Therapeutic chairs with 4D technology deliver the same benefits as those with 3D technology, but 4D rollers take the massage experience a step further. Designed to mimic the time-tested techniques of Japanese massage therapists, the rollers speed up and slow down at various points to give attention to muscle areas that need it most. Users have control over the rhythm and depth of massage, and many people say that 4D chairs offer the most human-like touch.