It is so bizarre to me. The protocol for "delivering" a breech in North America (and many other places evidently) is mama in lithotomy, usually with a great big episiotomy. In Canada, the "hands off the breech" rule applies from the birth of the navel until they see the nape of the neck. They usually help the legs and arms come through, but then it is believed that teh baby should be allowed to "hang" because it ensures the tucked chin that brings the head out safely. Once they see the nape of the neck, they're supposed to take hold of the chin to ensure it stays tucked.
Truth be told, when you do international research, this is pretty much all as unnecessary as any other "routine" birth intervention. Michel Odent says the only thing he insists upon for breech delivery is that the mama be in an assisted squat to open the pelvis. Mary Cronk (and from her lead, many or most other MWs in teh UK) catches breeches in whatever position the mama chooses, and if the mama isn't sure, hands & knees tends to be the recommended position. the shape of the uterus keeps the chin tucked, as long as it was tucked in the first place... breech stargazers tend to be more trouble in delivery and IMO would be a reasonable medical indication for the mama to choose c/s instead of delivering vaginally. The "hanging" thing, again, not so important since if the head is tucked already, it'll stay tucked by virtue of the shape of the uterus, and so long as nobody pulls on the baby there's no particular threat to the spinal cord. My favorite Mary Cronk quote is "the best thing a doctor can do when delivering a breech is to get a very tall beer, or a very hot cup of tea, sit on a stool facing the corner, and drink it very slowly." Her belief, and I am convinced she's right, is that most problems with breech delivery are CAUSED by breech "management" and if you leave the birth completely alone, it'll be just fine.