The phrase "trained assistants" is correct and usable in written English.
Example Sentence: Our team of trained assistants will be available to answer any questions you may have.
Medical scribes are trained assistants who perform multiple documentation tasks under physician supervision to assist physicians during their care of patients.
Also, seek assistance if you have special learning disabilities; there are excellent, trained assistants in many schools and universities on call to help out.
Mr. McCartney and Mr. Copeland have at times depended on classically trained assistants, similar to the way politicians rely on speechwriters to finesse their ideas into fluid prose.
Spurs had five fully medically trained assistants pitchside that day, and there was, as ever, aid from the St John Ambulance unit.
Through contracts Sol LeWitt authorized the creation of wall drawings under his name but executed, in his absence, by trained assistants.
Even then he was already employing assistants; in his later works he clearly could only complete large commissions in the comparatively short time allotted by the extensive use of highly trained assistants working simultaneously on different parts of the frescoes.
Age, education, wealth, religion and partner's education were independently associated with delivery assisted by a trained assistant.
Philip was already a trained assistant dog for his disabled owner and readily followed Topál's commands.
Single-physician PS is becoming the standard of care internationally (with the provision that an appropriately trained assistant is present at all times) [18].
The training sessions were held individually at school by a trained assistant.
A mid upper arm circumference was measured by a trained assistant.
