The Thigh & Knee Anatomy Flashcards
What surrounds the muscles of the thigh?
a layer of fascia called the fascia lata
What is formed from the fascia lata and how does it divide the muscles of the thigh?
fascia lata forms three intermuscular septa that run deep into the thigh and attach to the linea aspera
the three intermuscular septa divide the muscles of the thigh into 3 compartments:
anterior, medial and posterior
label the components/compartments of the thigh
What is the iliotibial tract and which muscles insert into it?
a thickening of the fascia lata on the lateral side of the thigh
the gluteus maximus and tensor fascia lata insert into the iliotibial tract
they help to stabilise the knee through the iliotibial tract
What is the pathway of the iliotibial tract and where does it insert?
it runs down the lateral aspect of the thigh, over the lateral part of the knee joint
it inserts onto the lateral aspect of the tibia
What are the muscles of the anterior thigh?
- quadriceps femoris (4 muscles)
- sartorius
- pectineus
- iliopsoas
label the muscles of the anterior thigh
What are the 4 muscles that compromise the quadriceps femoris?
- rectus femoris
- vastus lateralis
- vastus intermedius
- vastus medialis
What is the innervation and common insertion of the quadriceps muscles?
common insertion - patella
common innervation - femoral nerve (L2, L3, L4)
What is the common action of the quadriceps muscles?
What is different about rectus femoris and why?
they extend the leg at the knee joint
the rectus femoris also spans the hip joint so can flex the thigh at the hip joint
What is the origin of rectus femoris?
anterior inferior iliac spine (AIIS)
What is the origin of vastus lateralis?
greater trochanter and linea aspera
What is the origin of vastus intermedius?
anterior surface of femur
What is the origin of vastus medialis?
intertrochanteric line and linea aspera
What do all 4 quadriceps muscles converge on?
a common tendon called the quadriceps tendon
this runs over the knee joint onto the patella and becomes the patellar ligament
What is the role of the patellar ligament?
it connects the patella to the tibial tuberosity on the anterior tibia
How should the patient be positioned when testing the knee jerk reflex?
sat on a couch with their leg dangling
OR
their knee is flexed with the examiner supporting the weight of the leg with their arm
What are the steps involved in testing the knee jerk reflex?
- the examiner palpates for the patella and the tibial tuberosity
- they find the halfway point between them - this is the patellar ligament
- they tap the patellar ligament with a tendon hammer
What does the knee jerk reflex test for?
it tests the femoral nerve and the spinal nerves it contains (L2, L3, L4)
sometimes it is described as only testing L3 and L4 as the contribution from L2 is less
What will be seen in a normal knee jerk reflex?
the leg is extended once and then comes to rest
absence or decrease of this reflex is Westphal’s sign
What is the function of pectineus?
What is its innervation?
it adducts and flexes the thigh at the hip joint
it is innervated by the femoral nerve (L2, L3)
What is the insertion and origin of pectineus?
origin:
pectineal line and adjacent bone of the pelvis
insertion:
the oblique line, extending from the base of the lesser trochanter to the linea aspera
What are the origins and insertion of iliopsoas?
origins:
- psoas major - lumbar transverse processes of posterior abdominal wall
- iliacus - iliac fossa of posterior abdominal wall
insertion:
- lesser trochanter of femur
What is unusual about iliopsoas?
What is its function?
iliacus and psoas major are separate muscles that converge on a common tendon
iliopsoas is a primary flexor of the hip