The muscles of the anterior thigh.
Most of the muscles of the anterior thigh are devoted to movement at the knee, or movement
of the leg.
The anterior thigh is made up of a very large muscle group known as the quadriceps group
of muscles.
As the name implies, quad means four.
The quadriceps has four heads, or four different muscle bellies.
Running straight down the front of the thigh we have the rectus femoris muscle.
It will insert via the patellar tendon, past the patella, into the tibial tuberosity as
the patellar ligament.
This is one of the muscles of the quadriceps femoris.
The rectus femoris.
Keep in mind the thigh is known as the femoral region.
Rectus means straight.
So the straight muscle over the femoral region is the rectus femoris.
To the medial side of the rectus femoris we will see the vastus medialis muscle.
It also joins to pass through the patellar tendon and down to the tibial tuberosity.
On the lateral aspect of rectus femoris we see the vastus lateralis, also joining through
the patellar tendon and patellar ligament into the tibial tuberosity.
And if we remove the rectus femoris muscle we see immediately deep to it, the vastus
intermedius muscle.
The fourth of our quadriceps group of muscles.
Also joining the patellar tendon through the patella and patellar ligament to the tibial
tuberosity.
These muscles together, the rectus femoris, vastus lateralis, vastus medialis, and vastus
intermedius form the quadriceps group of muscles.
They all function as extensors at the knee.
Now rectus femoris also has one other function.
Because its origin is off of the pelvis it also functions to help flex at the hip.
Another muscle of the anterior thigh which comes from our anterior superior iliac spine
and crosses from lateral, over the front of the thigh, to medial, to actually pass posterior
to the knee joint to insert on the tibia, is known as the sartorius muscle.
The sartorius muscle.
A long strap like muscle.
For those of you in the upper level anatomy classes you will learn that the sartorius
muscle inserts with two other muscles into the top of the tibia via something known as
the pes ancerinus tendon.
The pes ancerinus tendon.
The last muscle of the anterior thigh also comes from the anterior superior iliac spine.
It is known as the tensor fasciae latae muscle.
The tensor fasciae latae muscle leaves the anterior superior iliac spine and runs in
most of us for about 6 to 8 inches before it becomes a tendinous band of connective
tissue which runs down the lateral aspect of the thigh.
This is known as the iliotibial tract.
Some books call it the iliotibial band.
Tensor fasciae latae inserts into that iliotibial band, which passes posterior to the knee joint
and then inserts in the anterior lateral aspect of the tibia.
Recall that the gluteus maximus inserted into the gluteal tuberosity of the femur, but also
into the iliotibial band as well.
So the muscles of the anterior thigh to recap, sartorius, a long strap muscle.
Tensor fasciae latae to the lateral side.
And then in the middle, the quadriceps group.
The rectus femoris, the vastus medialis, vastus lateralis, and deep to the rectus femoris,
the vastus intermedius.
Vastus intermedius.
Those are the muscles of the anterior compartment of the thigh.