Short Head of Biceps Femoris Muscle

Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA

SHORT HEAD OF BICEPS FEMORIS

SHORT HEAD OF BICEPS FEMORIS

Origin:
Femoral shaft from the middle 1/3rd of the Linea Aspera lateral to the supracondylar ridge of the femur.

Insertion :
It joins with the long head of the Biceps Femoris in the distal thigh and inserts at the fibular head.

Nerve Supply:
Common Peroneal nerve (L5,S1) which is a branch of the Sciatic nerve.

Branches of Sciatic nerve:

1. Common peroneal
2. Posterior tibial branch which innervates the Long head of the biceps femoris

Important facts:
Long head of the biceps femoris arises from the upper and medial part of the back of the ischial tuberosity.
Short Head of the biceps femoris is not part of the hamstrings as it does not originate from the ischial tuberosity.

Note :
1. It is the most posterior most structure inserted into the fibular head.
2. Structures attached to the fibular head from anterior to posterior

• Lateral collateral ligament
• Popliteo-fibular ligament
• Biceps femoris tendon

BEWARE!
Posterior to biceps femoris you will find the common peroneal nerve

Clinical application:
A high sciatic nerve lesion can mimic a common perineal nerve injury at the fibular head.
In both the condition, the patient will have foot drop but the EMG will show abnormalities in the short head of the biceps femoris muscle if the lesion is a high sciatic nerve palsy.

Action:
Flexes the knee joint and laterally rotates the knee (external rotation)

Nerve supply:
Common peroneal nerve (L5,S1)