How we Score and Test Mattress Motion Isolation

What motion isolation tells you

Motion isolation measures how much movement reaches the other side of a mattress. Strong isolation helps reduce disturbances when a partner changes position, gets into bed, or leaves during the night.

How we test motion transfer

We place a calibrated accelerometer on one side of the mattress and drop a 12-pound medicine ball on the other side. The ball, sensor, and drop locations remain fixed so reinforced perimeter materials do not distort one mattress's result relative to another.

The sensor records acceleration in meters per second squared (m/s²). We calculate the range between the minimum and maximum acceleration created by the initial impact and rebound. A smaller range means less movement reached the sensor. We also record how long it takes the signal to return to near zero, although motion duration is reported as context rather than used to replace the measured acceleration result.

We repeat the controlled drop to check for an outlier, then perform practical movement checks with a tester changing positions and entering or leaving the bed. The instrument result establishes the baseline; the body test helps explain what the recorded movement feels like.

How the score is assigned

Motion isolation is scored from 0 to 10 and contributes 12% of the overall mattress score. Lower measured acceleration transfer produces a higher score. Motion duration and construction explain how the recorded movement is likely to feel without replacing the standardized acceleration result.

The review publishes the score beside a plain-language explanation so couples can decide whether a small amount of bounce is acceptable for their sleep sensitivity.

Motion-transfer score table

The peak-to-peak acceleration range is the scoring input. Lower transfer receives the stronger score. Results between two anchors are linearly interpolated and rounded to one decimal place.

Individual reviews show a measurement interval spanning 2% below to 2% above the recorded reading, without publishing the midpoint. We use that midpoint for the score and check both endpoints to identify any one-decimal score or performance-band sensitivity.

The widening intervals reflect the practical difference between a nearly still surface, noticeable partner movement, and increasingly disruptive transfer without pretending that every additional unit has the same effect. Motion duration remains visible because a brief spike and prolonged movement can feel different, but it does not replace the standardized acceleration result.