From a PT's perspective it follows the 'unloading principle' by providing some traction to the spine. Skiing would be the opposite. It is a load under compression and often flexion or forward bending. Downside is it is short term relief because as soon as you come off it your loading the spine again.
There is more to the back management approach which would include hip flexor, piriformis stretching and foam roll techniques. Additionally, myo fascial release would be included.
Hope that helps!