Christina Pinchess, 31, and two former colleagues deny child cruelty offences at Bright Sparks nursery in Taibach, Port Talbot, before it closed.
A work placement student had told Swansea Crown Court she saw a child get "flung" by the wrist by a staff member.
Jurors heard Ms Pinchess told police it is "not in my nature" to hurt children.
In an interview read aloud to the court, she said: "If I had ever used excessive force with children I would not be here (in my job) today.
"Have I ever picked up a child by their wrists? No. It's not something I would have been able to do because of a physical injury to my shoulder."
The prosecution say young children were force-fed and restrained as well as picked up by their wrists before being dropped to the floor.
Ms Pinchess, of Port Talbot, also said in the interview the four students who told police about the alleged ill-treatment "could have misinterpreted" attempts to feed children who were refusing their food.
The jury was previously told the four students had no previous experience of childcare.
Some of the students also said to detectives daily diaries - which said when children had their nap times - were "falsified".
But Ms Pinchess, who is eight months pregnant, told police: "The students were never involved in sleep times. That was not information (the diaries) they would have been privy to."
Officers also asked deputy manager Ms Pinchess if she had seen any ill-treatment while working at Bright Sparks.
"Absolutely not," she replied. "If I had ever seen anyone do that then I would have been furiousâ€¦.If I had, I would have said something straight away."
Bright Sparks' former owner Katie Davies, 32, is also on trial as is 22-year-old staff member Shelbie Forgan, both of whom are from Port Talbot.
All three deny causing cruelty to a person under the age of 16.
The trial continues.
A nursery worker accused of cruelty told police she could not have "flung" children by their wrists because of a shoulder injury, a court has heard.