Kinesiology Exam 2

What runs through the intercondylar notch

cruciate ligaments

where is the femurs place of articulation with the patella

intercondylar groove

which condyle is longer and more curved

medial

fibular head

helps maintain vertical alignment of the tibia, no direct articulation with the femur, attachment for lateral collateral ligament and bicep femoris

what transfers a majority of the load between knee and foot

tibia

osgood-schlatter disease

patellar tendon pulling on the tibia, very pronounced tibial tuberosity

largest sesamoid bone

patella, triangular bone embedded within the quadriceps tendon, curved base and pointed apex (inferiorly), apex is just proximal to knee joint line

where does the patella articulate with the femur

trochlear/intercondylar groove

which cruciate ligament is always taut

ACL

ACL prevents

anterior translation of tibia on femur, runs from anterior surface of tibial plateau in a superior and posterior direction to lateral condyle of femur

PCL prevents

posterior translation of tibia on femur, runs from posterior surface of tibial plateau in a superior and anterior direction to medial condyle of femur

the most ruptured ligament of the knee

ACL, non-contact, valgus collapse, strong quad contraction, excessive external rotation of knee with femur internally rotated

knee dominate landing

increased external moment arm at knee, greater activation of quad, increased strain of ACL

hip dominate landing

external moment arm is shared between hips and knees, less quad activation more hamstrings and glutes

flexed trunk has what effect of patellafemoral stress during running

decreasing it 

PCL injuries

falling on fully flexed knee or dashboard injury, rarely due to sports

MCL ligaments runs from

medial condyle of femur to tibia, attaches to medial meniscus, protects against valgus stress, becomes tight during knee extension

LCL runs from

lateral condyle of femur to fibular head, no attachment to lateral meniscus, protects against varus stress, becomes tight during knee extension for stability

genu varum is associated with

coxa valgus, high medial compartment loading, uni compartmental OA in medial compartment

genu valgus is associated with

coxa vara, increased strain on MCL, high lateral compartment loading

patella baja

lower sitting patella, inferior patellar pole below joint line

patella alta

high sitting patella, inferior patellar pole greater than 20 mm above joint line, may increase patella femoral contact force during flexion

knees closed packed position

full extension with slight ER, 5-10 beyond neutral

genu recurvatum

hyperextension beyond 10 degrees, overstretches posterior structures, stems from poor postural control or neuromuscular patients (stroke)

reinforcers of MCL

sartorius, gracilis, and semitendinosus

what does the bicep femoris and popliteus helped reinforce

posterolateral supportm reinforces ACL, PCL, and LCL

the gastrocnemius and popliteus help support

posterior reinforcement

ITB helps to reinforce

anterolateral

which meniscus has more injury and is less mobile

medial

3 zones of the menisci

peripheral 1/3 is vascularized (red), inner 2/3 is non-vascularized (white zone), transition is the the pink zone

what is the purpose and what happens if menisci is removed

it triples the joint contact, so removal increase magnitude of forces going down onto the knee, and changes size and location of contact area

common mechanisms of injury for menisci

with ACL, axial rotation over flexed, weight bearing knee

unhappy triad

MCL, lateral meniscus, ACL, caused by outside valgus force when planted and ER

what stabilizes the patellofemoral joint

bony structure, quadriceps, passive restraint from surrounding soft tissues

during tibia on femoral movements what does the patella do

open chain- patellas slides relative to fixed trochlear groove

with femoral on tibial movements how does the patella move

closed chain- remains relatively fixed

open chain patella movement 135 degrees

superior pole of patella contacts femur below trochlear

open chain patella movement 90

contact position of patella is moving inferiorly, between 90 and 60 the patella is well engaged with trochlear groove, greatest contact point

open chain patella moment near full extension

patella is proximal to trochlear groove, increased moment with relaxation of quads

Q-angle aka patellafemoral angle

angle between quads muscle and patella tendon, meausred by line from ASIS to mid patella, line tibial tuberosity to midpoint of patella, measure angle in between the lines

normal q angle 

13-18, greater in females, abnormal might lead to patellafemoral pain syndrome

studies show what relationship between sham surgery and partial meniscus repairs

they have the same results

what makes a q angle greater

wider hips, bowstring or lateral force

what causes a lateral force on the patella

tight TFL and weak vastus medialis oblique fibers

what is the maximal knee extension internal torque

45 degrees, driven primarily by moment arm of patella

what is the external torque during open chain

increases from 90 to 0 degrees of knee flexion

what is external torque during closed chain

decreases from 90 to 0 degrees of knee flexion

external torques are the greatest for open chain

0-45

external torques are greatest for closed chain

45-90

alternate positions for less stress on patellafemoral joint is 

open chain- 90-45

closed chain 0-45

quad full range without excessive external torque

the flexor internal occurs at

5 degrees, due to active insufficiency of hamstrings, (the most active insufficieny is knee flexed and hip extended)

why is the knee a pseudo hinge synovial joint

screw home mechanism has rotation

transverse plane motion of the knee

internal 15, external 30 degrees, at 90 degrees of flexion, secondary to bony geometry

closed chain the medial condyle being longer and more curved will cause

femur to move medial rotation in closed chain

to unlock from extended knee in closed chain

the popliteus will laterally rotate the femur

during open cahin movement screw mechanism is 

the tibia will rotate laterally as knee is extended 

what bones make up the talocrural joint

tibia, fibula, talus

what makes up the rearfoot

talus, calcaneus, subtalar joint

what makes up the midfoot

tarsal bones( cuboid, navicular and cuneiforms), transverse tarsal joint, distal intertarsal joint

what makes up the forefoot

metatarsals and phalanges, all joints ditsl to and including tarsometatarsal joints

what does the lateral malleolus act as 

pulley fibularis longus and brevis

what does the fibula articulate with

tibia and talus, only transfers 10% of weight

what does the tibia articulate with

talus and fibula, transmits lots more weight

most superiorly located bone on body

talus

what joints are the talus found in

talocrural and subtalar joints

what surface does the talus have

concave dorsal surface 

what does the calcaneus articulate with

cuboid and talus

what attaches on calcaneus

achilles tendon and plantar fascia

what does the navicular articulate with 

talus and 3 cuneiforms

what landmark is used to mark for arch collapse

navicular

which bones contribute to the transverse arch of the foot

cuneiforms

what articulates with the cuneiforms

navicular and base of 3 medial metatarsal

cuboid has 6 surfaces and articulates with

calcaneus, talus, navicular, lateral cuneiform, 4th metatarsal and 5th metatarsal

what shape of the head on metatarsals

convex heads to articulate with phalanges concave base

what plane and axis is DF and PF

sagittal plane, frontal axis

what plane and axis is eve and inv

frontal plane, sagittal axis

what plane and axis is ABD, ADD

transverse plane, vertical axis

medial and lateral malleolus don’t line up resulting in

oblique axis

open chain supination

forefoot PF, calcaneal inv, forefoot ADD

open chain pronation

forefoot DF, calcaneal eve, forefoot ABD

closed chain supination

calcaneal inv, talar DF, talar abd

closed chain pronation

calcaneal eve, talar PF, talar add

talocrural joint has 1 degree of freedom

PF, DF, HOWEVER, axis of rotation is not parallel to ground, 10 tilt in frontal, 5 tilt in horizontal (medial malleolus is anterior and superior to lateral)

how does the talus move in DF

roll anterior and slides posterior

what is the closed pack position of the ankle and how is it useful

full DF, locked position to push off of in walking

open packed position of the ankle

10 degrees of PF

at initial gait what does the ankle do

ankle is PF to assist in absorping the forces

throughout gait cycle

ankle moves towards DF, reaches max right before push off (stable position ready to accept compression forces)

subtalar joint consists of how many articulations

3 between calcaneus and talus, the posterior one being the largest

does supination or pronation help absorb forces better

pronation

how does the subtalar joint aid in push off of gait

move into supinated to stiffen subtalar for push off

wear on bottom of foot for supinator

outer borders, high arch

transverse tarsal joints has two articulations

talonavicular and calcaneocuboid, connects rearfoot and midfoot, assist with supination and pronation and absorption of forces and adaptation

what assists with changing the medial longitudinal arch during gait

transverse tarsal joint- assist with adaptation of surfaces

the transverse tarsal joint has more 

supination, minimal clinical relevance because it is difficult to separate talocrural and subtalar

what is forefoot valgus

eversion of forefoot and hindfoot in subtalar neutral, pinky toe is higher

what does forefoot valgus contribute to

lateral ankle sprains, IT band syndrome, plantar fasciitis

what is forefoot varus

inversion of forefoot on the hindfoot in subtalar neutral

what does the forefoot varus contribute to

TP tendonitis, PFPS, plantar fasciitis

what is the medial longitudinal arch comprised of

calcaneus, talus, navicular, cuneiforms, medial three metatarsals