Trendelenburg sign

Purpose

• Test for neurological insufficiency of the gluteus medius and gluteus minimus muscles, which are innervated by the superior gluteal nerve

Examination

• The patient is asked to stand on one leg.

Interpretation

• Negative Trendelenburg sign (physiological): The pelvis remains level as it is stabilized by the gluteus medius and minimus.
• Positive Trendelenburg sign (pathological): Because of insufficiency of the gluteus medius and minimus on the side of the standing leg, the pelvis drops towards the contralateral, unimpaired side.
• Duchenne sign: The torso tilts toward the contralateral side, compensating the pelvic drop on the unimpaired side.
• Duchenne limp: The Duchenne sign, which frequently occurs bilaterally, results in a compensatory to‑and‑from movement of the torso during walking.

Causes

• Iatrogenic Nerve Injury:
  • Posterior/lateral surgical approach to Total Hip Arthroplasty (THA).
  • Intramuscular (IM) injections in the dorsogluteal region (safe zone: anterolateral / superolateral quadrant).
• Spine & Neurologic Disorders:
  • L5 radiculopathy (herniated nucleus pulposus, lumbar spinal stenosis).
  • Poliomyelitis, ALS, Guillain-Barré syndrome (GBS).
• Musculoskeletal & Structural Disorders:
  • Chronic gluteus medius/minimus tendon tear or severe tendinopathy.
  • Developmental Dysplasia of the Hip (DDH).
  • Slipped Capital Femoral Epiphysis (SCFE).
  • Severe hip osteoarthritis (OA), avascular necrosis (AVN), or femoral neck nonunion.
• Myopathies: Duchenne/Becker muscular dystrophy, inflammatory myositis (polymyositis/dermatomyositis).