Romberg Test on Unstable Surface (Foam): Protocol and Differences from the Classic Romberg

The Romberg test on an unstable surface, also known as the foam Romberg or Foam Romberg Test, is a progression of the classic Romberg test that drastically reduces proprioceptive information from the ground, forcing the vestibular system and motor control to work much harder.

If the classic Romberg seems "too easy" for an athlete or someone with good control, this version will give you much more information.

What does this test measure?

Just like the classic Romberg, it assesses static balance and reliance on visual information, but by placing the subject on a foam surface (unstable and deformable), the information arriving from the proprioceptors in the sole of the foot and ankle is greatly reduced.

This makes the test much more sensitive for detecting subtle proprioceptive deficits that would go unnoticed on a firm surface, especially useful after ankle injuries (recurrent sprains, chronic instability).

Equipment needed

• A medium-density foam surface (foam discs or pads like Airex are most commonly used), at least 5-10 cm thick
• Stopwatch
• A safe space, with a wall or person nearby to prevent falls

Execution protocol

1. The subject stands on the foam surface with feet together, arms crossed over the chest or at their sides
2. Allow a few seconds for them to adjust to the initial instability of the foam
3. Ask them to hold the position with eyes open for 30 seconds, observing the amount of sway
4. Then ask them to close their eyes and hold the same position for another 30 seconds
5. Observe and compare the sway between both conditions, and relative to what would be expected on a firm surface
6. Stay close to the subject at all times, ready to intervene

Common mistakes

• Using foam surfaces of very different densities between assessments (this significantly changes the difficulty and makes results non-comparable)
• Not allowing initial adaptation time to the foam before starting the timer
• Doing this directly without first performing the Romberg test on a firm surface, losing the point of comparison

How to interpret the result

Result	Interpretation
Stable with eyes open and closed on foam	Good proprioceptive and vestibular control, even with reduced input
Stable with eyes open, markedly unstable with eyes closed on foam	High visual dependence and/or proprioceptive deficit — common after ankle injuries
Unstable even with eyes open on foam	Significant proprioceptive deficit in the lower limb

The main value of this test lies in the comparison with the Romberg on a firm surface: if the subject passes the standard Romberg without issue but becomes notably unstable on foam, that points to a specific proprioceptive deficit that the firm ground was "masking."

Relationship to other tests

• Romberg test — the baseline version on a firm surface, a mandatory prior step before progressing to foam
• Knee proprioception test — assesses proprioception in a more localized (joint-specific) way, complementing the more global view of this test

Track proprioceptive training progress with data

This test is ideal for showing progress in ankle sprain prevention programs or proprioceptive retraining after injury. With Movalytics you can record the time held under each condition (eyes open/closed, firm/foam surface) and see how your athlete's tolerance evolves as they progress through their balance program.

Frequently asked questions

What type of foam is recommended? Medium-density discs or pads (such as Airex or similar), soft enough to reduce proprioceptive input but not so soft that they become impossible to use. Is it safe to do this test with eyes closed on foam? Generally yes, but extra caution is needed with older adults or people with a history of falls: start with eyes open and only progress to eyes closed if the result on a firm surface was already good. How does it differ from a test on a BOSU? Foam is more stable than a BOSU (which has a hemispherical surface and is much more unstable), so the foam Romberg is usually used as an intermediate step before progressing to BOSU-type surfaces.