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Biceps femoris




Biceps femoris
Biceps femoris
Biceps femoris - lateral

General information

  • This section is strictly limited to anatomy, you might be looking for clinical relevant information which is found under the clinical chapters -- muscles section, click here to go to that page


  • Superficial


  • Tuberositas ischiadicum (long-head)
  • Sacrotuberose ligament (long-head)
  • Laterale ridge of linea aspera (short-head)
  • Proximale 2/3 of linea supracondylare (short-head)
  • Lateral septum intermusculare (short-head)


  • Lateral side of the head of fibula
  • Lateral condyle of the tibia
  • Deep fascia of the lateral aspect of the calf

Main function

  • Knee
    • Flexion
  • Hip
    • Extension
  • Pelvis
    • Posterior tilt

Secondary function

  • Knee
    • Lateral rotation
  • Hip
    • Adduction
    • Lateral rotation

Nerve innervation

  • Segmental
    • L5-S2
  • Peripheral
    • Long-head from the nervus tibialis
    • Short-head from the nervus fibularis

Arterial supply

  • Inferior gluteal artery
  • Deep femoral artery
  • Obturator artery
  • Popliteal artery


  • Patient position: Prone
  • Place your own knee under the foot of the patient so that the patient has the knee in a light flexed position while lying down
  • Hold the heel of the patient's foot with your one hand and give resistance to the patient in the direction of extension of the knee while the patient is giving force towards flexion of the knee
  • Use the other hand to palpate distally and posterolaterally on the thigh of the patient and feel for contraction in the muscle
  • When you have palpated biceps femoris, you can follow the muscle up until it's insertion at the tuberositas ischiadicum

Strength test

  • Patient position: Prone
  • Fixate the patient's thigh down towards the bench with your one hand
  • Bend the patient's knee until 60°
  • Position the hip so that it is in a light lateral rotation
  • Position the knee so that it too is in a light lateral rotation
  • Give resistance posteriorly and distally on the calf of the patient, just proximal to the ankle
    • The pressure you are creating is in an extension direction of the knee so that the patient is giving force towards flexion of the knee
  • If the patient has weakness:
    • The patient may have problems maintaining the foot in a rotated position which is the start of the test
    • Weakness of the biceps femoris gives a tendency for lateral stability to be diminished
      • This leads to altered gait so that in some cases may look like the leg is curving out laterally
    • Observation of gait:
      • If all of the hamstring group is weak, there is a posibility that the knee will naturally hyperextend
      • In bilateral weakness
        • The pelvis will compensate by tilting anterioly so that the patient often has a lordosis of the lower back