Nicole Short claimed she was told for the first time that Sheku Bayoh had stamped on her head in the canteen following the incident which took place in Kirkcaldy on May 3 2015.
The former officer told the inquiry Mr Bayoh had been in a "press-up" position and had managed to lift three officers off of the ground.
She said: "I can't say for certain who was where, but I just remember Mr Bayoh, I'm positive he was in a kind of press-up position and he was trying to get up off the ground.
"I just remember thinking, 'those are three of the biggest guys on shift and he's managing to lift them up'. It was like nothing I had ever seen before in my life."
Angela Grahame QC, senior counsel to the inquiry, asked Ms Short if she could recall where her colleagues were standing.
Ms Short replied that she could "not say with certainty" but recalled the three officers "struggling" with Mr Bayoh whom she described as "just about overcoming them".
She added: "He was just about overcoming them if you know what I mean, and I just remember being horrified.
"I had a genuine belief he was going to get up and finish me off."
Ms Short described how Mr Bayoh had been surrounded by officers with one officer at each of his arms.
In her first witness statement relating to the incident, Ms Short said Sheku Bayoh was "derranged with superhuman strength".
She was asked by Ms Grahame what was meant by this, to which Ms Short replied: "I would say initially the super human strength element came with the Pava (pelargonic acid vanillylamide spray) and the CS spray having absolutely no effect on him.
"The next one was the strength that he showed by lifting those three male officers off the ground.
She believed the level of restraint was "completely in line" with the violence and resistance shown by Mr Bayoh.
The former officer was taken to hospital for treatment after the incident.
She told the inquiry how she felt after the events that lead to Sheku Bayoh's death. Ms Short said: "Physically I felt sore. Sore head, knees hands, side.
"Emotionally, I just felt absolutely broken, to be honest.
"I burst out crying in the van I compare it to when a child really, really cries. I was shaking with fear, adrenaline, I couldn't catch my breath."
Ms Short said it "didn't go through her head" at the time that the officers had been taller than Mr Bayoh whom she later learned was 5ft 10in.
Ms Graeme asked what it was about Mr Bayoh's demeanour that made her feel he was the most "frightening, crazy man" she had ever seen in her life.
Ms Short replied: "Walking on a mission, not listening to a word they were saying. There was nothing there. His pupils were big and black. Nothing we were saying was registering, he was kind of just doing what he wanted.
"The most frightening thing for me was seeing the spray not working on him.
"It was so out of control."
Ms Short was asked if they would have employed the same tactics had Mr Bayoh been white. She replied: "The actions would be the same. The colour of his skin had no bearing on how we reacted to that call whatsoever."
On Tuesday morning, the inquiry heard how Ms Short had ran from Mr Bayoh after being "overwhelmed by terror" before falling to the ground after receiving a blow to the head.
Nicole Short said she felt "fearful" and "scared" when she arrived at the scene.
The inquiry has been told Ms Short has been rendered "permanently disabled" from injuries she sustained on the day of Mr Bayoh's death.
An inquiry into the circumstances of Mr Bayoh's death, and whether race was a factor, is taking place at Capital House, Edinburgh.
Ms Short, who the inquiry heard is 5ft 1in tall, was one of the officers responding to 999 calls that Mr Bayoh, 31, carrying a knife in the town's Hayfield Road just after 7am.
Describing how she arrived at the scene on Hayfield Road, she said: "I was fearful, I was scared, I felt like my priority was to deal with what was in front of me."
Last week, Pc Craig Walker said he saw Mr Bayoh "stamp" on Pc Short.
On Tuesday morning, supporters of Sheku Bayoh's family took the knee outside the inquiry.
Mr Bayoh's mother, Aminata Bayoh, and his sister, Kadi Johnson, arrived to chants of "Black Lives Matter" and "No justice, no peace, no racist police" from about 50 protesters.
Present with the family was their lawyer, Aamer Anwar.
Speaking about Mr Bayoh's family, Mr Anwar said: "They have been fighting for justice for some seven years now and this struggle is not over."
Mrs Bayoh thanked the protesters for coming to show solidarity with the family ahead of the evidence being heard.
Roddy Dunlop QC, who is representing Ms Short and another officer, said: "It would be naive to think that the events of that day have not had material impact on the lives of the families of the officers who attended the scene that day."
Mr Dunlop said there have been accusations of racism directed against those officers and "such vilification has a lasting impact".
The inquiry, which is examining the immediate circumstances leading to the death of Mr Bayoh, how the police dealt with the aftermath, the following investigation, and whether race was a factor, continues.