Basic Anatomy of the Lower Limb Flashcards
Where do the lower limbs extend from?
The pelvis
What are the functions of the lower limbs?
Support body weight, locomotion, maintain balance
What are the six regions of the lower limbs?
Gluteal, femoral (thigh), knee, leg, ankle, foot
Where do nerves enter/exit the pelvis and perineum in the gluteal region?
Via the greater (for pelvis) and lesser (for perineum) sciatic foramen
What forms the greater and lesser sciatic foramen?
The sacrotuberous and sacrospinous ligaments
What makes up the superficial muscle groups of the gluteal region?
Gluteus maximus, gluteus medius, gluteus minimus, tensor fascia latae; extensors, abductors and medial rotators of thighs
What are the superficial muscle groups of the gluteal region innervated by?
Gluteus maximus = inferior gluteal
All others = superior gluteal
What is Trendelenburg’s gait?
Abnormal gait caused by weakness of abductor muscles of lower limbs, gluteus medius and gluteus maximus; caused by lesions of superior gluteal nerve
What makes up the deep muscle groups of the gluteal region?
Piriformis, obturator internus, gemelli, quadratus femoris; lateral rotators of thigh and hip stabilisers
What are the deep muscles of the gluteal region innervated by?
Nerves from the sacral plexus
What nerves are present in the gluteal region?
Sciatic nerves (L4-S3) Pudendal nerves (S2-S4) Posterior cutaneous nerve of the thigh (S1-S3)
Where does the sciatic nerve supply?
Posterior thigh, all leg and foot muscles and most of the skin via tibial and common fibular branches (largest nerve in body)
Where does the pudendal nerve supply?
Principal nerve of the perineum
Where does the posterior cutaneous nerve of the thigh supply?
Skin over posterior thigh, popliteal fossa, lateral perineum and upper medial thigh
Where does the sciatic nerve usually exit the spinal column?
Inferior to the piriformis
What is normally the most lateral structure exiting the greater sciatic foramen?
The sciatic nerve
What is the name of the artery that supplies the sciatic nerve?
Artery to the sciatic nerve
Does the sciatic nerve supply anything in the gluteal region?
No-passes down posterior to thigh
Where does the sciatic nerve separate, and what does it separate into?
Separates in distal thigh to tibial nerve (larger, medial) and the common fibular (smaller, lateral)
What are the boundaries of the femoral triangle?
Superior = inguinal ligament Medially = adductor longus Laterally = sartorius Floor = iliopsoas and pectineus Roof = deep fascia (fascia lata)
What are the contents of the femoral triangle?
Femoral nerve, femoral artery, femoral vein, lymphatics
What is compartment syndrome?
Fascia creates enclosed space, increased pressure causes swelling of tissue or increase in fluid, may be acute or chronic
What does compartment syndrome affect and how can it be relieved?
Can affect functions of muscles and nerves in that compartment; fasciotomy relives pressure in an emergency
What are the muscle compartments of the thigh?
Anterior, medial and posterior
What are the muscle compartments of the leg?
Anterior, posterior and lateral
What make up the anterior compartment of the thigh?
Flexors of thigh = pectineus, iliopsoas, sartorius
Extensors of leg = quadriceps femoris
What nerves supply the anterior compartment of the thigh?
The femoral nerve (L2-L4), also the psoas major
What make up the medial compartment of the thigh?
Adductors of thigh = adductor longus, adductor brevis, adductor magnus, gracilis, obturator externus
What nerves innervate the medial compartment of the thigh?
All innervated by the obturator nerve (L2-L4)
Hamstring part of adductor magnus innervated by tibial nerve
What make up the posterior compartment of the thigh?
Extensors of thigh and flexors of leg = semitendinosus, semimembranosus, biceps femoris
What nerves supply the posterior compartment of the thigh?
All innervated by the tibial division of sciatic nerve (L5, S1, S2)
Short head of biceps femoris innervated by common fibular division of the sciatic
What make up the anterior compartment of the leg?
Dorsiflexors of ankle and extensors of toes = tibialis anterior, extensor digitorium longus, extensor hallucis longus, fibularis tertius
What nerve supplies the anterior compartment of the leg?
The deep fibular nerve (L4, L5)
What make up the lateral compartment of the leg?
Evert foot and weakly plantarflex ankle = fibularis longus, fibularis brevis
What nerve innervates the lateral compartment of the leg?
Superficial fibular nerve (L5, S1, S2)
What make up the superficial group of the posterior compartment of the leg?
Plantarflexors of ankle = gastrocnemius, soleus, plantaris
What make up the deep group of the posterior compartment of the leg?
Flexors of toes, plantarflexors of ankle = popliteus, flexor hallucis longus, flexor digitorium longus, tibialis poterior
What nerve innervates both the superficial and the deep groups of the posterior compartment of the leg?
Tibial nerve (S1, S2)
What kind of joint is the hip joint?
Ball and socket = ball is head of femur, socket is acetabulum of hip
Synovial joint = within strong joint capsules, external and internal fibrous layers
What directions can the hip joint move in?
Multi-axial = flexion-extension, abduction-adduction, medial-lateral rotation, circumduction
What part of the hip joint forms the ligaments?
The thick part of the fibrous layer of the joint capsule
Where do the ligaments of the hip joint begin, and what is there function?
Spiral from pelvis to femur; strengthen the joint capsule
What are the ligaments of the hip joint?
Iliofemoral, pubofemoral, ischiofemoral
What is the name of the ligament that goes from the hip to the head of the femur?
The ligamentum teres
What vessels supply the hip joint?
Medial and lateral circumflex femoral arteries = usually from deep femoral artery, give off retinacular arteries
What vessel supplies the head of the femur?
A branch of the obturator, travels in ligament to head of femur
What kind of joint is the knee joint?
Hinge joint = 3 articulations (2 are femerotibial, one is femeropatellar)
Synovial joint = external fibrous layer ( not as strong as hip joint) and internal fibrous layer (extensions as bursae)
What is the main movement of the knee joint?
Flexion-extension ( some medial-lateral rotation can occur when knee is flexed)
What are the three types of ligament found in the knee?
Extracapsular, Intra-articular, Menisci
What are some examples of extra-capsular (outside capsule) ligaments of the knee?
Patellar ligament, lateral (fibular) collateral ligament, medial (tibial) collateral ligament
What are some examples of intra-articular (within joint) ligaments of the knee?
Anterior cruciate ligament (ACL), posterior cruciate ligament (PCL)
What are some features of the menisci of the knee?
Crescent shaped, fibrocartilage, medial and lateral
What gives an indicator of knee joint integrity?
Anterior/posterior drawer signs = if positive then the ACL/PCL is torn
Where is the popliteal fossa located?
Posterior to the knee
What are the boundaries of the popliteal fossa?
Superolaterally = biceps femoris Superomedially = semimembranosus Inferiorly = gastrocnemius Roof = popliteal fascia
What are the contents of the popliteal fossa?
Lots of fat, terminal small saphenous vein, popliteal vessels, tibial and common fibular nerves
What is the other name for the calcaneal tendon?
The achilles tendon
What are some features of the calcaneal tendon?
Thickest and strongest in body , about 15cm long, tendons to gastrocnemius and soleus together, attaches to calcaneal tuberosity of the calcaneus
What is the “ankle jerk” reflex?
Test of S1 and S2 nerve roots, normal result is plantarflexion
What are some features of the superficial lymphatics?
Follow saphenous vein, drain into superficial inguinal lymph nodes then external iliac lymph nodes
What are some features of the deep lymphatics?
Follow deep veins, popliteal lymph nodes to deep inguinal lymph nodes then external iliac lymph nodes
Where does the lymphatics flow to once it has reached the external iliac lymph nodes?
The common iliac lymph nodes (lumbar lymphatics)
Where does the femoral nerve (L2-4) supply?
Quadriceps femoris, sartorius, iliacus, pectineus
Where does the obturator nerve (L2-4) supply?
All of the medial compartment of thigh, all adductors (except hamstring part of magnus), gracilis
Where does the common fibular part of the sciatic nerve (L4-S2) supply?
Short head of biceps femoris
Where does the superior fibular branch of the common fibular nerve supply?
Muscles of the lateral compartment of leg (fibularis longus and brevis)
What compartments does the tibial part of the sciatic nerve (L4-S3) supply?
Muscles of posterior compartment of thigh, muscles of posterior compartment of leg, muscles of sole of foot
What muscles of the posterior compartment of the thigh does the tibial part of the sciatic nerve supply?
True hamstrings = long head of biceps femoris, semimembranosus, semitendinosus
What muscles of the posterior compartment of the leg does the tibial part of the sciatic nerve supply?
Gastrocnemius, soleus, plantaris, popliteus, tibialis posterior
What muscles of the sole of the foot does the tibial part of the sciatic nerve supply?
Flexors of digits (digitorium and hallucis longus), all intrinsic muscles of sole of foot (via medial and lateral plantar branches)
Where does the deep fibular branch of the common fibular nerve supply?
Muscles of anterior compartment of leg = tibialis anterior, extensor digitorium longus, extensor hallucis longus, fibularis tertus
Muscles of dorsum of foot = extensor digitorium brevis (EDB), extensor hallucis brevis (EHB)
What plexus of nerves supplies all other lower limb associated muscles (e.g gluteal/lateral rotators)
Branches of the lumbosacral plexus
What muscles make up the quadriceps?
Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius ( under rectus femoris)
Why is the short head of the biceps femoris not a true hamstring?
It doesn’t attach to the ischial tuberosity
