:Re.; Point 1. It is important to note that the Corporate Health Group (CHG) "did not systematically review the literature but rather summarized reviews and studies undertaken by other researchers. As a result, the Background Paper’s content represents a narrative summary of research pertaining to whiplash injuries and mechanical neck disorders in the acute/sub-acute phase."[page 6] That's why the first reference for the Corporate Health Group is cited as (per your point #1): 
 ::Kroeling, P., Gross, A.R. & Goldsmith, C.H. (2005). A Cochrane review of electrotherapy for mechanical neck disorders. Spine 30, E641-E648. Summary: Corporate Health Group Inc. "BACKGROUND PAPER FOR PREPARATION OF ONTARIO PAF GUIDELINE WHIPLASH ASSOCIATED DISORDERS I & II - I. Electrotherapies" October 2006. p.22-3. Republished online by Financial Services Commission of Ontario . Accessed 21-04-2009. 
 :This means we are in fact using this as a secondary source. I still believe, regarding CHG and point 1, that this review should be included and that it is a reliable secondary source. The point, I'm trying to make is not regarding TENS, its regarding electromagnetic therapy being considered electrotherapy. A list of examples, from a cochrane study, reviewed by CHG is the only source I currently have.