Knee And Ankle (7B) Flashcards
Bones and pertinent bony landmarks of the knee (leg)
- lateral condyle
- medial condyle
- head of the fibula
- tibial tuberosity
- tibia
- fibula
- lateral malleolus
- medial malleolus
Bones and pertinent bony landmarks of the foot
Tarsals (going from proximal row from the first digit area to the 5th digit area and make a backwards C to one more tarsal bone in distal row)
- medial cuneiform
- intermediate cuneiform
- lateral cuneiform
- cuboid
- navicular
- talus
- calacenus
Joints of the knee
- tibiofemoral joint
- patellofemoral joint
Tibiofemoral joint
- hinge joint (but the knee also slightly rotates)
- proximal surface of tibia is covered with menisci (meniscus = singular) which is similar to the TFCC articular disc in the wrist
- little bone to bone contact, so the knee is supported by ligaments =
- anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL)
- tibial collateral ligament (medial side) and fibula collateral ligament (lateral)
Patellofemoral joint
- modified gliding joint
- patella = largest sesamoid bone in the body
- superior = quadriceps tendon
- inferior = patellofemoral tendon
- patella increases efficiency (angle of pull) of the quadriceps
- as knee flexion increases, the more tight the patella becomes on the femur, as it glides distally
Joints of the ankle
- talocrural joint
- subtalar joint
Talocrural joint
- hinge joint
- talus bone of the ankle against the malleoli of leg bones
- Dorsiflexion and plantar flexion (sagittal plane)
Subtalar joint
- hinge joint but perpendicular to talocrural
- between talus and calcaneus bones
- eversion and inversion (frontal plane)
Joints of the foot
- it mirrors the hand except it has MT joints (metatarsal-phalangeal) instead of MC joint
- also called PIP and DIP joints
Knee muscle movers
- two joint muscles
- also moves the hip
Hamstring group
Medial to lateral:
- semimembranosus
- semitendinosus
- biceps femoris (long and short heads proximally)
the only one that is NOT a two-joint muscle of the hamstrings = short head of biceps femoris (cannot extend the hip)
Attachments of hamstring group
- proximal = ischium (except for the short head of biceps femoris which attaches at posterior femur, not crossing the hip)
- distal = semis on medial tibia and biceps on lateral fibula
Innervation of hamstring group
- sciatic nerve
Actions of hamstring group
- flex the knee
- externally rotate the flexed knee
Long head: - extend the hip
- externally rotate the hip (assist)
- tilt the pelvis posteriorly
Popliteus
- “the key that unlocks the knee” = closed chain
- in order to flex the knee, the knee needs to “unlock” from full extension (femur needs to rotate laterally - external rotation)
Attachments of popliteus
- proximal = lateral condyle of femur
- distal = proximal, posterior tibia
Innervation of popliteus
- tibial nerve
Actions of popliteus
- internally rotate the flexed knee
- flex the knee
Quadriceps group
- 4 muscles (quad)
- vastus lateralis
- vastus medialis
- vastus intermedius
- rectus femoris
only rectus femoris flexes the hip
Attachments of quadriceps group
- proximal = vastus group on proximal femur and rectus femoris on ASIS
- distal = all are on anterior tibia via the patellofemoral tendon
Innervation of quadriceps group
- femoral nerve
Actions of quadriceps group
- extend the knee
- rectus femoris = flex the hip
Sartorius
- 2-joint muscle that attaches at an angle
- fusiform = long, thin muscle (which means lots of range of motion)
Attachments of sartorius
- proximal = ASIS
- distal = medial tibia
Innervation of sartorius
- femoral nerve
Actions of sartorius
- flex the hip
- extend the knee
- externally rotate the hip
Muscles of ankle dorsiflexor
- tibialis anterior
- extensor hallucis longus
- extensor digitorum longus
Attachments of tibialis anterior
- proximal = lateral tibia
- distal = medial cuneiform and 1st metatarsal (medial foot)
Innervation of tibialis anterior
- deep fibular nerve
Actions of tibialis anterior
- invert the foot
- dorsiflex the ankle
Attachments of extensor hallucis longus
- the extensor pollicis longus equivalent in the leg
- proximal = anterior fibula
- distal = phalanx of 1st toe (great toe)
Innervation of extensor hallucis longus
- deep fibular nerve
Actions of extensor hallucis longus
- extend the 1st toe (MT and IP joints)
- dorsiflex the ankle
- invert the foot (agonist with tibialis anterior)
Attachments of extensor digitorum longus
- proximal = lateral condyle of tibia and anterior fibula
- distal = middle and distal phalanges of toes 2-5
Innervation of extensor digitorum longus
- deep fibular nerve
Actions of extensor digitorum longus
- extend the 2nd through 5th toes (MT and IP joints)
- dorsiflex the ankle
- evert the foot (antagonists to tibialis anterior and extensor hallucis longus)
Muscles of superficial plantar flexors
- gastrocnemius
- soleus
- plantaris
Attachments of gastrocnemius
- two-joint muscle
- proximal = medial and lateral condyle of femur (posteriorly)
- distal = calcaneus via calcaneal tendon (AKA Achilles tendon)
Innervation of gastrocnemius
- tibial nerve
Actions of gastrocnemius
- flex the knee
- plantar flex the ankle
Attachments of soleus
- proximal = posterior, proximal tibia and fibula
- distal = calcaneus via calcaneal tendon (Achilles)
Innervation of soleus
- tibial nerve
Actions of soleus
- plantar flex the ankle
Attachments of plantaris
- the palmaris longus of the leg = still present in most people
- proximal = lateral femur
- distal = calcaneus via calcaneal (Achilles tendon)
Innervation of plantaris
- tibial nerve
Actions of plantaris
- weak plantar flexion of the ankle
- weak flexion of the knee
Muscles of deep plantar flexors
- tibialis posterior
- flexor hallucis longus
- flexor digitorum longus
Attachments of tibialis posterior
- does not cross the knee
- proximal = posterior tibia and fibular
- distal = tarsal bones and 2-4 metatarsals
Innervation of tibialis posterior
- tibial nerve
Actions of tibialis posterior
- invert the foot
- plantar flex the ankle
tibialis anterior and posterior in sagittal plane = antagonists
tibialis anterior and posterior in frontal plane = agonists
Attachments of flexor hallucis longus
- proximal = posterior fibula
- distal = distal phalanx of 1st toe
Innervation of flexor hallucis longus
- tibial nerve
Actions of flexor hallucis longus
- flex the 1st toe
- weak plantar flexion of the ankle
- invert the foot
extensor hallucis longus and flexor hallucis longus in sagittal plane = antagonists
extensor hallucis longus and flexor hallucis longus in frontal plane = agonists
Attachments of flexor digitorum longus
- proximal = posterior tibia
- distal = distal phalanges of digits 2-5 (no great toe)
Innervation of flexor digitorum longus
- tibial nerve
Actions of flexor digitorum longus
- flex 2nd-5th toes (MT and IP joints)
- weak plantar flexion of the ankle
- invert the foot
Lateral compartment of plantar flexors
- fibularis longus
- fibularis brevis
Attachments of fibularis longus and fibularis brevis
- proximal = fibula
- distal = 1st (longus) and 5th (brevis) MT
runs posteriorly to the lateral malleolus
often called peroneus muscles and perineal nerve in older textbooks
Innervation of fibularis longus and fibularis brevis
- superficial fibular nerve
Actions of fibularis longus and fibularis brevis
- evert the foot (much stronger than the action of plantar flexing the ankle)
- plantar flex the ankle (assist)
Pathways of nerves in the lower extremity
- not required to know the sensory compartment for lower extremity
- femoral nerve ends at the quad innervation (doesn’t go pass the knee)
- all the nerves in the knee (leg) are extension of the sciatic nerve, even the ones on the anterior side (deep fibular) and lateral side (superficial fibular)
Ex question = if sciatic nerve gets impacted, you cannot do anything below the knee
