Flashcards in M: Posterior thigh and popliteal fossa Deck (28)
What does the femur articulate with?
Proximally with the acetabulum
Distally with the tibia
What is the linea aspera?
A pair of ridges that run longitudinally along the dorsal surface and form an attachment site for several muscles of the thigh
What is the fascia lata?
Deep fascia which surround the muscles of the thigh, the fascia lata also forms 3 intermuscular septa that attach to the linea aspera and divide the muscles of the thigh into 3 compartments
What are the 3 muscle compartments of the thigh?
1) Anterior extensor
2) Posterior flexor
3) Medial adductor
The posterior compartment contains the 3 hamstring muscles, what are they?
3) Biceps femoris (long head)
What is the common proximal attachment and nerve supply of the hamstrings?
Common proximal attachment: ischial tuberosity
Innervation: tibial division of sciatic nerve (L5, S1, S2)
What is the distal insertion of the biceps femoris?
Head of fibula
What is the distal insertion of the semitendinous muscle?
Medial surface of the proximal tibia
What is the distal insertion of the semimembranous muscle?
Medial and posterior surface of medial tibial condyle
Is the short head of biceps femoris considered part of the hamstring muscles, why?
Not considered part of the hamstrings, does not share the common proximal attachment and innervation of the hamstring muscles
What are the attachments and innervation of biceps femoris?
Origin = lateral line of linea aspera
Insertion = head of fibula
Innervation = common fibular division of the sciatic nerve
What are the functions of the hamstrings at the hip?
1) Extend the thigh at the hip joint
2) Rotate the hip joint medially and laterally
What are the functions of the hamstrings at the knee?
1) Flex the leg at the knee joint
2) Rotate the leg at the knee joint - both medially and laterally
Part of the adductor magus muscle is also considered as part of the hamstrings, why is this different?
Part of the medial compartment and not part of the posterior compartment of the thigh
What 2 parts is adductor magnus composed of?
1) Adductor part
2) Hamstring part
Adductor magnus has a dual nerve supply, what is it?
1) Adductor part - Obturator nerve (L2, L3, L4)
2) Hamstring part - Tibial division of the sciatic nerve (L2,L3,L4)
What are the proximal attachments of the 2 parts of adductor magnus muscle?
1) Adductor part - Ischiopubic ramus
2) Hamstring part - Ischial tuberosity
Why is the hamstring part of adductor magnus considered as part of the hamstrings?
Shares the common proximal attachment and nerve supply
What 2 nerves does the sciatic nerve split into at the back of the thigh and what is their course?
At a variable point at the back of the thigh the sciatic nerve divides into the common fibular (peroneal) and tibial nerves. The common fibular nerve deviates laterally and the tibial nerve continues in the midline, both entering the popliteal fossa
What is the popliteal fossa?
Diamond-shaped depression located on the posterior aspect of the knee
Which muscles form the borders of the popliteal fossa?
Superior laterally - biceps femoris
Superior medially - semimembranous and semitendinous
Inferior - medial and lateral head of gastrocnemius muscle
What structure forms the roof of the popliteal fossa?
Deep fascia which is continuous above with the fascia lata of the thigh and below with the deep fascia of the left
What structures form the floor of the popliteal fossa?
Capsule of knee joint and adjacent surfaces of the femur and tibia and more inferiorly the popliteus muscle
What sub-compartments is the posterior compartment of the leg divided into and how?
Divided into superficial and deep sub compartments by the transverse intermuscular septum
What 3 muscles are found within the superficial posterior compartment of the leg?
Which of the 3 muscles in the superficial posterior compartment of the leg function as a flexor of the knee aswell as a plantar flexor of the ankle joint?
Gastrocnemius and plantaris
What is meant by plantarflexion?
Flexion of the foot downwards towards the sole