M. Serratus posterior inferior

Origin

  • Th11-L2 through the Thoracolumbala fascia

Attachment

  • Costae 9-12

Innervation

  • Th9-Th12 Rr. Ventralis & Nn. Intercostalis

Plexa

Function

Unilateral function

  • Depression of costae 9-12
  • Contralateral rotation of thoracic and lumbar spine (Th11-L2)
  • Ipsilateral rotation of torso

Bilateral function

  • Accessory muscle on exhalation
  • Extension of trunk

Artery

Antagonist

  • M. Pectoralis major
  • M. Serratus anterior

Joints involved

  • Costovertebraljoints Th9-Th12
  • Intervertebraljoints Th11-L2

Descriptive text

The muscle is located below the M. Latissimus dorsi. It is thin and flat. It runs from the thoracolumbar junction obliquely upwards. The fiber direction goes obliquely upwards laterally to the lower ribs.

Exercise

Training tips

Therapist tips

  • Sometimes causes pain when forced to breathe
  • Raising and lowering the ribs can cause pain.

Treatment recommendations

  • Massage
  • Acupressure
  • Dry needling
  • Ledmanipulation
  • Stretch (home stretch and by therapist)
  • TENS
  • NMES
  • Cervical traction
  • Heating / Cooling

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