Trendelenburg’s Test: How to Perform It, What a Positive Result Means, and Common Causes
The Trendelenburg test is a quick, hands-on orthopedic and physical therapy screen. It checks how well the hip abductor muscles, mainly the gluteus medius and gluteus minimus, stabilize the pelvis when you stand on one leg. Below is how the test is performed, how to read the result, and what a positive finding can point to.
What Is the Trendelenburg’s Test Used For?
The test is mainly used to identify weakness of the hip abductors. A positive Trendelenburg sign usually indicates weakness in the hip abductor muscles, which consist of the gluteus medius and gluteus minimus. Clinicians also use it as part of a wider assessment of mechanical, neurological, or spinal problems, including congenital hip dislocation and hip subluxation. It was first described in 1897 to identify hip abductor weakness in people with congenital dislocation of the hip and progressive muscular atrophy.
How to Perform the Trendelenburg’s Test
- The patient stands on one leg for about 30 seconds without leaning to one side.
- If balance is a concern, the patient may lightly hold onto a stable object for safety.
- The examiner watches the pelvis from behind to see whether it stays level during the single-leg stance.
- The test is repeated on the opposite leg so both sides can be compared.
The side being tested is the stance leg, the one the patient is standing on.
What Is a Positive Trendelenburg’s Test?
A positive result means the pelvis drops toward the unsupported side while the patient bears weight on one leg. The hip abductors of the stance leg are not holding the pelvis level. A negative result occurs when the pelvis on the opposite side rises, while a positive result occurs when it drops, indicating a weak or painful gluteus medius.
Conditions That Can Cause a Positive Result
- Weakness of the gluteus medius
- Hip instability and subluxation
- Hip osteoarthritis
- The early period after total hip replacement
- Superior gluteal nerve palsy
- Lower back pain
- Legg-Calvé-Perthes disease
- Congenital hip dislocation
Pain can also produce a positive test, because it can limit how hard the abductors are able to work.
Trendelenburg Gait
Abductor insufficiency can also show up while walking, as a Trendelenburg gait. It is characterized by:
- Pelvic drop during the swing phase
- Trunk side flexion toward the stance limb
- Hip adduction during the stance phase
A true Trendelenburg gait shows the pelvic drop. In a compensated gait, the person shifts the trunk over the stance leg to reduce the load on the weak abductors.
Limitations to Keep in Mind
The Trendelenburg test is useful, but it is not perfect. Interpretation of the results remains controversial because there is no established standard for a positive test. In a quasi-experimental study in Clinical Journal of Sport Medicine, researchers used a nerve block to reduce hip abductor strength in healthy men. They concluded that the test should be reserved for populations with marked hip abductor weakness, rather than used to screen for milder strength deficits. A person can also compensate with a trunk lean and produce a “negative” test despite real weakness. For this reason, clinicians usually combine the test with manual muscle testing, gait analysis, and imaging when needed.
When to See a Healthcare Professional
Persistent hip or lateral thigh pain, a limp, or difficulty standing on one leg should be evaluated by a physician or physical therapist. Self-testing at home cannot replace a proper clinical assessment.
Frequently Asked Questions (FAQ)
What does the Trendelenburg test assess?
It assesses the strength and function of the hip abductors, mainly the gluteus medius and gluteus minimus, during single-leg stance.
How long should the patient stand on one leg?
About 30 seconds, while the examiner watches whether the pelvis stays level.
What does a positive Trendelenburg test mean?
The pelvis drops toward the unsupported side during single-leg stance. This suggests the abductors on the stance side are weak, painful, or not working effectively.
What conditions can cause a positive test?
Gluteus medius weakness, hip osteoarthritis, hip instability or subluxation, superior gluteal nerve palsy, Legg-Calvé-Perthes disease, congenital hip dislocation, lower back pain, and the early period after total hip replacement.
What is a Trendelenburg gait?
It is a walking pattern caused by abductor insufficiency, with pelvic drop in swing phase, trunk lean toward the stance leg, and hip adduction during stance.
Is the Trendelenburg test always accurate?
No. Results can be hard to interpret, and some people with weak abductors compensate and show a negative test. It is best used alongside other examination findings.
Can I do the Trendelenburg test on myself?
You can observe your own balance in front of a mirror, but a clinician should interpret the findings. Always have something nearby to hold if you feel unsteady.
References
- Orthofixar. Trendelenburg Test.
- Trendelenburg Sign. StatPearls, NCBI Bookshelf. NBK555987 (PubMed ID 32310447).
- Steps toward the validation of the Trendelenburg test: the effect of experimentally reduced hip abductor muscle function on frontal plane mechanics. Clin J Sport Med. 2013;23(1):45-51. PubMed 22797529.