Lower Extremities Flashcards
The Knee:
- Complex Joint
- how many bones?
- 3 __surfaces enclosed in a common joint capsule
- how many degrees of freedom of movement? meaning it moves in 2 planes
- One of the more frequently injured joints (because in the middle of the body)
3 bones
3 articulating surfaces enclosed in a common joint capsule
2 degrees of freedom
What are the functions of the knee?
Name 3
- transmit loads (remind me of ground forces, every time we jump we are transmit load to the knee
- participate in motion (it rotates, it helps shorten the limb as we walk
- aids in conservation of momentum ( during gait when we are walking, we stretch the quads= passive tension.
how many Joints make up the knee?
- which joint is not part of knee complex? And why
tibiofemoral , largest joint
patellofemoral ( P-F )
- TF joint, because it does not lie within joint capsule.
Degrees of Freedom:
Two DOF:
list 2
- flexion/extension in sagittal plane (x-axis aka m/lateral
- internal/external rotation in transverse plane (y-axis
What is the ROM in the knee TF joint?
- sagittal plane?
- transverse plane?
- full extension:
- when the knee is maximum rotation in 90 degree flexion: External Rotation is ? and IR is what degree?
- 0- 140 degree
- full extension: 0 degree, our knee is lock so there is no movement in transverse plane
- when the knee is maximum rotation at 90 degree: External rotation is 45 degree, and IR = 30 degree
What is the ROM in the knee?
Frontal plane?
- Full extension:
- 30 degree flexion: few degrees only.
- what action?
- voluntary or involuntary?
- 0 degree
- abd/add
- INvoluntary
Functional ROM:
- what degree to what degree lies within norm
- 0-117 degree
Anatomy of the Tibiofemoral Joint:
- double condyloid joint
- two articulating surfaces
- medial
- lateral
- what is the 3rd articulating surface?
- Composed of two bones:??
patella
femur
tibia
Anatomy of Femur:
- 2 condyles (articulating surfaces) separated by ____-
- notch becomes shallow = patella groove
- medial condyle approximately 2/3 inches longer anterior- posterior
- ___condyle extends further distally.
intercondylar fossa/notch
medial condyle
Anatomy of Tibia:
- 2 condyles separated by :
- medial condyle is approx. 50 percent larger
- 2 articular disks = ?…. between femur and tibia.
menisci, act as shock absorber/help deepen the convex on tibia
Knee Menisci:
- ___ as opposed to static structures.
- Describe 3, what kind of disk-like structures?
- open ends, is call? and they are susceptible to?
- Vascularized only in ____
- poorly vascularize in the?
Medial Menisci:
- what shaped?
- Attaches to MCL
- and attach to what muscle?
Lateral Menisci:
- almost circle, 80 percent of a ring, what shaped?
- More loosely attached to tibia so it is….?
- what muscle attach more lateral?
-Dynamic (movement occurs
- asymmetric, wedge-shaped, fibrocartilagenous
- horns, tears
-periphery, meaning the external/outermost.
Thicker outside and more blood, neuro supply- norcireceiptor, propriceptor
- poorly vascularize in the center.
MediaL: attach more securely so more injury
- C shaped
- semimembranosus
Lateral: O shaped
- less susceptible to injury.
- popliteous
what are the functions of the Menisci?
if you don’t have menisci, then it would be bone on bone lead to arthritis.
- list 4
- distribute and absorb forces ( joint reaction)
- enhance joint congruency. How? …it enable contact to articulate each other. When congruency= more stable
- enhance arthrokinematics (joint movement) …. able to move because it is more congruency
- aids in nutrients and lubrication.
Meniscus Tears:
- knee pain, swelling, tenderness, popping/clicking, limited motion.
Meniscus Tears- debridement (to remove)
- central tear: debride(to clean) pieces torn
- Outer periphery: Debride if small or repair if large tear
- Post Operative Treatment: walking in 1-2 days and full activities in 4 weeks
Meniscus Tears- Post operation Repair:
- Immediately:
= knee immobilizer or brace
= flexion to 60 degree
= WBAT with knee locked in \_\_\_\_
- 1 month
= continue with brace but not in ____
= ROM less/greater than 60 degree? - 3-4 months
= return to activities
extension
extension
greater
Tibiofemoral Alignment: measure in lateral for this note
- Frontal Plane:
= Anatomical axes of femur and tibie (x-ray)
= Normal: call it slight valgus. Range is from?
-if less than 170 degree, it is call? aka knock knee
-if greater than 180 degree, it is call? aka bow legged
Tibiofemoral Alignment:
What changes in forces occur at the knee with?
- Genu valgum: increase ____ forces laterally, increase ___ forces medially
- Genu Varum: increase ___forces medially and increase ____forces laterally.
- What structures may be affected by: ?????????
Genu Valgum:
= medial,
= lateral,
Genu Varum:
= medial,
= lateral,
stretch MCL/LCL, compression LCL/MCL, and compress L/M meniscus.
genu valgum or valgus (think of gum sticking together, knock knee)
genu varum
–
- increase compressive forces laterally, increase tensile
- increase compressive forces medially, increase tensile forces latearlly
Valgum:
stretch MCL, compression lateral collateral ligament, and lateral menisci
Varum:
Stretch LCL, compress medial menisus, compression MCL
Tibiofemoral Alignment: second measure, more clinical
Quadriceps (Q) angel measure in (supine), non weight bearing
- formula?
Normal Q angle:
- males?
- females?
- pathological Q angle?
ASIS to midpoint of patella , from midpoint of patella to tibial tuberosity
–
males less than 10 degree
females less than 16 degree
greater than 20 degree.
Arthrokinematics of the Tibiofemoral Joint:
what is the basic orientation of the AOR (instantaneous AOR) for the knee?
- AOR moves as knee moves through ROM. Typical of what type of motion?
(femur, glide and slide as knee flexing anteriorly)
- curvilinear
Aside: basics of arthokinematics
- spin- pure rotation (top). AOR is _____
- glide/slide (skid) ..think of carpal/tarsal
= pure ____/no rotation - roll (ball/wheel?
= ____ and ___ which is ____
fixed
translation
translation and rotation=curvilinear
Aside: Convex/concave rule
- convex on stable concave surface: convex surface slides in ___ direction as motion of bony lever.
- concave on stable convex surface: concave surface slides in ___ direction as motion of bony lever.
opposite
same
Arthrokinematics of the Tibiofemoral Joint:
- standing position= fixed/stable tibia
- 0 to 25 degree flexion (think of squat) = primarily ____, not sliding yet
- Beyond 25 degree flexion= anterior ____ of femur along with _____
- Gliding offsets ____ displacement that would result from _____ alone.
- Meniscus contribute to ___glide. How? because of……
ROLL
anterior gliding, ROLL
posterior, Rolling
anterior glide, wedge-shape
Screw Home/ Locking Mechanism (lock knee in extension)
- Tibia ___ rotation during last 30 degree of knee extension , it is an ___chain because femur is fixed, tibia is moving.
- Greatest during final __ degree.
why?
- asymmetry(not same size, medial condyle is longer) of ….
- _____ tension
- slight lateral pull of…..
~~(tibia is fixed) In femoral on tibial extension, standing up from a deep squat position , femoral condyles roll anteriorly and slide posteriorly on articular surface of tibia. (close chain
continue with screw home mechanism
- with full knee extension:
- tibial tubercles lodged in intercondylar notch
- menisci tightly interposed between femur and tibia
- ligaments taut
External rotation, open chain
5
- femoral condyles
- ACL
- quadricep
Passive Stabilizers of the Tibiofemoral Joint:
- joint capsule, diarthroses joint.
- MCL
- ___omedial femur to anterior tibia
- blends with …
- attaches to ….
- resists/block……
- MCL
- LCL
- lateral femur to ……
- resists/block…..
- does not blend with……
- ACL
- posteromedial aspect of ….to _____intercondylar region of tibia
- taut in knee ____
- resists ……
- what is a test for ACL intact (not damage)? flex knee and I would pull on tibia so if I get excessive movement, ACL is not so strong
- how about PCL? posterior draw test, draw tibia posterior
ACL more to injury, when knee in flexion
- when knee is in flexion with femoral ___Rotation (ACL winds around ____)
- flexion with femoral \_\_\_\_\_ rotation (ACL winds around..................
ACL injury- Reconstruction
- Immediately begin edema control measures
- 1 to 2 weeks
- AROm
- 3-6 weeks
- Progress strengthening - 7-12 weeks
- sports activities without side to side movement or pivoting - 4-7 months
- progress sports
- posteromedial
- capsule
- medial meniscus
- valgus stresses
- fibula head
- varus stress
- does not blend with lateral meniscus
- lateral femoral condyle to anterior
- extension
- anterior tibial translation and Internal rotation
ER; PCL
IR , lateral femoral condyle
Passive Stabilizers of the Tibiofemoral Joint:
PCL
- ___ surface of ____femoral condyle to ___intercondylar region of tibia
- primary restraint to …
- ____is common mechanism of injury.
** Difference btw ACL and PCL regarding to taut? PCL is taut in knee ____ vs ACL taut in knee ___
anterolateral surface of medial femoral condyle to posterior
- posterior tibial translation
- hyperextension
*** PCL is taut in knee flexion, ACL is taut in knee extension
Passive Stabilizers of the Tibiofemoral Joint:
Iliotibial band:
- fascia from tensor fascia lata, glute max and medius
- attaches to ___ and lateral ……
- gives rise to ___ band leads to patella ___ problems
- reinforces ___aspect of knee
- linea aspera of femur and lateral tubercule of tibia
- iliopatellar band, tracking
- anterolateral
Patella:
Function:
- aids in extension by increase ____ of the quadriceps muscle, greater effect at …..degree flexion .
- allows for….. forces , and decrease ….. between quad tendon and femur.
- protection
moment arm, shortest distance between AOR and line of force
20-40
- allows for wider distribution of contract forces lead to decrease pressure and friction between quad tendon and femur.
Anatomy of Patella:
- what shaped?
- largest ___bone
- least ____joint
- how many facets?
triangular
- sesamoid
- congruent
- 3
Kinematics of Patella:
- with knee flexion patella translates ___ and …..
- FULL knee flexion, lead to sinks into femoral ___
- patella also tilts (___ axis, side to side) and rotates (___ axis)~~~lateral condyle sits higher up, superior. Why? patella has to slide to tract laterally.
- Failure of patella to slide, tilt, or rotate properly can lead to :
- restricted ___and ___ ROM
- Patellafemoral tracking problems leads to pain lead to ….
- PF instability lead to….
inferiorly, medial to lateral
trochlea
vertical axis and rotates A-P axis
PF and Knee
tissue damage
subluxation/dislocation
Stabilizers of the patella
- medial/lateral
medial patellar retinacula -> vastus medialis
lateral patella retinacula–> vastus lateralis - Superiorly/inferiorly
- paterlla tendon (ligament
- quadripceps tendon
pic?
Abnormal Lateral forces on the patella :
- what 2 muscles affected?
- if taut, what direction will pull my patella? laterally ……. glut max/medius attach to itb, so if glute is weak, it pull patella medially
- anything that increase the obliquity (laterally) of the pull could cause: list 2
- vastus lateralis
- ITB
1- excessive lateral compression 2- subluxation and or/dislocation laterally
Other Causes of Excessive Lateral Oblique Pull:
- Weakness of ____, my patella go lateral
- Excessive ____ , would increase Q angle, more bow stringing and it will pull my patella laterally.
- Excessive femoral ____, patella go lateral when head of femur rotate internally to fit acetabulum.
- Tight lateral retinaculum/ loose medial retinaculum
- tight ITB
- diminished height of lateral femoral lip
Vastus medialis oblique
- Genu Valgum
- anteversion
Other factors affecting patella alignment/tracking:
- status of ___muscles , affect IT bands.
- position of ……… , depends on IR/ER will change force how patella sit on it.
- mechanics of feet , whatever happen to one affect the other
gluteal muscle
tibial tuberosity
Specific Problems with Vastus Medialis Oblique:
- barely reaches top of the patella
- fibers run more ___rather than _____
vertical rather than oblique
Musculature of the KNee:
Extensors
- Quadriceps, list 4
Flexors- Rotator
- Hamstrings
1- Lateral (what rotation?____ tibia); what muscle_____
2- Media (what rotation____ tibia); What two muscles ____
Flexors: not primary
- List 4
VMO VL VIntermedius Rectus Femoris ---
ER, biceps femoris (long/short
IR, semimembranosus and semitendinosus
--- popliteus- unlocks the knee gracilis sartoruis gastrocs, why? because it crosses the knee
The Hip Joint:
Function: Support….. and transmit…
support weight of HAT (head, arm, and trunks)
transmit forces between pelvis
