A positive psoas sign — increased abdominal pain when the patient moves the leg against resistance — indicates direct or reflexive irritation of the psoas muscles. It is typically associated with appendicitis but may also occur with localized retroperitoneal abscesses. The sign should be elicited after completion of a full abdominal examination to avoid false positives.

Emergency interventions

• If positive psoas sign is elicited in a patient with abdominal pain, suspect appendicitis.

• Check vital signs and prepare the patient for surgery:

  • Explain the procedure.

  • Restrict food and fluids.

  • Withhold analgesics that can mask symptoms.

  • Administer IV fluids to prevent dehydration.

  • Avoid cathartics or enemas, which may precipitate rupture.

• Assess for Rovsing’s sign: palpation of left lower quadrant producing right lower quadrant pain indicates peritoneal irritation.

History and Physical Examination

Symptom assessment

• Onset, duration, intensity, and localization of abdominal or lower back pain.

• History of previous similar episodes.

• Associated symptoms: nausea, vomiting, anorexia, fever.

Medical history

• Recent infection or trauma.

• Drug history.

• Pre-existing conditions: sickle cell disease, immunosuppression.

Physical examination

• Inspect and palpate the abdomen: rigidity, tenderness, rebound.

• Evaluate lower back and hip mobility.

• Vital signs for fever, tachycardia, or hypotension.

• Pediatric adaptation: have child raise head while applying gentle pressure to forehead; right lower quadrant pain indicates appendicitis.

Medical Causes

Special considerations

• Monitor for complications: peritonitis, extension along fascial planes.

• Promote patient comfort: assist with position changes (flexion of leg while lying down or sitting upright).

• Prepare for diagnostic tests: electrolyte studies, abdominal X-rays, imaging if abscess suspected.

Examination Tip: Eliciting a Psoas sign

• Supine method: Patient flexes leg against examiner’s hand; increased pain indicates positive sign.

• Side-lying method:

  • Turn patient on right side → flex left leg against resistance → test left psoas.

  • Turn patient on left side → flex right leg against resistance → test right psoas.

Pediatric pointers

• Elicit using head lift with gentle pressure; right lower quadrant pain indicates appendicitis.

• Monitor for behavioral changes: irritability, refusal to walk, or draw-up legs.

Geriatric pointers

• Peritoneal and psoas signs may be diminished or absent.

• Differentiate pain from musculoskeletal or degenerative joint conditions.

Patient counseling

• Explain underlying cause and treatment plan.

• Educate on signs requiring immediate attention (sudden severe pain, vomiting, fever).

• Teach use of pain rating scales for accurate reporting.

References

• Berkowitz, C. D. (2012). Berkowitz’s Pediatrics: A Primary Care Approach (4th ed.). USA: American Academy of Pediatrics.

• Buttaro, T. M., Tybulski, J., Bailey, P. P., & Sandberg-Cook, J. (2008). Primary Care: A Collaborative Practice (pp. 444–447). St. Louis, MO: Mosby Elsevier.

• Colyar, M. R. (2003). Well-Child Assessment for Primary Care Providers. Philadelphia, PA: F.A. Davis.

• Lehne, R. A. (2010). Pharmacology for Nursing Care (7th ed.). St. Louis, MO: Saunders Elsevier.

• Sommers, M. S., & Brunner, L. S. (2012). Pocket Diseases. Philadelphia, PA: F.A. Davis.