Knee To Foot

Question 1

Lower limb bones

Answer 1

▪️femur
▪️patella- sesamoid bone
▪️tibia-medial malleolus
▪️fibula- lateral malleolus

Question 2

Distal femur

Answer 2

▪️lateral and medial condyles (articulating surfaces)

▪️lateral and medial epicondyles- attachments of ligaments (outer surface of condyles)

Question 3

Tibia

Answer 3

▪️anterior margin- sharp ridge that runs down the middle of the bone
▪️tibial tuberosity- big bump that can be felt- attachment of quadriceps
▪️medial malleolus- creates a hinge for ankle joint
▪️soleal line- (posterior) where soleaus muscle attaches
▪️tibial plague- flat surface at top of tibia- medial and lateral condyles that articulates with femur

Question 4

Fibula

Answer 4

▪️connected to tibia by interosseous membrane- separates leg into anterior and posterior but allows blood vessels through
▪️lateral malleolus- comes down further than medial one
▪️head- articulates with tibia
▪️apex- tip of fibula
▪️allows for muscle attachments

Question 5

Knee joint

Answer 5

▪️hinge synovial joint
▪️femur, tibia, patella
▪️tibiofemoral joint, patellofemoral joint
▪️flexion and extension
▪️small amount of rotation is important
▪️translation- bones moving forward and backwards against each other

Question 6

Patella

Answer 6

▪️articulates with femur
▪️glides between space of two femoral condyles
▪️prevents excessive side to side and rotational movements
▪️helps with joint stability
▪️without it, for forces applied in different directions leading to damage to connective tissues

Question 7

Cruciate ligaments

Answer 7

▪️anterior cruciate ligament- resit anterior tibial translation
▪️posterior cruciate ligament- resit posterior tibial translation
▪️intra-capsular but extra-synovial
▪️test for cruciate ligament tear: stabilise femur with one hand and use other to push and pull tibia-if you pull forward and get excessive movement (5mm/ or compare with normal knee) then they have a ACL tear.
▪️ACL tears are more common: (non impact) running forward and quickly change direction (medial rotation with fixed leg)
▪️tendon autograft- remove ACL, cut tendon to exact measurements and replace it

Question 8

Menisci of knee joint

Answer 8

▪️discs made out of fibrocartilage
▪️anterior horn/posterior horn- towards the front and back
▪️medial meniscus- large C-shape, wide base which is well anchored, less mobile so more risk of injury (meniscus cannot move with the femur)
▪️lateral meniscus- tighter and narrower C shape, more mobile so less risk of injury
▪️slants inwards, outer part is thick (red zone- vascular), inner part is thin (white zone- avascular)
-white zone gets O2 through diffusion from synovial fluid
-if white zone is damaged would not be able to heal well

Question 9

Function of meniscus

Answer 9

▪️shock absorber (1/3 of force)
▪️proprioception- unconscious sense of the position of knee
▪️increases contact area of joint (60% in anatomical position)
▪️as it follows contour of femur condyle, they amplify the contact area
▪️spread load more evenly across tibia plateau
▪️act like a sponge- absorbs synovial fluid when flexed and release it when knee extends, on to surface of cartilage.

Question 10

Collateral ligaments

Answer 10

▪️medial collateral ligament - wider, thicker and stronger, blends with joint capsule
-as there is more force on the medial side of the leg, it is more likely to be injured
▪️lateral collateral ligament-thin cord, extra-capsular, quite loose during flexion

Question 11

Unhappy triad

Answer 11

▪️non impact- internal damage occurs first
-ACL➡️MM➡️MCL (which will get damaged first depending on the force applied)
▪️impact- external damage first
-MCL➡️MM➡️ACL

Question 12

Tarsal bones

Answer 12

▪️7
▪️calcaneus- biggest, heel bone where weight is put on
▪️talus-articulates with leg bones to form ankle joint
▪️navicular
▪️cuboid- articulates with metatarsal
▪️medial, intermediate,lateral cuneiform- wedge shaped, articulates with metatarsals

Question 13

Metatarsals and phalanges

Answer 13

▪️1 (big toe)- 5(pinky toe)
▪️Hallux has 2 phalanges
▪️other toes have 3 phalanges

Question 14

Talocrural joint and subtalar joint

Answer 14

▪️talocrural joint- hinge joint between foot and leg (dorsiflexion and plantarflexion)
-shape of talus: wider at the front than the back- allows more movement during plantar flexion as their is more space- more injuries occur during plantarflexion
▪️subtalar joint- between calcaneus and talus-navicular, talus and calcaneus (inversion and eversion)-get more inversion than eversion so most injuries are inversion injuries
-talus stays still where calcaneus and navicular move side to side.

Question 15

Ligaments at the ankle

Answer 15

▪️medial side: deltoid(triangular)- very strong and thick, good at transferring forces.
-as there is less eversion than inversion, it is very stable and has less injuries
▪️lateral side: lots of small thin ligaments which are vector specific(work in narrow planes)
-won’t have enough ligament in each direction to support the joint therefore more injuries

Question 16

Compartments of leg

Answer 16

▪️anterior
▪️posterior- 2 sections deep, superficial
▪️lateral- small
▪️separated by intramuscular septum (thick connective tissue)- from the bone to skin
▪️interosseous membrane between the bone to separate front and back

Question 17

Sciatic nerve

Answer 17

▪️biggest nerve in the body
▪️innervates the entire leg
▪️comes out to lower limb in hip region, and goes down the back of limb
▪️L4-S3: each nerve has a front and back
▪️spits into tibial (posterior)and common fibular(anterior)
nerves
-common fibular splits into superficial and deep fibular nerves
▪️motor function for all muscles
▪️sensory function- lateral 1/2 of leg and most of foot

Question 18

Anterior nerve

Answer 18

▪️deep fibular nerve

Question 19

Lateral nerve

Answer 19

▪️superficial fibular nerve

Question 20

Posterior nerve

Answer 20

▪️tibial nerve

Question 21

Lateral compartment

Answer 21

▪️evertors 
▪️fibularis longus- goes over the foot 
▪️fiburalis brevis- attaches at 5th metatarsal
-both attach to fibula 
-tendons pass behind lateral malleolus

Question 22

Anterior compartment

Answer 22

▪️tibialis anterior- dorsiflexion and inversion
▪️extensor hallucis longus- extends big toe
▪️extensor digitorum longus- extends other toes
▪️fibularis tertius- weak evertor/ dorsiflexion

Question 23

Superficial posterior compartment

Answer 23

▪️triceps surae (2 muscles, 3 heads)- plantarflexion
-gastrocnemius- 2 heads (knee flexor)
-soleus- attaches at soleal line on tibia
-fuse together to form Achilles’ tendon which attaches to calcaneus
▪️plantaris- plantarflexor and knee flexor
-small muscle at back of knee joint which turns into long tendon (not part of Achilles’ tendon)

Question 24

Deep posterior compartment

Answer 24

▪️flexor hallucis longus
▪️flexor digitorum longus
▪️tibialis posterior- plantarflexion and inversion
▪️popliteus- medial rotation of knee (sits across back of knee) -unlocks the knee to beagle to flex it
▪️tendon of muscles pass behind medial malleolus and through tarsal tunnel-to get to plantar surface of the foot