Magnetic hobble-field

A magnetic hobble-field was the radiation generated by a magno-grab. Such a field once ensnared the Doctor's TARDIS and nearly caused the ship's destruction. It was activated, and later de-activated, through the use of a magno-grab remote. According to the Eleventh Doctor, such radiation could normally be countered by shield oscillators, but his were disengaged at the time the field was generated. (TV: Journey to the Centre of the TARDIS)