Biceps Femoris

Description

Illustration of the hamstring muscles

Diagram of the hamstring muscles. BF biceps femoris muscle, ST semitendinosus muscle, SM semimembranosus muscle, CT common tendon, CT(ft) free-tendon part of the common tendon. SN sciatic nerve, IT ischial tuberosity, FH fibular head, FT fat tissue in the space between the BF and ST/SMmuscles, (*) Popliteal vessels and nerve are interposed between the BF and ST/SM muscles

Name

• Bicep Femoris

General

• Long muscle of the posterior compartment of the thigh
• Works with the semitendinosus and semimembranosus to make up the hamstring muscles
• Consists of two heads, a long head and a short head
• Short head only contributes to knee flexion, sometimes not included in "hamstring"

Origin

• Long head: (inferomedial impression of) ischial tuberosity, sacrotuberous ligament
• Short head: linea aspera of femur (lateral lip), lateral supracondylar line of femur

Insertion

• Lateral aspect of head of fibula

Action

• Hip joint: thigh extension, thigh external rotation;
• Knee joint: leg flexion, leg external rotation; stabilizes pelvis

Innervation

• Long head: tibial division of sciatic nerve (L5-S2)
• Short head: common fibular division of sciatic nerve (L5-S2)

Vascular Supply

• Inferior gluteal artery
• Perforating arteries
• Popliteal artery

Anatomic Variations of the Short Head

• Short head can be congenitally absent
• May arise from alternative origin: ischial tuberosity, linea aspera, medial supracondylar ridge or other parts of femur
• May be attached to iliotibial band or to fibers of the lateral knee joint capsule

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Clinical Significance

Pathology

• Hamstring Strain
• Hamstring Tendonitis
• Ischial Tuberostiy Avulsion Fracture
  • Ischial apophyseal avulsion fractures account for between 1.4-4% of hamstring injuries

Procedural: Hip

• Hamstring Origin Percutaneous Needle Tenotomy
• Ischial Bursa Injection

Procedural: Knee

• Distal Biceps Femoris Injection
• Distal Semimembranosus Injection
• Pes Anserine Bursa Injection

Surgical

• Hamstring autografts are used in Anterior Cruciate Ligament reconstruction

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See Also

Hip

• Physical Exam Hip
• Hip Anatomy (Main)
• Hip Pain (Main)

Knee

• Physical Exam Knee
• Knee Anatomy (Main)
• Knee Pain (Main)

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