What a common teacher training does and does not cover
A reasonable introduction, not a clinical qualification.
The widely used training standard is a course of a couple of hundred hours, typically covering positions, sequencing, some anatomy, philosophy and teaching practice. As an introduction to teaching a general class to healthy adults it is a reasonable foundation.
It is not preparation for working with injuries, chronic conditions, pregnancy, older bodies with reduced bone density, or people recovering from surgery, all of whom appear in ordinary classes. The anatomy component in most trainings is measured in hours.
Many teachers recognise this and pursue further study, and the good ones refer people to appropriate professionals rather than attempting to treat them. Nothing structural requires that, and the market does not distinguish between teachers who have done it and those who have not.
For a student, the useful questions are what further training a teacher has done and whether they have experience with whatever your situation involves. Teachers who take this seriously answer readily, and the ones who claim to be able to help with anything have answered differently.
There is a further gap in most training worth knowing about, which is how to teach rather than how to practise. A person who can perform every position may have no idea how to explain one to somebody who cannot, and teaching is a separate skill that a practice-heavy training does not develop.