LL4. knee/ankle/foot Flashcards
what type of joint is knee joint
→ hinge type synoival joint
where is knee joint most stable
- Most stable in extension
- condyles sit better in plateau
function of menisci
2 menisci on which condyles of femur rest = increases area of contact
function of cruciate ligaments
cruciate ligaments bind the femur to tibia to prevent sliding
function of collateral ligaments and patella
further reinforce joint to help quad femoris
patella structure
- sesamoid bone
- sits front of knee joint in patellofemoral groove of femur
- attaches to quadriceps tendon (s) and patellar ligament (i)
patella function
- leg extension = enhances leverage that quad tendon exurts on femur increasing efficiency
- protection = protects anterior aspect of knee joint from trauma
- reduces friction in tendon
most common dislocation of patella
- most commonly dislocates laterally
- because femur is at an angle due to femoral neck
- vastus medialis and lateral condyle prevents patella moving laterally
what is Patellar ligament and its attachment
a continuation of the quadriceps femoris tendon distal to the patella.
It attaches to the tibial tuberosity.
describe the condyles of the femur
- lateral (bigger)
- acts as resistance to prevent patella moving laterally
- medial
function of medial and lateral menisci
- fibrocartilage structures
- deepen articular surface of tibia to increase stability of joint
- act as shock absorbers by increasing surface area
difference between medial and lateral menisci
- medial meniscus
- wider
- fixed to the tibial collateral ligament and the joint capsule
- less mobile
- lateral meniscus
- circular
- smaller
- does not have any extra attachments, rendering it mobile
which meniscus is fixed to the medial collateral ligament
medial = lateral is more mobile
function of medial and lateral collateral ligaments
- extension = taut (tight)
- prevents side to side movement of tibia on femur
- stabilise the hinge motion of the knee, preventing excessive medial or lateral movement
difference between medial (tibial) and lateral (fibular) collateral ligaments
- medial (tibial) = wide and flat
- attachments:
- medial epicondyle of femur
- medial miniscus
- attachments:
- lateral (fibular) = thinner and rounder
- attachments:
- lateral epicondyle of femur
- head of fibula
- attachments:
function of cruciate ligaments
connect femur and tibia and prevent dislocation
structure and function of ACL
from anterior intercondylar area of tibia → medial aspect of lateral femoral condyle
- prevents anterior dislocation of tibia onto femur
- Prevents posterior rolling of femur on tibia
what movement would cause damage to ACL
force to lateral aspect + medial twist movement = damage
structure and function of PCL
from posterior intercondylar area of tibia → lateral aspect of medial femoral condyle
- prevents proximal dislocation of tibia on femur
- Prevents anterior rolling of femur on tibia (downhill)
blood supply to knee joint
genicular anastomoses around knee from femoral and popliteal arteries
function of popliteus
lateral condyle → round
Unlocks the knee
Rotates femur laterally
Assists in flexion
muscles allowing extension of knee
Produced by the quadriceps femoris, which inserts into the tibial tuberosity.
muscles allowing flexion of knee
Produced by the hamstrings, gracilis, sartorius and popliteus
muscles allowing lateral rotation of knee
Produced by the biceps femoris.
muscles allowing medial rotation of knee
Produced by five muscles; semimembranosus, semitendinosus, gracilis, sartorius and popliteus.
articulation at knee joint
femoral → tibial condyles
tibiofemoral surface
surface covered with hyaline cartilage to allow less friction
patellofemoral surface
- anteriordistal ends of femur
- patella sits in groove
- hyaline cartilage
osteoarthritis of knee
- cartilage breaks down due to wear and tear → stiffness
- damage to ligaments
- tricompartmental
what is knee lock
give quads etc rest while keeping body extended
ankle joint articulations
formed between distal ends of tibia and fibula and talus
bones of ankle/foot
Talus
Calcaneus
Navicular
Cuneiform (MIL)
Cuboid
Metatarsals
Phalanges
what keens tendons of foot tight
Flexor retinaculum
function of arches of foot
⇒ Distribute body weight/Shock absorber
where is Transverse arch
ball of foot
where is Medial longitudinal arch
between first metatarsal and calcaneous
where is Lateral longitudinal arch
between 5th metatarsal and calcaneous
contents of layer 1 of foot (most superficial)
Flexor digitorum brevis
Abductor hallucis
Abductor digiti minimi
abductor hallucis AOAI
layer1
ACTION: abduction and flexion of great toe
ORIGIN: calcaneus/flexor retinaculum/plantar aponeurosis
ATTACHMENT: proximal phalanx of great toe
INNERVATION: medial plantar nerve
flexor digitorum brevis AOAI
layer1
ACTION: flexion of lateral 4 toes
ORIGIN: calcaneus/plantar aponeurosis
ATTACHMENT: middle phalanges of lateral 4 digits
INNERVATION: medial plantar nerve
abductor digiti minimi AOAI
layer1
ACTION: abduction and flexion of little toe
ORIGIN: calcaneus/plantar aponeurosis
ATTACHMENT: base of proximal phalanx of pinky toe
INNERVATION: lateral plantar nerve
muscles in second layer of foot muscles
lumbricals
quadratus plantae
quadratus plantae AOAI
layer2
ACTION: helps flex lateral toes
ORIGIN: calcaneus/plantar aponeurosis
ATTACHMENT: tendons of flexor digitorum longus
INNERVATION: lateral plantar nerve
lumbricals AOAI
layer2
ACTION: flexes MTP joints and extends IP joints
ORIGIN: tendons of flexor digitorum longus
ATTACHMENT: extensor hoods of lat 4 digits
INNERVATION: lateral - lateral plantar nerve
medial - medial plantar nerve
muscles in third layer of foot
flexor hallucis brevis
adductor hallucis
flexor digiti minimi brevis
flexor hallucis brevis
layer3
ACTION: flexion of great toe at MTP
ORIGIN: bones/posterior tibialis tendon
ATTACHMENT: base of great toe
INNERVATION: medial plantar
adductor hallucis
layer3
ACTION: adduction of great toe/transverse arch
ORIGIN: bases of metatarsals
ATTACHMENT: base of great toe
INNERVATION: D lateral plantar nerve
flexor digiti minimi brevis AOAI
layer3
ACTION: flexion of little toe at MTP
ORIGIN: base of 5th MT
ATTACHMENT: prox phalanx of 5th digit
INNERVATION: S lateral plantar nerve
muscles in fourth layer of foot (deepest)
plantar interossei
dorsal interossei
plantar interossei AOAI
layer4 = 3 muscles
ACTION: adduction of lateral 3 digits/flexion of MTP joints
ORIGIN: medial MT 3-5
ATTACHMENT: medial phalanges 3-5
INNERVATION: lateral plantar nerve
dorsal interossei AOAI
layer4 = 4 muscles
ACTION: abduction of lateral 4 digits/flexion of MTP joints
ORIGIN: lat MT 3-5
ATTACHMENT: lat phalanges 3-5
INNERVATION: lateral plantar nerve
aching and numbness on medial sole of foot
medial plantar nerve can become compressed and irritated as it passes deep to the abductor hallucis muscle.
what does medial plantar nerve innervate (FAFF)
- flexor hallucis brevis
- abductor hallucis
- flexor digitorum brevis
- first lumbrical
what does lateral plantar nerve innervate
everything except the faff
- flexor hallucis brevis
- abductor hallucis
- flexor digitorum brevis
- first lumbrical
what innervates the heel
tibial nerve
what innervates medial side of foot (3.5 toes)
medial plantar nerve
what innervates lateral side of foot (1.5 toes)
lateral plantar nerve
