Booth, a university professor in Portland, Ore., found that her lactation consultant and several friends also endorsed chiropractic care for kids.

After one visit, she was a believer, too: As chiropractor Elise Hewitt worked on Mac, "he began to quiver and shake, and it kind of scared my husband and me," Booth says. "But she explained (she) was releasing energy that was stored up incorrectly in his body and particularly his spine. … And almost immediately, we saw a change in his ability to move his neck." The nursing and tummy time problems cleared up, too, Booth says, as Mac continued treatments over several months.

Stories such as Booth's help explain why nearly 3% of children in the USA were treated with chiropractic or osteopathic manipulation in 2007, making it the second-most common form of complementary or alternative medicine for children, a government report said recently. (Most common: natural products, such as fish oil and herbs.)

But stories are not studies. Even practitioners such as Hewitt, president of the American Chiropractic Association's council on pediatrics, concede their work is not backed by the kinds of studies that would be required if chiropractic care were a drug. As the government report noted, "there is insufficient proof that (alternative practices) are safe and effective." The National Center for Complementary and Alternative Medicine, which released the report, was created to fill the research gap.

Chiropractors say they welcome the scrutiny. Hewitt says: "I wish there were more high-level studies." But she also says she is comfortable treating kids based on preliminary research, 100 years of chiropractic history and her own experiences.

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