Trendelenburg's Sign: How to Check for Gluteus Medius Weakness

Trendelenburg's Sign is a fundamental orthopedic test used by physiotherapists to assess the strength of the gluteus medius muscle, which is a key stabilizer of the hip and pelvis, especially during gait.

1. Purpose

The primary purpose is to **test for** weakness of the Gluteus Medius muscle on the stance (standing) leg. This muscle is crucial for stabilizing the pelvis and preventing it from "dropping" on the opposite side during single-leg stance or walking.

2. How to Perform

1. The patient is positioned in standing.
2. The examiner stands behind the patient to observe the iliac crests (the top of the pelvic bones).
3. The examiner instructs the patient to "Stand on one leg" by lifting the non-test leg off the ground (flexing the hip and knee).
4. The patient is asked to hold this position for 10-30 seconds.
5. The examiner observes what happens to the iliac crest on the lifted (non-stance) side.
6. The test is repeated on the other side for comparison.

3. Positive & Negative Sign

Positive Sign (Test is POSITIVE):
A positive test (indicating gluteus medius weakness) is:

• The pelvis on the lifted (non-stance) side drops down.
• This indicates weakness in the gluteus medius muscle on the stance (standing) side.

Negative Sign (Test is NEGATIVE):
A negative test (indicating a strong muscle) is:

• The pelvis on the lifted (non-stance) side remains level or rises slightly.
• This indicates the gluteus medius on the stance side is strong enough to stabilize the pelvis.