, quad tendon enters trochlea
vi) at 135 the odd facet (medial aspect of med articular surface) contacts lateral aspect of the medial condyle, final motion is lateral glide w/ medial tilt

Question 6

Describe how OKC and CKC affect the PF joint.

Answer 6

i) increase joint reaction forces in OKC flexion and CKC extension
ii) improved force dissipation in flexion 2’ greater surface area
iii) CKC exercises produce less compression in 0-45
iv) OKC exercise produce less compression in 10 deg and less and > 50 deg

Question 7

Describe the C, CPP,of the superior tibiofibular joint.

Answer 7

i) simple, planar, synovial

ii) pain w/ contraction of biceps fem

Question 8

Describe the OK of the superior tib fib joint.

Answer 8

i) knee flex: moves anteriorly
ii) knee ext: moves posteriorly due to pull of biceps fem
iii) ankle dorsiflexion: superior, anterior and lateral movement of the fib head
iv) ankle PF: inferior, posterior and medial movement of fib head

Question 9

Describe the arthrokinematics of the superior tib fib joint.

Answer 9

posterior glide w/ DF and anterior glide w/ PF

Question 10

Describe the C, CP, CPP, RP, OK and AK of the inferior tib fib joint.

Answer 10

i) syndesmotic
ii) pain w/ splayed (WBing squat or DF)
iii) WBing DF
iv) superior lateral translation w/ tibial IR and DF
v) minimal AP glides