Perth doctor Christine Caffrey has told a court she was not using her mobile phone when she drove into a man delivering Coles groceries, causing severe injuries to his legs.

Caffrey, who is on trial charged with dangerous driving causing grievous bodily harm, said she did not see Matthew Chapman or his delivery truck until it was too late.

Mr Chapman had his left leg amputated after he was crushed against his truck in Nedlands on August 8 last year.

The prosecution has alleged that Caffrey was distracted by her mobile phone when she drove into him, a charge the GP denies.

Yesterday, Mr Chapman told the court he had heard nothing before he was hit, including no locking of the car's brakes.

Records extracted from Caffrey's mobile phone and presented to the court showed that her daughter's number was dialled at 7.15pm.

Caffrey's daughter called her at 7.16pm, the same time that a nearby resident called triple-0.

Caffrey told the court today that she had left her workplace, a Dalkeith clinic some time after 7pm after finishing paperwork.

She said she was in the car when she dialled her daughter's phone number but that she couldn't get through and set off.

Her intention was to go to Mount Claremont to pick up her daughter from her friend's home, she said.

GP 'looked straight ahead' while phone rang

She told the court she had put the mobile phone on the front passenger seat before driving.

The driver of a supermarket delivery truck had his leg amputated after a car ploughed into him. ( ABC News )

"It was very dark and there was no other traffic on the road," she said.

Her mobile phone rang while she was driving but she said she did "nothing" to the device.

She told the court she was "looking straight ahead" as she drove along Vincent Street and did not use the phone while the car was moving.

She then "became aware of an outline of a shape... it looked very very big", she said.

Caffrey said she had been going uphill and it was very dark when she put her foot on the brake.

"A man was standing in front of the truck," she said.

"As I got close to the truck, he was standing looking at me. I hit him with a thud. I got out immediately."

Caffrey said Mr Chapman was lying on the road and his left leg was at an awkward angle.

She became emotional as she described how he had a severe injury.

She said she was shocked because she believed that her car had nearly come to a stop.

Earlier, Sergeant David Magorian told the court it was reasonably dark at the scene, but that there would have been several sources of light when the accident occurred, including Caffrey's car headlights and an indicator flashing on Mr Chapman's delivery truck.

While there was no evidence of braking, such as skid marks on the road, that did not mean Caffrey had not braked, he said.

The trial continues.