Barit1,
Not sure of the design similarities with the MD-11 but here goes. The body gear on that aircraft type, better known as the "peg leg", needed to be free moving to allow it to walk, so to speak. This was needed during loading/off loading/fueling due to weight changes and shifts. Especially the freighters. I have been flying the 747-400 for many years since then but it does not do the same. However, I have never flown an AirBus and consequently cannot comment.