Gluteus Medius Strength Test (Trendelenburg): Protocol and What It Means

The Trendelenburg test is one of the classic physical therapy and return-to-sport assessments for evaluating gluteus medius strength and control — a key muscle for pelvic stability during single-leg stance (walking, running, climbing stairs). An abnormal result on this test is one of the most common findings in people with knee, hip, or low back pain.

What does this test measure?

It measures how well the gluteus medius on one side can stabilize the pelvis during single-leg stance on that same side. If the gluteus medius is weak, the pelvis on the opposite side (the side with the lifted leg) drops (a positive Trendelenburg sign), instead of staying level or rising slightly.

Equipment needed

• Nothing essential
• Optional: a wall for light support, a tape measure or level to quantify the pelvic drop, a smartphone to record and analyze in slow motion

Test protocol

1. The person stands facing you or with their back to you, arms relaxed or crossed over the chest
2. Ask them to lift one leg by flexing the hip and knee to about 90°, putting all their weight on the standing leg (single-leg stance)
3. Hold the position for 5-10 seconds
4. Watch the position of the iliac crests: under normal conditions, the pelvis stays level or the hip on the lifted-leg side rises slightly
5. Repeat with the other leg and compare both sides

Common mistakes

• Not observing from an angle that lets you clearly see both iliac crests
• Letting the person lean on a wall or object, which masks the real result
• Confusing a trunk compensation (lateral lean, "compensated Trendelenburg") with a negative result, when it actually indicates a compensatory strategy

How to interpret the results

Result	Interpretation
Pelvis stays level or rises slightly on the free-leg side	Negative — good gluteus medius control
The pelvis on the free-leg side drops	Positive (true Trendelenburg) — weakness or inhibition of the gluteus medius on the stance side
The trunk leans toward the stance side to compensate	Compensated Trendelenburg — also indicates gluteus medius weakness, masked by a compensatory strategy

A positive result doesn't necessarily mean there's an injury, but it does point to relative weakness of the gluteus medius that's worth addressing with targeted work, especially in people with knee pain (dynamic valgus), hip pain, or low back pain.

Related tests

The Trendelenburg test pairs well with:

• Single leg glute bridge test — adds a more dynamic, measurable assessment of glute strength
• Side plank lumbopelvic control test — assesses lateral core stability, related to gluteus medius function

Track and monitor progress

Spotting a positive Trendelenburg is just the first step — what matters is checking whether it improves with targeted gluteus medius work. With Movalytics you can log the result for each side (negative, positive, or compensated) at every assessment, and track whether the pattern improves as the athlete progresses through their hip strength program.

Frequently asked questions

Does a positive Trendelenburg mean there's an injury? Not necessarily. It indicates weakness or inhibition of the gluteus medius that can be addressed with targeted training, though if pain is present it's worth having a physical therapist evaluate it. What exercises help correct it? Targeted gluteus medius work: bridges with leg raises, lateral band walks, single-leg squats with pelvic control, among others. Can this pattern show up while running or walking? Yes — in fact, it's often spotted first during walking or running (the contralateral hip drop) and then confirmed with the static Trendelenburg test.