mc,

I've had a quick look through Alter's 'Science of Flexibility', 3rd Ed, 2004, where he makes reference to 'irridation' within a discussion of PNF (p.165). However, I can't find reference to a 'law' within that particular text.

FYI, Alter cites

Alder, Beckers, and Buck, 'PNF in practice: An illustrated guide', 2nd Ed, 2000

Holt, 'Scientific stretching for sports (3-s)', n.d.

and Surburg, 'Neuromuscular facilitation techniques in sports medicine' in The Physician and Sportsmedicine, 18(1), 114-127, 1981

as his sources.

Mike.