The posterior compartment of the thigh contains the hamstring muscles (biceps femoris, semitendinosus, semimembranosus, and part of the adductor magnus), which are supplied by branches from the sciatic nerve. It also contains cutaneous nerves that innervate the skin (medial, posterior, and lateral cutaneous nerves) and veins that drain into the great and small saphenous veins. The blood supply comes from branches of the profunda femoris artery and drains into the profunda femoris vein.

1. Posterior Compartment of the
Thigh
Dr. Mohammed Mahmoud Mosaed

2. Posterior Compartment of the Thigh
Cutaneous innervations
The medial cutaneous nerve
of the thigh on the medial
side
Posterior cutaneous nerve of
the thigh on the middle
Lateral cutaneous nerve of
the thigh on the lateral
side

3. Superficial Veins
■ Many small veins curve around the medial and
lateral aspects of the thigh drain into the
great saphenous vein.
■ Superficial veins from the lower part of the
back of the thigh join the small saphenous
vein in the popliteal fossa.
Lymph Vessels
■ Lymph from the skin and superficial fascia on
the back of the thigh drains upward and
forward into the vertical group of superficial
inguinal lymph nodes

4. Contents of the Posterior
Compartment of the Thigh
■ Muscles (hamstring muscles):
Biceps femoris, semitendinosus,
semimembranosus, and ischial part of the
adductor magnus
■ Blood supply:
Branches of the profunda femoris artery
■ Nerve supply: Sciatic nerve

5. Hamstring Muscles
Biceps femoris.
Semitendinosus.
Semimembranosus
Ischial part of
Adductor magnus.

6. Biceps Femoris
Origin:
Long head: lower medial part of
the upper area of the ischial
tuberosity.
Short head: lower part of the
linea aspera and lateral supra-
condylar ridge of femur.
Insertion:
The head of the fibula (the styloid
process of the fibula).
Nerve Supply: Sciatic nerve.
Action: Flexion and lateral
rotation of the leg.
Long head extends the thigh.

8. Semitendinosus
Origin:
Lower medial part of the upper area of the
ischial tuberosity with long head of biceps.
Insertion:
Upper part of the medial surface of the
shaft of the tibia behind the sartorius and
gracilis.
Nerve Supply: Sciatic nerve.
Action:
Flexion and medial rotation of the leg.
Extension of the thigh.

9. Semimembranosus
Origin:
Upper lateral part of the upper area of the ischial
tuberosity.
Insertion:
Posteromedial surface of the medial condyle of
the tibia.
Nerve Supply:
Sciatic nerve.
Action:
Flexion and medial rotation of the leg.
Extension of the thigh.

11. Ischial part of the adductor Magnus
Origin:
from the lateral part of
the lower area of the
ischial tuberosity.
Insertion:
Adductor tubercle of the
femur.
Nerve Supply:
Sciatic nerve.
Action:
Extension of the thigh.

12. Blood Supply
■ The four perforating branches of the
profunda femoris artery provide a rich
blood supply to the posterior
compartment of the thigh.
■ The profunda femoris vein drains the
greater part of the blood from the
compartment.

13. Nerve Supply
■ Sciatic Nerve
■ The sciatic nerve, a branch of the sacral plexus (L4 and 5; S1,
2, and 3), leaves the gluteal region as it descends in the
midline of the thigh.
■ In the lower third of the thigh it ends by dividing into the tibial
and common peroneal nerves
■ It gives muscular branches to the long head of the biceps
femoris, the semitendinosus, the semimembranosus, and the
hamstring part of the adductor magnus. These branches arise
from the tibial component of the sciatic nerve and run medially
to supply the muscles
■ The short head of biceps femoris supplied by branches arises
from the common peroneal nerve