This website has a 22-page PDF brochure explaining concepts on fibromyalgia, including tender points illustrated on a black and white drawing. If you want in-depth info about fibromyalgia, take a look at this brochure.
''for a diagnosis of fibromyalgia patients have to feel pain in 11 of 18 trigger points when they are palpated with the amount of pressure sufficient to blanch a finger nail.'' This web site explains about trigger point and fibromyalgia.