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)
What nerve innervates all muscles of the anterior compartment of the thigh, except the iliopsoas?
Femoral nerve (L2, L3, L4)
What spinal nerves innervate the iliopsoas?
L1, L2 and L3
What is the function of the muscles within the medial compartment of the thigh?
Adduction of the thigh
What are the 5 muscles of the medial compartment of the thigh?
Adductor longus
Adductor brevis
Adductor magnus
Gracillis
Obturator externus
What nerves innervate the muscles of the medial compartment of the thigh, except the hamstring part of the adductor magnus?
Obturator nerve (L2, L3, L4)
What nerve innervates the hamstring part of the adductor magnus?
Tibial nerve of the sciatic nerve
What are the 4 hamstring muscles?
Semiteninosus
Semimembranosus
Biceps femoris (Long head)
Part of adductor magnus
What are the functions of the muscles of the posterior compartment of the thigh?
Hamstring muscles (Expect adductor magnus part)
These allow for flexion of the knee and extension of the hip
What are the 3 hamstring muscles present in the posterior compartment of the thigh?
Semitendinosus
Semimembranosus
Biceps femoris
Why is the short head of the biceps femoris not regarded as being a true hamstring muscle?
It does not have the same attachment post to the ischial tuberosity as all the other muscles, it attaches to the femur, and therefore it cannot extend the thigh the way the other muscles do, it only flexes the knee
What nerve innervates all hamstring muscles (Short head of biceps not included)?
Tibial nerve of the sciatic nerve
What nerve innervates the short head of the biceps femoris?
Common fibular division of the sciatic nerve
What are the functions of the muscles of the anterior compartment of the leg proper?
Dorsiflexion of the ankle and extension of the toes
What are the 4 muscles of the anterior compartment of the leg proper?
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus (Big toes)
Fibularis tertius
What nerve innervates all of the muscles of the anterior compartment of the leg proper?
Deep fibular nerve (L4, L5) of the common fibular nerve of the sciatic nerve
What are the functions of the muscles within the lateral compartment of the leg proper?
Eversion of the foot and weak plantar flexion of the ankle
What are the muscles of the lateral compartment of the leg proper?
Fibularis longus
Fibularis brevis
What nerve innervates the muscles of the lateral compartment of the leg proper?
Superficial fibular nerve (L5, S1, S2) of the common fibular nerve of the sciatic nerve
What are the 2 groups of muscles within the posterior compartment of the leg proper?
Superficial group
Deep group
What is the function of the superficial group muscles of the posterior compartment of the leg proper?
Plantarflexion of the ankle
What are the 3 superficial group muscles of the posterior compartment of the leg proper?
Gastrocnemius (Medial and lateral heads)
Soleus
Plantaris
What nerve innervates the superficial group muscles of the posterior compartment of the leg proper?
Tibial nerve (S1, S2) of the sciatic nerve
What tendon forms from the tendons of the gastrocnemius and soleus?
Calcaneal tendon (Achilles tendon)
What muscle of the posterior compartment of the leg proper, does not everyone have?
Plantaris
What are the functions of the deep group of muscles of the posterior compartment of the leg proper?
Flexion of the toes and plantarflexion of the ankle
What are the 4 deep group muscles of the posterior compartment of the leg proper?
Popliteus
Flexor hallucis longus
Flexor digitoxin longum
Tibialis posterior
What nerve innervates the deep group muscles of the posterior compartment of the leg proper?
Tibial nerve of the sciatic nerve
What type of joint is the hip joint?
Ball and socket joint
What forms the ball of the hip joint?
Head of the femur
What forms the socket of the femur?
Acetabulum
What structure deepens the acetabulum?
Acetabular labrum, a fibrocartilage lip which extends from the bone
What are the forms of movement of the hip joint?
Flexion & extension
Abduction & adduction
Medial & lateral rotation
Circumduction
What are the 2 layers of the synovial hip joint?
External fibrous layer
Internal synovial membrane layer
What part of the hip joint is damaged during a “Hip fracture”?
Neck of femur
What forms from the external fibrous layer of the synovial cavity of the hip joint?
The hip joint ligaments
What are the 3 external ligaments supporting the hip joint?
Iliofemoral (Strongest)
Pubofemoral
Ischiofemoral (Weakest)
Describe the route of the ligaments supporting the hip joint
They form from the external fibrous layer of the joint capsule and spiral around the neck of the femur, attach to the intertrochanteric line (Between trochanters)
What is the ligament attaching the acetabulum to the head of femur called?
Ligamentum teres
What is contained in the ligament teres?
The artery to the head of femur
Describe the blood supply to the hip joint
The hip joint is mostly supplied by the medial and lateral circumflex femoral arteries, usually supplies by the deep femoral artery (Profunda femoris)
These circle the hip joint and give off reticular arteries, which pass deep to or through the legaments of the joint capsule
What artery supplies the artery to the head of the femur?
Obturator artery
What type of joint is the knee joint?
Hinge joint
how many articulations are present in the knee joint?
3
What are the 3 articulations of the knee joint?
2 between femur and tibia (Medial and lateral condyles) known as the femerotibial articulations
1 between the femur and patella, known as the femeropatellar articulation
What name is given to the articulations between the medial and lateral condyles of the femur and the tibia?
Femerotibial articulation
What name is given to the articulation between the femur and patellar?
Femeropatellar articulation
What are the main movements of the knee joint?
Main - Flexion & extension
Some - Medial & lateral rotation when knee is flexed
What is special about the internal membranous layer of the synovial cavity of the knee joint?
It contains extensions forming fluid filled sacs, known as bursae, which decrease friction during movement
What are the 2 groups of ligaments supporting the knee joint?
Extra-capsular
Intra-capsular
What are the main 3 extra-capsular ligaments of the knee?
Patellar ligament
Lateral (Fibular) collateral ligament
Medial (Tibial) collateral ligament
What forms the patellar ligament?
The patellar ligament is a continuation of the ligaments of the quadriceps femoris muscles, attaching first to the patellar before forming a newly named ligament
What are the main 2 intra-capsular ligaments?
Anterior cruciate ligament (ACL)
Posterior cruciate ligament (PCL)
What clinical sign will be positive in a ruptured ACL?
Anterior draw sign - Free tibia will move anteriorly under the fixed femur
What clinical sign will be positive in a ruptured PCL?
Posterior draw sign - Free tibia will move posteriorly under the fixed femur
What are the menisci of the knee joint and what is their function?
They are 2 crescents of fibrocartilage that deepen the knee joint and act as shock absorbers in the knee
What are the 2 menisci of the knee joint?
Lateral meniscus
Medial meniscus
What is the popliteal fossa?
This is a mostly fat filled compartment, superior to the knee joint
What are the 4 main borders of the popliteal fossa?
Superolaterally - Biceps femoris
Superomedially - Semimembranosus
Inferiorly - gastrocnemius (Both heads)
Covering (Roof) - popliteal fascia
What structures are contained in the popliteal fossa?
terminal end of small saphenous vein
Popliteal artery
Popliteal vein
Tibial nerve
Common fibular nerve
Which tendon is the thickest and strongest in the body?
Calcaneal tendon (Achilles tendon)
Where does the calcaneal tendon (Achilles) attach?
To the tuberosity of the calcaneus
What structure do the superficial lymphatics of the lower limb follow?
Saphenous veins
Where will superficial lymphatics following the great saphenous vein drain?
Superficial inguinal nodes ->
External iliac nodes
Where will superficial lymphatics following the small saphenous vein drain?
Popliteal lymph nodes ->
Deep lymphatics
Where do deep lymphatics drain?
Popliteal lymph nodes ->
Deep inguinal lymph nodes ->
External iliac lymph nodes ->
Common iliac lymph nodes
What 3 bones form the hip bones?
Ilium
Ischium
Pubis
What is the name of the cartilage at the joining of the 3 bones of the hip
Triradiate cartilage
At what age does the femoral head become fully ossified?
16 years old
How are quadrants formed on an x-ray of the hips?
A line is drawn vertically down the centre of the iliac crest and is drawn horizontally through the triradiate cartilage
The head of the femur should always be in the lower medial quadrant unless it is dislocated
