Semimembranosus

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

• Semimembranosus

General

• Muscle of the posterior compartment of the thigh
• Works with semitendinosus, biceps femoris to form the hamstrings

Origin

• Superolateral impression of ischial tuberosity

Insertion

• Medial condyle of tibia

Actions

• Hip joint: thigh extension and internal rotation
• Knee joint: flexion and internal rotation of the leg
• Stabilizes pelvis

Innervation

• Tibial division of sciatic nerve (L5 – S2)

Vascular Supply

• Perforating branches
  • Femoral artery
  • Popliteal artery

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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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