The anchoring strengths of various chest hair root types.

The force required to epilate single chest hairs was measured electronically during a slow (0.09 m/s) machine-driven extraction. Telogen hairs showed a mean anchoring strength of 70 g (s.d. = 16). Anagen hairs, with variable amounts of surrounding root sheaths, had a mean of 71 g (s.d. = 10) whereas bare anagen hairs had a mean of 66 g (s.d. = 13). The catagen phase had a mean of 62 g (s.d. = 8). It is highly likely that the anchoring mechanisms of anagen and telogen roots are as different physiologically as these roots are different anatomically yet both are sufficiently strong to resist the ordinary tractions and pullings to which hair is subject.