knee Flashcards
femur
know the place
tibia
know the place
Fibula
know the place
Patella-function and action
knee rolls forward and slides to posterior
Patella-“little pan” largest sesamoid
-sesamoid bones increase ability of muscles- produce effective force
-patella slides with in femoral groove
–up during extension
–down in flexion
–1/8 in of cartilage
–keeps femur from sliding off tibia-flexion
–centralizes pull of quad group
Tibiofemoral joint
knee
knee names
tibial femoral and platella femoral joints
bony structure of knee joint
femur
tibia
fibula
platella
ligaments of knee joint
collateral-medial and lateral
cruciate ligament-learn these with regard to the tibial relationship to the femur- Anterior (ACL) and Posterior (PCL)
be able to draw knee joint and its ligament
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Anterior Cruciate Ligament- Purposes
control forward and backward stability to the knee (240)
Posterior Cruciate Ligament- Purposes
control forward and backward stability to the knee
240
collateral ligament
control the lateral movement of the knee
medial collateral ligament
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lateral collateral ligament
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meniscus
help prevent side to side rocking and shifting of the femur. They also absorb shock in the knee joint. The menisci are attached only at the outside of the tibia and are torn frequently.
-slides with the femur backwards/forwards. Live on top of tibial plateau-attached semi-firmly (why they can be torn) Cup shape keeps the knee from rocking/moving side to side, helps femur stay in place.
tendon of the quadriceps
ends in patellar tendon at the tibial/tuberosity/ tibial tubercle
bursae of the knee
a lot of bursae in the knee
ball bearing within the joint
allow for joint to move smoothly and bones not rub on each other
filled with synovial fluid (slipper substance)
Suprapatellar
directly above patella, under quadriceps tendon
Prepatellar
lies on top of patellar, directly under skin. protects against direct blows to knee
Infrapatellar
lies beneath quadriceps tendon and helps to protect tibial tuberosity during kneeling
DEEP
Iliotibial Band ( IT Band or IT tract)
stabilizes the pelvis on the femur, stabilizes the femur on the tibia
use when your pirouetting, up on your leg on, promenading
tendon of the quadriceps ends in the patellar tendon at the…?
tibial tuberosity
closure rotation
The locking mechanism of the knee
femur rotates slightly inward
is any rotation possible within the knee joint
Yes, classified as modified hinge joint. slight 20% to 30%, not healthy, but most dancers compromise the joint to get the 180% turn out.
how does this affect the stability of the knee?
it makes it unstable, it increases the length of the medial colateral ligament
Lock the knees
anatomically- yes the knee must be locked and stable to do anything on the supporting leg
primary anterior muscles acting on knee
during extension extend the leg, straighten the knee Quadricep group 1. rectus femoris 2. vastus medialis 3.vastus intermedius 4.vastus lateralis
popliteus
tiny muscle in knee
the key that unlocks the knee
when hit right it takes you down
small muscle running behind the knee
Primary posterior muscles acting on the knee
during flexion Hamstring group bicep femoris semimebranosus semitendenosus
pes anserinus
Sartorius, gracilis and semitendinosus
all 3 muscles attach to the medial tibia
this might be the mechanism that dancers use to help maintain extension and turnout with less quadriceps activation when the leg is raised to the front
pes anserinus bursitis
often un recognized by doctors
goose foot leg
knee flexion
during flexion the knee rolls backward on tibia, but also slides to the anterior in order to offset the rolling backwards
knee extension
the opposite action happens with knee extension
!!
Why not sit in plie
it is not good to have that much pressure on your knee
can engage muscles but never the relaxed muscles
patellofemoral Compression force
the force pressing the kneecap back against the femur
Is increased as the knee bends deeper from a demi-plie to a grand plie
What types of muscular contraction is/are being used in plies, descending and ascending
descending:eccentric contraction, some fibers elongating and some are retracting
ascending- concentric contraction
pushing the leg straight, shift in brain
knee flexion
hamstrings are primary muscles of knee flexion
knee extension
Quadriceps group, especialy the rectus femoris
What happens when the knee is unlocked and begins to plie?
gravity enters the equation
quads work eccentrically
plie from the back of the knee that starts the plie
external knee rotation
tensor flacia latae
table on 262
internal Rotation
external- bicep femoris ( hamstring) tensor fasciae latae
internal- semimembranosus, semitendinosus, popliteus (when the foot is not bearing weight-tendue) gracilis, sartorius
function of patella
largest sesamoid bone in the body
-all sesamoid bones increase the ability of the muscle within which it is located to produce effective force
patella slides within the femoral groove
Valgus Angulation
shafts of femur are not totally vertical but are slightly angled inwards
Genu Valgum-knock knees- extreme valgus angulation
evaluate knee alignment relative to…
frontal, sagittal, transverse planes
Genu Varum
bow-legged
Genu Recurvatum
hyper extension
Genu Antecurvatum
slightly flexed knees
are straight but look bent
Tibial Torsion
tibia is slightly twisted and rotated inward, so that the child :toes in”
patella slide UP during
extension
patella slide DOWN during
flexion
patella keeps femur from
sliding forward off of the tibia during flexion
patella centralizes the pull of the
quad group
which position disguises the knee deviations
in 5th
know for test
sketch knee joint and associated ligaments medial collateral lateral collateral ligament cruciate "crossed" ligament
Bursae of the knee
Bursae are fluid filled sacs that protect the bones of the knee joint from rubbing upon one another. According to the mayo clinic- each of your knees has 11 bursae
244DAK
Suprapatellar- higher
Prepatellar-lower than supra, on knee cap
Infrapatellar- inside of knee cap
Iliotibial Band IT BAND
stabilizes the femur on the tibia
stabilizes the pelvis on the femur
Closure Rotation
femur rotates medialy with respects to the tibia when locking during extension
Quadricep muscles- function and identity (sperate quiz) table???
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Popliteus Muscle
hamstring of the knee- small, short diagnol muscl lying beneath gastrocnemius-deepest muscle of the posterior knee. It is a weak flexor of the knee, however, it is vital in unlocking the joint from an extended position. its nickname is the key which unlocks the knee.
Pes Anserinus- 3 muscles
sartorius, gracilis, semitendinosus
all three attach onto the medial tibia
also called goose foot
this might be the mechanism that dancers use to help maintain extension and turnout with less quadriceps activation when the leg is raised to the front
Action of the meniscus during flexion and extension of the knee
moves posteriorly during flexion and anteriorly during extension
Patellofemoral compression force
the force pressing the kneecap back against the femur. Is increased as the knee bends deeper form a demi-plie to a grand plie
Hamstrings- function and identity
the hamstring group is the main flexor of the knee
Muscular contraction in plie
Descending- Quadricep eccentric contraction and hamstring- concentric contraction
ascending-Quadriceps- concentric contraction
Tibial torsion
when tibia is turned slightly medially- toes in
Osgood Schlatter’s Disease
inflammation of tibial tuberosity ( where the patellar tendon attaches to tibia) -Caused by quadriceps pulling on patellar tendon which eventually attaches to tibia. Can pull away from the bone.not uncommon in active adolescents involved in sportsPatellar tenditnitis or jumpers knee
Popping in the knee
joint is being reactivated after a period of rest. Synovial membrane is being awakened to secrete synovial fluid to lubricate joint. Normally, not painful. If painful see doctor.
Know about torn cartilage
has to be repaired surgically because there is no blood flow
Jumpers Knee
a condition resulting from overuse of the knee
patellar tendon
a structure that attaches the quad group to the tibia (shin bone)
patella (knee cap)
is a sesamoid (floating bone) incorporated into the patellar tendon. The patellar tendon os also referred to as thr patellar ligament; some anatomists believe that since this structure connects the patella to tibia it should be classified a a ligament. Ligaments connect bone to bone while tendons connect muscles to bone.
tendinitis
simply the inflammation of a tendon. this can be due to numerous factors. some of the more common factors associated with this condition are:
- a rapid increase in the frequency of training, repeated training on rigid surface, improper mechanics during training, genetic abdnormaliities of the knee joint, poor base strength of the quad muscles
- Any or all of these factors can lead to development of patellar tendinitis, sudden increase in intensity of training, transition from one training method to another
ACL prevents tibia
from sliding forward underneath femur
-from anterior medial condyle of tibia to posterior lateral condyle of femur
PCL prevents tibia
from sliding backwards underneath feur- stronger than ACL
-from posterior lateral condyle of tibia to anterior medial condyle of femur
ACL and PCL relax a little during
lateral rotation, thus making joint vulnerable to injury
collateral ligaments bridge the
joint and prevent sideways movement in the knee joint when knee is straight. When knee is bent, collateral ligaments relax, thus making knee vulnerable to injury. Medial is thicker and stronger than lateral. Because they are taut during etension, they help the knee resists hyperextension.
know that torn cartilage in the knee means
torn meniscus. Crescent shaped discs of cartilage which prevent the femur and the tibia from rubbing on each other- OR cartilage torn beneath the knee cap
In which anatomical position, straight or bent, is the knee most vulnerable to inkury? Why?
Dependent on bracing of coll. and cru. ligaments which are slightly relaxed when knee is bent
What is the principal bone of the lower leg?
Tibia- reinforced by fibula which is attachment point for some hamstring muscles
Why does the ability for turnout in the knees increase slightly when in plie?
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Patella has how much carilage?
1/8th inch thick. Thickest in body because of the incredible amount of pressure applied by the quads when knee is flexed
walking down stairs place how much pressure on patella?
600 lbs of pressure
relaxation is only possible when
the knee is slightly flexed. When knee joint is completely extended, rotation is not possible and side to side shifting is not possible
pes aserinus bursitis
often unrecognized by doctors
knee is most vulnerable when…
bent, because all of the ligaments are relaxed that hold the joint together
femur -incredible journey
meniscus prevents this from rocking on side to side
meniscus-incredible journey
C shaped structure, white, flexible
tibia-incredible journey
prevents rocking of the femur on this
joint cavity-joint capsule-incredible journey
the space you are in the cavity is filled with synovial fluid
synovial fluid-incredible journey
clear, viscous liquid
lubricate-incredible journey
synovial fluid serves to lubricate the surfaces
condiles-incredible journey
the ball of the femur, cite of attachment fro acl and pacl, prevent you from falling
cruciate ligament, collateral ligament, IT Band-incredible journey
taut or pulled tight ligaments, means its extension
patella-incredible journey
small, flat, roundish bone
bursae-incredible journey
membrane, surrounds the patella, highest part of the patella, superior
medial meniscus-incredible journey
between femur and tibia
blood supply-incredible journey
cartilage rarely heals because it has non of this
cruciate ligament-incredible journey
may be torn with medial collateral, medial meniscus
knee-incredible journey
you predict that you your dancer will undergo surgery for repair of this
medial collateral ligament-incredible journey
may have been torn with medial meniscus and cruciate ligament
