There are schools of chiropractic that work only in the neck.
What they are implying is that any imbalance in the lower part of the body will manifest as imbalance up above. That far, they're absolutely right. So they say, let's get the imbalance out of the neck; that far, they're right, too. But they're not getting to the underpinning--for me, balance in the neck is inextricably tied up with balance in the whole body. To get balance in the neck, you must bring harmony to the rest of the body first.
"Ida Rolf Talks About Rolfing and Physical Reality" edited and with an introduction by Rosemary Feitis"