Residents of villages in the Falkirk area were left without power after a car left the road and hit an electricity pole.
The incident happened shortly after 07:00 on the A905 at Airth.
The Scottish Ambulance Service said a 29-year-old male casualty was taken to the Forth Valley Royal Hospital. His condition was described as "stable".
The road is closed between Bowtrees and the approach to Airth, with local diversions busier than usual.
It is understood that the road is likely to remain shut for most of the day.
Police Scotland said the closure was to enable repairs to be carried out to the pole.
"Inquiries are continuing in to the cause of the crash," added a spokeswoman.
The Scottish Ambulance Service said it had sent an ambulance, its special operations team, and an air ambulance to the scene.
"We transported one male patient to Forth Valley Royal Hospital by road," it said.
Local councillor Laura Murtagh said it was a "very sad incident" and her prayers were with anyone who may have been injured.
She said the power had been cut to a number of local villages as a result of the crash but most had now been restored.
The councillor advised HGV drivers "not to attempt" the A905 due to other local diversions.