The other day I was asked to "evaluate" a DVD to determine, whether its translation and eventually publication in Japan is worthwhile.
While I was watching the DVD, featuring three professional therapists (all university graduates), I noted that ALL of them kept rings, watches etc. on their respective hands and at least two of the three had finger nails clearly extending beyond the finger cups.
Probably I am very old-fashioned, but I learned "in school" - this in itself does not mean anything - that professionals are not supposed (I think even prohibited by (Japanese) law) to have rings, watches ... anything metal ... on their hands during the treatment. Personally I am very much in favor of this idea and NEVER have anything metal or otherwise hard on/at my hands.
The other day I was looking from some stuff and found on Wikipedia a picture of an acupuncture practitioner (see link). This clearly shows very long fingernails and even mark on skin, where those finger nails have pressed into the flesh (of the patient/model).