Psoas major muscle

Organization and role

It works with the iliacus as part of the iliopsoas complex. Its proximity to the lumbar plexus matters in some assessments of groin or anterior thigh pain.

Clinical relevance and investigation

Pain on stretching does not prove a shortened psoas. Pain with fever, anticoagulation or neurological deficit may require investigation for abscess or hematoma.

Points to consider

Trunk and neck muscles contribute to different tasks depending on position and load. Local pain does not prove that one muscle is the sole cause. Assessment also considers strength, endurance, movement and the demands of usual activities.

Role of TAGMED care

At TAGMED, assessment aims to understand symptoms, history and functional limitations. Manual care and osteopathy, motorized spinal decompression, laser and shockwave have different indications. The term described in this entry is not enough to select any of these modalities. Their relevance, limitations and possible contraindications should be discussed in relation to diagnosis and individual goals.

Related concepts and distinctions

These concepts belong to the same field, but are not synonyms.

• Quadratus lumborum muscle — Deep posterior abdominal wall muscle linking the pelvis, lumbar transverse processes and twelfth rib.
• Transversus abdominis muscle — Deep abdominal wall muscle with mainly transverse fibers contributing to abdominal pressure control and trunk function.
• Erector spinae muscles — Longitudinal back muscle group including iliocostalis, longissimus and spinalis, involved in trunk support and extension.

Medical references

1. OpenStax, Rice University. Anatomy and Physiology 2e — Axial Muscles of the Head, Neck, and Back.
2. Radiological Society of North America. RadLex Radiology Lexicon — terminology resource.

References document the topic; their inclusion does not imply endorsement of TAGMED services by those organizations.