The friction of rotation is still considerable, however, and tends to wear, toughen, and polish the area of the foot being rotated upon. As a comparison, in breakdancing, those who perform headspins often go bald. The foot is more tailored to absorbing and benefitting from such rotations, although perhaps not so much on hard level surfaces, as our natural environment usually is uneven and has some give. This is why it is easier and safer to do by implementing one of two factors: