Semimembranosus

Anatomy pictures

Referred pain pattern

Muscle Type

• Postural

Symptoms

• Pain or limping while walking
• Pain in buttocks, upper thigh or knee when sitting
• Sciatica or pseudo-sciatica
• Inability of complete range of motion in extension of knee
• 'Growing pains' in children
• Pelvic distortions and SI-joint dysfunction
• Tendinitis or bursitis at attachment

Muscular attachments

Videos

Short version

Detailed version

Alternative short version

Alternative detailed version

Important functions

• Gives support to the sacroiliac joint by giving a stabilizing influence via the sacrotuberous ligament

Notes of clinical importance

• Releasing or relaxing a tense Hamstrings might put an unstable sacroiliac joint at risk by removing the hamstrings' protective influence (the Hamstrings stabilizes the SIJ joint)
• The 4 major muscles that creates the stability for the SIJ joint is the Erector Spinae, Biceps Femoris, Latissimus dorsi and Gluteus Maximus

Myofascial lines

Dorsal line:

• Epicranial fascia
• Rectus capitis posterior major and minor
• Sacrolumbar fascia/erector spinae
• Sacrotuberous ligament
• Hamstrings
  • Biceps femoris
  • Semitendinosus
  • Semimembranosus
• Gastrocnemius and soleus
• Plantar fascia

Anatomy

Position

• Distal part is superficial
• The remaining part of the muscle lies deep to the semitendinosus

Origin

• Tuberositas ischiadicum
  • Proximal and lateral to the biceps femoris and semitendinosus tendons

Insertion

• Posteromedial part of the medial condyle of the tibia

Main function

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

Secondary function

• Knee
  • Medial rotation
• Hip
  • Medial rotation

Nerve innervation

• Segmental
  • L4-S2
• Peripheral
  • Nervus sciaticus
  • Nervus tibialis

Arterial supply

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