The maximum known extension of a human neck is 40 cm (15.75 in) and was created by the successive fitting of copper coils, as practiced by the women of the Padaung or Kareni tribe of Myanmar (Burma) as a sign of beauty. Their necks eventually become so long and weak that they cannot support their heads without the coils. In some tribes the coils are removed to punish women who have committed adultery.

Only initial discomfort is reported after the coils are set, yet the distance from earlobe to collarbone lengthens to more than double the average. Legend says that the rings protect women from the tiger that killed an ancient princess. Because the practice can be fatal if the coils are removed, it has been increasingly discouraged in modern times. However, tourist demand has recently revived this dangerous practice, with Paduang tribe girls being initiated as early as five years old.