2.6.3. ANAT LAB - Anterior and Lateral Leg Dorsum Foot Flashcards
In the lower leg what bone supports the weight of the body?
Tibia
What is the fibula’s primary purpose?
Muscle attachment and stabilization during standing and locomotion It supports essentially no weight
What are the three anatomical compartments in the leg?
Anterior, lateral, and posterior
What nerve supplies the muscles of the anterior compartment?
Deep fibular (peroneal) nerve
What are the subdivisions of the posterior compartment?
Superficial and deep
What are the muscles of the anterior compartment?
Tibialis anterior (TA) Extensor digitorum longus (EDL) Extensor hallucis longus (EHL) Fibularis tertius
What artery is important in the anterior compartment?
Anterior tibial artery (a branch of the popliteal) supplies the anterior compartment of the leg and the dorsum of the foot
What does the anterior tibial artery become?
Dorsalis pedis artery (after it reaches the foot)
What is clinically important about the extensor digitorum brevis?
Contusion and tearing of the muscle fibers and associated blood vessels result in a hematoma in extensor digitorum brevis, producing edema anteromedial to the lateral malleolus Most people who have not seen this inflamed muscle assume they have a severely sprained ankle
What does the superficial fibular nerve innervate?
Muscles of the lateral compartment of the leg, which are essentially involved in eversion of the foot
What does the deep fibular nerve innervate?
Muscles of the anterior compartment of the leg and muscles on the dorsum of the foot These muscles are essentially dorsiflexors of the foot at the ankle and extensors of the toes
What is the most commonly injured nerve of the lower limb
The COMMON fibular nerve (vulnerable to compression injury, usually from direct trauma) where it wraps around the head of the fibula
What do patients present with when they have injured their common fibular nerve?
Footdrop (inability to dorsiflex at the ankle) and an inability to evert the foot
Which arteries are involved in the anastomosis at the ankle?
Malleolar, tarsal, and arcuate arteries
Posterior tibial pulse
Felt b/w the medial malleolus and the calcaneal tendon
Dorsalis pedis artery
A continuation of the anterior tibial artery Palpated on the dorsum of the foot just lateral to the tendon of the extensor hallucis longus as it emerges from the extensor retinaculum
Path of the posterior tibial artery
A continuation of the popliteal artery. Below the knee, it gives rise to the fibular (peroneal) artery, which courses deep to the flexor hallucis longus muscles. As the posterior tibial artery passes inferiorly to the medial malleolus and enters the sole of the foot, it divides into medial and lateral plantar arteries
What nerve accompanies the posterior tibial artery along most of its course?
The tibial nerve
What is the Q angle?
The angle created by the femur (normally diagonal) and the tibia (normally vertical) Assessed by drawing a line from the ASIS to the middle of the patella and extrapolating a second (vertical) line passing through the middle of the patella and tibial tuberosity
Is the Q angle normally wider in males or females?
Females because they have a wider pelves
What is genu varum?
Q-angle is abnormally small Bowleg
What happens because of genu varum?
Unequal weight bearing results in arthrosis (destruction of knee cartilage), and an overstressed fibular collateral ligament
What is genu valgum?
Q-angle is large (lateral angulation of the leg in relation to the thigh) Knock-knee
What happens because of genu valgum?
Excess stress and degeneration of the lateral structures of the knee joint
What are the medial and lateral tibial plateaus?
Clinical terms that refer to the cartilage-capped medial and lateral condyles
Where is a Tibial fracture most common?
The tibia is narrowest at the junction of its middle and inferior thirds (most frequent site of a fracture) This area also has the poorest blood supply
What type of fracture is most commonly seen in the tibia?
Because the anterior surface is subcutaneous, a compound fracture is typically seen
Where does a Fibular fracture commonly occur?
Fibular fractures commonly occur 2-6 cm proximal to the distal end of the lateral malleolus and are associated with fracture-dislocations of the ankle join
Talk about the etiology of an Epiphyseal plate fracture and who tends to get them most
Epiphysis dislocations commonly occur in children 10-17 years old. The epiphysis of the femoral head slips away from the femoral neck because of a weakened epiphyseal plate. This is caused by acute trauma or repetitive microtrauma.
Tendons vs. Ligaments
Tendons attach muscles to bones Ligaments attach bone to bone
Muscles of the lateral compartment?
Fibularis brevis (FB) Fibularis longis (FB)
Muscles of the posterior compartment?
Flexor hallucis longus (FHL) Soleus (SOL) Plantaris (P) Tibialis posterior (TP) Flexor digitorum longus (FDL)
What is compartment syndrome?
Compartment syndrome is a serious condition that involves increased pressure in a muscle compartment. It can lead to muscle and nerve damage and problems with blood flow.
Describe location of the Fibular artery
Largest branch of the tibial artery and arises inferior to the distal border of the popliteus and the tendinous arch of the soleus Descends obliquely toward the fibula and passes along the medial side usually with the flexor hallucis longus. It branches to the nutrient artery of the fibula. Distally, it branches into the terminal lateral malleolar and calcaneal branches
Tibial nerve - Where is it and what does it innervate?
This is the larger of two terminal branches of the sciatic nerve. It runs vertically through the popliteal fossa with the popliteal artery passing through the heads of the gastrocnemius. It supplies all muscles in the posterior compartment of the leg
What happens to the tibial nerve at the ankle?
At the ankle, the nerve lies between the FHL and FDL. It then divides into the medial and lateral plantar nerves inferior and posterior to the medial malleolus.
