Motion transfer can occur in any bed regardless of firmness level, but customers of size tend to experience more motion transfer—and more sleep disturbances because of that transfer—than other sleepers. If your mattress is made of flexible springs or continuous coils, you will feel the disturbance more prominently. Individually encased coils, particularly those of industrial strength, or higher density foams (like memory foam) will reduce motion transfer best, allowing for a deeper, uninterrupted sleep.