Anatomy of the lower limb Flashcards
What are the main regions of the lower limb?
Inguinal (A) / Gluteal (P)
Thigh (Femoral)
Knee (A) / Popliteal fossa (P)
Leg
Ankle
Foot
What are the main functions of the lower limb?
Supporting body weight
Locomotion
Maintenance of balance
Where is the gluteal region found?
Superiorly and posteriorly to the hip joint
What are the 4 superficial muscles of the gluteal region?
Gluteus maximus
Gluteus medius (Deeper)
Gluteus minimus (Deeper)
Tensor fascia latae
What are the functions of the superficial muscles of the gluteal region?
Extensors
Abductors
Medial rotators
Of the thigh
What nerve innervates the gluteus maximus?
Inferior gluteal
What nerve innervates the gluteus medius, gluteus minimus and tensor fascia latae?
Superior gluteal
What main group of nerves supplies the superficial muscles of the gluteal region?
Gluteal nerves
What clinical sign is caused by damage to the superior gluteal nerve?
Trendelenburg’s gait
What is Trendelenburg’s gait?
The gluteus medius and minimus help to raise the leg when weight is placed on the opposing leg
In Trendelenburg’s gait, the patient cannot properly raise the leg upon walking so the swing will not properly clear the ground, meaning the patient will lean to raise their leg as they swing it forward, causing a distinct waddle
What are the deep muscles of the gluteal region?
Piriformis
Obturator internus
Gemelli
Quadratus femoris
What are the functions of the deep muscles of the gluteal region?
Lateral rotators of the thigh
Stabilise the hip
What nerves innervate the deep muscles of the gluteal region?
Nerves from the sacral plexus
What are the 2 foramina via which nerves enter and exit the pelvis and perineum?
Greater sciatic foramen
Lesser sciatic foramen
What parts of the hip form the greater and lesser sciatic foramina?
Greater sciatic notch of the ileum
Sacrotuberous ligament
Sacrospinous ligament
Where do nerves passing through the greater sciatic foramen enter?
Pelvis
Where do nerves passing through the lesser sciatic foramen enter?
Perineum
Where does the sciatic nerve exit the spinal cord?
L4-S3
Describe the route of the sciatic nerve into the thigh
It is formed form the L4-S3 spinal nerves and passes through the greater sciatic foramen and medially to the femur, into the thigh
Via which foramen does the pudendal nerve pass?
Lesser sciatic foramen
What nerves form the posterior cutaneous nerve of the thigh?
S1 - S3
Describe the route of the posterior cutaneous nerve of the thigh
Formed from the S1-S3 spinal nerves
Runs along the sciatic nerve, through the greater sciatic foramen supplying the skin over the posterior thigh, popliteal fossa, lateral perineum and upper medial thigh
Why are injections into the gluteal region risky?
There is a high density of nerves
What are the boundaries of the 4 quadrants of the gluteal region?
Vertically down the midpoint of the iliac crest
Horizontally through the superior aspect of the greater trochanter
Into which quadrant should injections be administered to the gluteal region?
Upper, lateral quadrant
What is the largest nerve in the body?
Sciatic nerve
At what level does the sciatic nerve divide?
Distal thigh (Proximal thigh in 12% of people)
What are the 2 main branches of the sciatic nerve?
Tibial division - Larger, medial
Common fibular division - Smaller, lateral
What is generally supplied by the branches of the sciatic nerve?
Posterior thigh
All leg and foot muscles
Most of the skin
What makes up the femoral triangle (Prism)?
Inguinal ligament - Superiorly
Adductor longs - Medially
Sartorius - Laterally
Iliopsoas and pectineus - Floor
Fascia lata - Roof
What is contained in the femoral triangle (Order from lateral to medial)?
N erve
A rtery
V ein
l Y mphatics
(NAVY)
What structures are contained in the femoral sheath within the femoral triangle?
Artery and vein
What is the name of the deep fascia of the lower limb?
Fascia lata
What is formed by the fascia late at the lateral aspect of the thigh?
Iliotibial tract (Thickening of the fascia)
What is the deep fascia of the leg proper, known as?
Crural fascia
What are the thickened bands of fascia that compartmentalise muscle groups known as?
Inter-muscular septa
What do muscles within a muscular compartment have in common?
They will generally have similar actions and the same nerve supply
What are the benefits of inter-muscular septa?
they prevent expansion of muscle bellies, help in the venous pump system and control spread of infection or tumours
What occurs in compartment syndrome?
An increase in pressure within a muscle compartment caused by swelling of tissue or an increase in fluid (e.g. bleeding), which can begin to affect nervous signalling or muscle action
What is the emergency treatment option for compartment syndrome?
Emergency fasciotomy in which the fascia is cut to release pressure
What are the 3 compartments of the thigh?
Anterior compartment
Medial compartment
Posterior compartment
What are the 3 compartments of the leg proper?
Anterior compartment
Posterior compartment
Lateral compartment
What are the 2 types of muscle action found in the anterior compartment of the thigh?
Flexors of the thigh
Extensors of the leg
What are the 3 flexors of the thigh found in the anterior compartment of the thigh?
Pectineus
Iliopsoas
Sartorius
What muscle group makes up the extensors of the leg in the anterior compartment of the thigh?
Quadriceps femoris
What 4 muscles are part of the quadriceps femoris?
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius (Deep to rectus)