knee- applied kinesiology

what is the knee composed of?

• 3 bones

• 3 articulating surfaces

• 1 joint capsule

what bones is the knee composed of?

• femur

• tibia

• patella

which joint is the largest joint in the body?

knee

which joint is frequently injured in the body?

knee

what does the knee provide?

provides critical motions as it pertains to activities of daily living (ADLS) and participation in sport activities

why is the knee the most frequently injured?

because it is positioned between two long bony levers

what are the landmarks of the distal femur?

• epicondyles

  -medial

  -lateral

• adductor tubercle

• patellar facet

which epicondyle is larger?

medial epicondyle

what are the epicondyles important for?

important for attachment sites

how do the epicondyles connect?

connect anteriorly BUT separated posteriorly

what is the adductor tubercle?

where adductors insert

is the patellar facet flat?

NO! it is not flat

what are the landmarks of the proximal fibula?

• head of fibula

• neck of fibula

what are the landmarks of the proximal tibia?

• tibial plateau

• intercondylar eminence

• tibial tuberosity

• gerdys tubercle

what is the tibial plateau?

1. medial

2. lateral

which tibial plateau is larger?

medial is larger

what is the intercondylar eminence?

space between plateaus

what is the tibial tuberosity?

big bump in front of knee

what is the gerdys tubercle?

attachment site for IT band

what are the landmarks of the patella?

• poles

• facets

how are the poles on the patella described?

superior and inferior

how are the facets on the patella described?

lateral and medial

what are the 3 distinct joints that work together at the knee?

• tibiofemoral

• patellofemoral

• proximal tibiofibular joint

which is the largest sesamoid joint in the body?

knee

what is the tibiofemoral joint?

articulation between the femoral condyles and the tibial plateau

where does the tibiofemoral joint get its support?

• menisci

• cruciate ligaments

• joint capsule

• collateral ligaments

what is the menisci?

fibrocartilaginous rings

what does the menisci look like?

• thicker exteriorly

• thinner inside

is the minisci vascular or avascular?

largely avascular

• does not have good blood supply

can be the menisci be surgically repaired?

yes.

what are the functions of the menisci?

• weight bearing

• joint stability

• joint movement

• nutrition/ lubrication

what is the medial meniscus?

C chaped

which meniscus is larger?

medial meniscus

what is the medial meniscus attached to?

joint capsule

what is the insertion for the medial meniscus?

semimembranosus insertion

what is the lateral meniscus?

Oval shaped/ O shaped

which meniscus is smaller?

lateral meniscus

which meniscus is more mobile?

lateral is more mobile than medial

what is the insertion for the lateral meniscus?

popliteus muscle insertion

which is the largest joint capsule in the body?

tibiofemoral joint capsule

what is the tibiofemoral joint capsule?

ligamentous capsule surrounding knee joint

what are the layers of the tibiofemoral joint capsule?

• synovial layer

• fibrous layer

where is the synovial layer of the tibiofemoral joint capsule?

innermost layer, more lubricated

where is the fibrous layer of the tibiofemoral joint capsule?

outside layer, stronger

what are the cruciate ligaments known for?

crossing

what do the cruciate ligaments look like?

what are cruciate ligaments?

intracapsular, but outside synovial layer of joint capsule

what does the anterior cruciate ligament look like?

anterior cruciate ligament

O: posteromedial aspect of lateral femoral condyle

I: just anteromedial to the intercondylar eminence

who is more likely to tear their ACL?

females are 8x more likely

how many bands of fibers does the ACL have?

3 bands of fibers

what are the 3 bands of fibers of the ACL?

• anteromedial

• intermediate

• posterolateral

when the anteromedial band is stretched what happens?

there can be more risk of injury

what does the intermediate band do?

fills in gaps between anteromedial and posterolateral

what is the main function of the ACL?

• prevent anterior displacement of tibia on a fixed femur

what are some other functions of the ACL?

• prevent excessive rotation of the tibia on a fixed femur

• secondary support to varus and valgus forces

what does the posterior cruciate ligament look like?

is the PCL shorter or longer than the ACL?

shorter and THICKER than ACL

posterior cruciate ligament

O: lateral surface of medial femoral condyle

I: posterior to the intercondylar eminence

what are the differences between PCL and ACL?

• PCL is SHORTER

• PCL is THICKER

• PCL is STRONGER

• PCL is LESS OBLIQUE

where are most PCL injuries going to occur?

seen more in car accidents than sports injuries

PCL tear

does the PCL need to be repaired?

doesnt really need to be repaired

can we function without our PCL?

yes we can still function without it

what does the medial collateral ligament look like?

what are the 2 components of the MCL?

• deep fibers

• superficial fibers

what is the function of the MCL?

• restrict valgus forces

• prevent excessive rotation

what do the deep fibers of the MCL attach to?

medial meniscus

what does the lateral collateral ligament look like?

lateral collateral ligament

O: lateral femoral condyle

I: head of fibula

what is the LCL function?

protect against varus forces

is the LCL intracapsular or extra capsular?

extracapsular (not within joint capsule)

valgus vs. varus forces

what is a varus rotation?

medial deviation

what is a valgus rotation?

lateral deviation (Disney knees)

what does the patellofemoral joint look like?

what is the patellofemoral joint?

patella rest in trochlea of femur

is the patella mobile or immobile?

patella is extremely mobile

what is the description of the patellofemoral joint?

thick articular cartilage on posterior aspect of patella

when at resting position, is the patellofemoral joint in extension or flexion?

full extension

when at a fully flexed position is the patellofemoral joint stable or unstable?

more stable at a fully flexed position

what are the motions of the patellofemoral joint?

• flexion

• extension

what are the static restraints of the patellofemoral joint?

• medial retinaculum

• lateral retinaculum

• patellotibial ligaments

• patellofemoral ligaments

• Iliopatellar band