SWD - Short Wave Diathermy.
IFT - Interferrential Therapy.

Both are very commen abbreviations and something that should have been taught in an undergraduate course. I tend to agree with the random use of abbreviations however these are really standard and I welcome their use in this forum.

As for there use in sciatica. Why indeed? I thought that SWD machines were the realm of the creatures in a Dr Who episode. Perhaps they have made another earthly invasion 8o