Paramedics immobilised the man and took him to Whanganui Hospital to be checked. The man was status 3 at the time.
The man complained of pelvic, upper leg, and lower back pain.
Mr Stretton could not say how big the trucks were, except that they were "the sort of trucks you wouldn't want to be crushed between".
"They were large, large trucks."
He thought the accident happened at a worksite, where the workers might have been replacing wires.
A Whanganui Hospital duty nurse manager said the man was no longer at the hospital, but had been transferred out. It is not know where he has been transferred or what his condition is.
A Worksafe New Zealand spokesperson said Worksafe has been notified and is making initial enquiries into the incident.