I got this reply from Nigel Schofield, when I asked if they were callouses. He says: It's much more specific than that. Segs is a Northern dialect word (Barnsley to Halifax then west into Lancashire on the Leeds University dialect map) It means "broad cuts" - i.e. ones that have a shape rather than just straight lines (as in "cutts and segs" (sic)). It's related to the French "segue" which is used in music (and inaccurately in the radio industry) to describe the seamless joining of two pieces. It is still used in Yorkshire, to describe the piece of leather/rubber etc inserted after cutting of a hole in a worn or damaged shoe soles. The cobblers I pass each day on the way to work has a display card marked "seggs" (sic) in his window showing different sizes, colours and shapes of standard insertions. Two or three years ago, they became fashionable among students who went clubbing. An interesting coincidence as Spanish has a similar word for the metal inserts in flamenco shoes and of course Bojangles referred to the "sigs in my tap shoes". Hope that's of use