here's some placement links -
http://site.lgmedsupply.com/Pdf/Elec...ementChart.pdf
http://www.vitalityweb.com/backstore/tensplacement.htm
http://www.eastcoastinternational.ie..._treatment.htm

and

[How Safe is Electrotherapy?

Contra-Indications - Circumstances in which you should NOT use T.E.N.S.
Remember that the current emitted from a T.E.N.S. unit travels through the skin between pairs of electrodes and only penetrates to a depth of 1-2 inches (to the level of the underlying nerve fibres). Such a small electrical current does not pose any danger. However, although electrotherapy is one of the safest treatments available, there are a few circumstances in which it should NOT be used:

DO NOT use T.E.N.S. in the following circumstances:

* If you are in your first trimester of pregnancy (it is okay to use during labor – please consult your doctor)
* If you have numbness or less feeling over a painful area
* If you have pre-existing lymphoedema. T.E.N.S. may affect lymphatic circulation, causing further fluid retention. Issues of skin integrity should also be considered]
more info-
http://www.queenwestphysio.ca/strate...rotherapy.html