a violin teacher might need to touch a pupil to get a particular position right. I pointed out that this would also often be the case of a singing teacher
I'm afraid this is now very much advised against. It is not necessary to touch any pupil to get them to change hand position, bow hold, become aware of their breathing, etc.. The ABRSM video on Safeguarding advises such and the ISM Safeguarding podcast also advises that this isn't necessary. Both of these are available for anyone to watch. Of course, they are in addition to school Safeguarding annual courses. Sometimes it is hard using words to describe hand positions etc but it is entirely possible - I have to do this for classical guitar. The vocal teacher I know does not use any touch either. Imagination is key!
Well after more than 50 years of teaching I can honestly say that it is certainly not always possible not to touch a child for either explantion or resrtaint. I also think ithat to give the impression that all and any touching is suspect is an inhuman and dangerous policy likely to cause a lot of children to become thoroughly neurotic.
If the touching is normal and natural and has nothing sinister about it then it is a positive factor. We were not meant to live in spendid isolation of one another. I accept that some people are not happy with being touched but most children I meet during a teaching week wil happily greet me with a kiss on both cheeks. In a primary school situation there are sometimes children who are touch starved because of inadequate parenting and are apt to throw their arms around a teacher.. I and my colleagues wouldn't dream of pushing them away.
On my last teaching practice many years ago in a difficult London primary school a little girl cried when my supervisor told the class I would be leaving. She was a poor little scrap and was still crying when it was time to take the children out to play. My (male) supervisor picked her up and carried her down the stairs and by the time we got to the playground she was smiling. He just reacted to her distress - but he wasn't a person full of anglo-saxon restraint. He happened to be Polish. I have long forgotten the child's name but I have never forgotten the incident.