I think measuring is the most important bit for stooping and making a bad back worse. But power feeds certainly help, especially if there is a trip-out system that works.
Mike’s ideas of raising either the lathe stand or the operator are good. Shortening legs is more difficult unless they are easily adjusted/levelled. Leaning against a stool is more apprpriate than actually sitting – one cannot move as quickly from a sitting position if something goes awry.
One should never allow students to sit in front of chemistry experiments, for instance – well, I never did, for one. Clear access – or escape – required at all times, and no trip hazards!