Lower Limb - Muscle Groups Flashcards
What is the deep fascia of the thigh called?
Fascia lata.
What does the fascia lata enclose?
Tensor fascia lata (TFL) and gluteus maximus.
What is the thickened lateral portion of the fascia lata?
Iliotibial (IT) tract.
What is the cribriform fascia?
Fascia over the saphenous opening, where the great saphenous vein passes.
What is the deep fascia of the leg called?
Crural fascia.
What does the crural fascia thicken to form at the ankle?
Extensor retinacula.
What is the role of fascial compartments?
Support muscle contraction, enhance venous return, but may raise pressure in closed space.
What is a clinical emergency involving increased pressure in fascial compartments?
Compartment syndrome
What is the late sign of compartment syndrome?
Absent pulse — amputation may be needed.
What are the muscles in the anterior thigh compartment?
Quadriceps femoris (rectus femoris, vastus medialis, intermedius, lateralis), sartorius, and pectineus.
What nerve supplies the anterior thigh?
Femoral nerve (L2–L4).
What is the main function of the anterior thigh muscles?
Knee extension.
What are the medial thigh muscles?
Adductors (longus, brevis, magnus), gracilis, and obturator externus.
What nerve innervates the medial thigh?
Obturator nerve (L2–L4).
What is the main action of the medial thigh compartment?
Hip adduction.
What are the posterior thigh muscles?
Semitendinosus, semimembranosus, biceps femoris, and part of adductor magnus.
What nerve supplies most posterior thigh muscles?
Tibial division of the sciatic nerve (L4–S3).
What are the functions of posterior thigh muscles?
Hip extension, knee flexion.
What are the boundaries of the femoral triangle?
Inguinal ligament, sartorius (lateral), adductor longus (medial).
What forms the floor of the femoral triangle?
Pectineus, iliopsoas, and adductor longus.
What are the contents of the femoral triangle (lateral to medial)?
Femoral nerve, artery, vein, canal, deep inguinal lymph nodes (NAVeL).
What are the contents of the adductor canal?
Femoral artery, femoral vein, saphenous nerve.
Where does the femoral artery become the popliteal artery?
After passing through the adductor hiatus.
What muscles make up the gluteal region?
Gluteus maximus, medius, minimus, piriformis, obturator internus, gemelli, quadratus femoris, TFL.
What nerves supply the gluteal muscles?
Superior/inferior gluteal nerves, nerves to OI, QF, and piriformis.
What is the safe site for IM injections in the gluteal region?
Upper lateral quadrant.
What muscles are in the anterior leg compartment?
Tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius.
What nerve and artery supply the anterior leg?
Deep fibular nerve and anterior tibial artery.
What is the primary function of the anterior leg compartment?
Dorsiflexion of the ankle.
What muscles are in the lateral leg compartment?
Fibularis longus and brevis.
What nerve supplies the lateral compartment?
Superficial fibular nerve.
What is the function of lateral compartment muscles?
Ankle eversion.
What is the primary nerve supply to the posterior leg?
Tibial nerve.
What is the main action of the posterior leg muscles?
Plantarflexion.
What artery supplies the posterior compartment?
Posterior tibial artery.
What are the boundaries of the popliteal fossa?
- Sup/lat: Biceps femoris
- Sup/med: Semitendinosus & semimembranosus
- Inf/lat: Lateral head of gastrocnemius & plantaris
- Inf/med: Medial head of gastrocnemius
What are the contents of the popliteal fossa?
Popliteal artery and vein, tibial nerve, small saphenous vein.
What spinal roots form the femoral nerve?
L2–L4.
What spinal roots form the sciatic nerve?
L4–S3.
What does the obturator nerve innervate?
Medial thigh muscles.
Where does the obturator nerve enter the thigh?
Through the obturator foramen.
Which spinal roots are responsible for hip flexion?
L2–L3.
Which spinal roots are responsible for knee extension?
L3–L4.
What are the motor effects of femoral nerve injury?
Weak knee extension, reduced hip flexion.
What sensory areas are affected in femoral neuropathy?
Anterior/medial thigh and medial leg.
What are the motor deficits in sciatic nerve injury?
Weak knee flexion, total loss of distal leg and foot movements.
What sensory deficits occur in sciatic neuropathy?
Posterior thigh and entire lower leg/foot.
Function of anterior thigh muscles?
Knee extension.
Main function of medial thigh muscles?
Hip adduction.
Function of posterior thigh muscles?
Hip extension and knee flexion.
Action of anterior leg muscles?
Dorsiflexion.
Action of lateral compartment?
Ankle eversion.
Action of posterior compartment muscles?
Plantarflexion.
What causes compartment syndrome?
Limb trauma, bleeding, compression, burns.
Classic signs of compartment syndrome (6 P’s)?
Pain, paresthesia, paresis, pink color, pulse present, pressure.
Hip flexion myotome?
L2–L3
Hip extension myotome?
L4–L5
Knee extension myotome?
L3–L4
Knee flexion myotome?
L5–S1
Ankle dorsiflexion myotome?
L4–L5
Ankle plantarflexion myotome?
S1–S2
Ankle inversion myotome?
L4–L5
Ankle eversion myotome?
L5–S1
Two major nerves of the lumbar plexus?
Femoral and obturator nerves (L2–L4).
What is the origin of the femoral nerve?
Posterior divisions of L2–L4.
What is the origin of the obturator nerve?
Anterior divisions of L2–L4.
What is the largest nerve from the sacral plexus?
Sciatic nerve.
What are the branches of the sciatic nerve?
Tibial and common fibular nerves.
What does the common fibular nerve supply?
Anterior and lateral compartments of the leg.
What does the tibial nerve supply?
Posterior compartment of the leg and foot.
Sensory loss from sciatic nerve damage?
Posterior thigh and entire lower leg/foot.
What motor functions are affected in sciatic nerve damage?
Knee flexion, all movements below the knee.
Why is the upper lateral quadrant used for injections?
Avoids sciatic and superior gluteal nerves.
