Lower Limb Anatomy Flashcards
What type of joint is the hip joint?
Synovial, capsule, ball-and-socket between the acetabulum and the femur head
What determines the stability of the hip joint?
- Acetabular depth
- Femur neck length and obliquity
- Capsular ligaments
- Muscles
Draw out the hip and upper thigh muscles (anterior compartment).
Refer to Notion.
Draw out the hip and upper thigh muscles (posterior compartment).
Refer to Notion.
What causes hip flexion?
- Psoas major + iliacus
- Pectineus + rectus femoris + sartorius
What causes hip extension?
- Gluteus maximus
- Hamstrings (long head of biceps femoris, semimembranosus, semitendinosus)
What causes (limited) medial hip rotation?
- Anterior fibers of gluteus medius and minimus
- Tensor fascia latae
What causes (limited) lateral hip rotation?
- Obturator internus and externus
- Piriformis
- Superior / Inferior gemellus
- Quadrator femoris
What causes hip abduction?
- Tensor fascia latae + sartorius
- Gluteus medius + minimus
What causes hip adduction?
- Adductors longus, brevis, magnus + gracilis + pectineus
What supplies blood to the head and neck of femur?
- Medial + Lateral Cx Femoral a.
- Obturator a.
- Superior / Inferior gluteal a., which form trochanteric cruciate anastomosis
What spinal nerve roots are responsible for inward movements of the hip (flexion, adduction, medial rotation?
L2 - L3
What spinal nerve roots are responsible for inward movements of the hip (extension, abduction, lateral rotation?
L4 - L5
Draw out the femur, labelled.
Refer to Notion.
Draw out the tibia and fibula, labelled.
Refer to Notion.
What type of joint is the knee joint?
Modified hinge joint; lateral and medial femorotibial condylar articulation + femoropatellar saddle-type articulation
What determines the stability of the knee joint?
- Depth of articular surfaces (not deep and very incongruent, thus making it weak)
- Muscles
- Ligaments
- Long axes of femur and tibia (face outwards, making it weak)
Where is the patella found?
Embedded in quadriceps tendon
Are the ACL and PCL located inside or outside the knee joint’s synovial capsule?
Outside; the capsule indents inwards to accommodate them.
What ligaments support the knee joint?
- ACruciateL, PCL, fibular CollateralL, tibial CL (aka lateral / medial CL)
- oblique popliteal ligament
- patellar ligament
- Iliotibial tract (when knee is flexed)
Describe the structure of the ACL.
Originates from anterior intercondylar area of tibia (just behind attachment point of medial meniscus), inserts onto the medial surface of lateral femoral condyle.
Poor blood supply.
Describe the structure of the PCL.
Originates from posterior intercondylar area of tibia (behind ACL), inserts onto the anterolateral surface of medial femoral condyle
Describe the function of the ACL.
- Prevents knee hyperextension
- Prevents posterior displacement of femur on tibia
Describe the function of the PCL.
Main stabilising factor of knee
- Prevents knee hyperflexion
- Prevents anterior displacement of femur on tibia (when on ground)
- Prevents posterior displacement of femur on tibia (when off ground)
Describe the structure of the knee menisci.
Medial meniscus is C-shaped and broader, and firmly attached to MCL.
Lateral meniscus is more circular, and more free-moving as it is not attached to LCL.
What causes knee flexion?
- Hamstrings
- Gastrocnemius
What causes knee extension?
- Quadriceps
What causes (limited) medial knee rotation?
- Semimembranosus + Semitendinosus
- Popliteus
What causes (limited) lateral knee rotation?
- Biceps femoris
What spinal nerve roots are responsible for knee flexion?
L5 - S2
What spinal nerve roots are responsible for knee extension?
L2 - L4
What spinal nerve roots are responsible for knee rotation?
L4 - S1
What determines the stability of the ankle joint?
- Congruency of articular surfaces
- Medial and Lateral ligaments (strong)
- Interosseus ligament of the inferior tibiofibular syndesmosis
- Muscles and tendons
What type of joint is the ankle joint?
Synovial hinge joint, between malleoli and lower end of tibia + body of talus
What causes ankle dorsiflexion?
- Tibalis anterior
- Extensor hallucis longus
- Extensor digitorum longus
- Fibularis tertius
What causes ankle plantarflexion?
- Tibalis posterior
- Flexor digitorum longus
- Gastrocnemius + Soleus
- Fibularis longus + Fibularis brevis
What spinal nerve roots are responsible for ankle dorsiflexion?
L4 - L5
What spinal nerve roots are responsible for ankle plantarflexion?
S1 - S2
Draw out and label the foot bones.
Refer to Notion.
What are the two foot joints?
- Subtalar Joint
- Transverse Talar Joint
Describe the subtalar joint.
Synovial, weak capsule. Allows for inversion and eversion of foot
Describe the transverse talar joint.
Compound joint, consisting of the talocalcaneonavicular + calcaneocuboid joints. They align transversely, allowing for surgical foot amputation.
What spinal nerve roots are responsible for ankle inversion?
L4 - L5
What spinal nerve roots are responsible for ankle eversion?
L5 - S1
What are the three arches of the foot?
Medial, Lateral, Transverse
What is the general structure of a foot arch?
- Keystone
- Intersegmental ties
- Tie beams
- Slings
Describe the structure of the medial foot arch.
Keystone - Talus
ISTs - Foot ligaments
Tie Beams - Medial plantar aponeurosis, Flexor hallucis brevis, Abductor hallucis
Slings - Anterior / Posterior tibialis, Flexor hallucis longus
Describe the structure of the lateral foot arch.
Keystone - Cuboid
ISTs - Foot ligaments
Tie Beams - Lateral plantar aponeurosis, Intrinsic muscle of the little toe
Slings - Fibularis longus / tertius / brevis
Describe the structure of the lateral foot arch.
Formed by bases of cuneiform, cuboid, and metatarsal bases
What is the function of the foot arches?
- Weight-bearing, shock absorber
- Protect neurovascular structures in sole
Medial - propulsion
Lateral - static support and weight transmission
Draw out and label the anatomy of the upper and lower leg anterior compartment muscles.
Refer to Notion.
Draw out and label the anatomy of the upper and lower leg posterior compartment muscles.
Refer to Notion.
What is present between the gluteus medius and gluteus minimus?
Trochanteric bursa
What does the tensor fascia latae do?
- Hip abduction
- Stabilises knee in extension / partial flexion
What opening is in the tensor fascia latae?
Saphenous opening (fossa ovalis), through which great saphenous vein + superficial inguinal LN pass through
What is the pes anserinus?
Tendons of sartorius, gracilis, and popliteus
What bursa is prone to bursitis
Pes anserinus bursa
What causes big toe movement?
- Flexor / Extensor hallucis longus
What causes toe movement?
- Flexor / Extensor digitorum longus
What causes foot eversion?
- Fibularis tertius / longus / brevis
What causes foot inversion?
- Tibalis anterior / posterior
What forms the calcaneal tendon?
Gastrocnemius, Soleus, Plantaris tendons
What is mainly responsible for ankle plantarflexion during knee extension?
- Gastrocnemius (cannot do plantarflexion in knee flexion)
What is mainly responsible for ankle plantarflexion during knee flexion?
- Soleus
What other function does soleus have?
Antigravity, via slow / sustained contractions
What does the popliteus do?
During knee flexion, it pulls lateral meniscus backward to prevent it from being crushed between tibial and femoral condyles
What can be found on the dorsum of the foot?
- Dorsalis pedis a.
- Dorsal venous arch
What is found on the sole of the foot?
Central aponeurosis, Medial / Lateral plantar fascia
What do the Central aponeurosis and Medial / Lateral plantar fascia do?
- Plantarflexion at MTP joints
- Dorsiflexion at DIP / PIP joints
Where do the sole nerves run in the foot?
Between 1st / 2nd / 3rd layer of muscles
Where do the sole arteries run in the foot?
Plantar arch (medial and lateral plantar a.) between 3rd / 4th layer
If the femoral artery is ligated, how can you supply blood to the lower leg?
Cruciate anastomosis between medial / lateral Cx a., first perforating femoral a., and inferior gluteal a.
Borders of femoral triangle?
Sartorius, inguinal ligament, adductor longus
Contents of femoral triangle + adductor canal?
femoral NAV (nerve, artery, vein), from lateral to medial
Borders of adductor canal?
Between vastus medialis and adductor longus, with overlying sartorius
Contents of popliteal fossa?
tibial n. > popliteal v. > popliteal a. > popliteal LN (lateral to medial)
Draw out the arterial supply of the leg.
Refer to Notion.
What are the arteries of the foot?
Dorsum - dorsalis pedis a. and branches
Sole - plantar arch (lateral and medial plantar a.)
Describe the venous drainage of the lower limb.
- Superficial veins (e.g. Great / Small saphenous v.)
- Perforating veins (valved communication between superficial and deep veins)
- Deep veins (e.g. venae comitantes; blood pumped via arterial pulsations and muscular contractions)
How do varicose veins occur?
Valvular insufficiency of perforating veins
What spinal roots supply sciatic nerve?
L4 - S3
Draw out the branches of the sciatic nerve.
Refer to Notion.
What spinal roots supply obturator nerve?
L2 - L4
Draw out the branches of the obturator nerve.
Refer to Notion.
What spinal roots supply femoral nerve?
L2 - L4
Draw out the branches of the femoral nerve.
Refer to Notion.
Draw out the dermatomal nerve supply / regions of the leg.
Refer to Notion.
Draw out the nerve supply for the hip muscles.
Refer to Notion.
Draw out the lymphatic nodes for the lower limb.
Refer to Notion.