An Edmonton police officer is denying he kicked a teen in the head following a car chase more than four years ago.

Const. Glenn Thursby was helping RCMP officers who had stopped a stolen vehicle on the median on the Yellowhead Trail in Strathcona County in 2009.

Thursby is facing one count of unlawful or unnecessary exercise of authority.

The chase started when a vehicle had rolled through a stop sign in Vegreville. The driver of the vehicle didn’t stop for RCMP, continuing along Highway 16.

Thursby testified Wednesday at his disciplinary hearing that while the teen was handcuffed on the ground another officer was tripping on him.

Thursby said he took the teenager to the top of the steep median for his own safety.

However the teen tried to get up so Thursby put his foot on the boy's back, he said. 

When the teen tried to get up again, Thursby put his foot on the side of the teenager's head twice to keep him down, but he never kicked him, he testified.

He told the hearing he would have used his knee, but the slope of the median was such that he might have lost his balance.

However it was pointed out that the explanation differed from what he said in a statement four years ago.

Thursby explained that after that statement, he had returned to the scene and his memory was refreshed.

Defence lawyer Mike Danyiuk pointed to discrepancies in evidence provided by two RCMP officers. 

While they both said they saw Thursby stomp on the boy's head, one said that happened in the ditch near the stolen vehicle, while the other said it occurred at the top of the median.

The presiding officer of the disciplinary hearing will announce his decision on Feb. 4.

With files from the CBC's James Hees