PC Benjamin Monk, 43, discharged his Taser three times at the ex-Aston Villa striker and then kicked the 48-year-old twice in the head as he lay on the ground.
Mr Atkinson, who was in the midst of a psychotic episode at his childhood home, was kicked so hard by the West Mercia Police officer that he was left with a shoelace imprint on his head.
At trial, Monk was found not guilty of murder but guilty of manslaughter, and was on Tuesday jailed for eight years.
Judge Melbourne Inman QC, the Recorder of Birmingham, found Monk had acted “reasonably” when initially firing the Taser to try to control the volatile situation, but he had gone on to use “unlawful” force by kicking Mr Atkinson.
“It is clear from the evidence at the scene that you were trying to calm and control Mr Atkinson”, he said.
“I’m satisfied you didn’t suddenly change and decide to gratuitously intend to cause harm.
“Whether it was the result of adrenaline or another cause, you did use excessive force with two kicks to the head with moderate force, which caused Mr Atkinson to become unconscious or added to his unconsciousness.
“Everyone is now aware of the potential serious effects of any traumatic head injury. In this case, there were two kicks, and I’m sure the unlawful force you used carried a high risk of really serious injury or worse, or it ought to have been obvious to you.”
The judge added: “You have let yourself and the force down.”
At the start of the sentencing hearing on Monday, Mr Atkinson’s sister Otis told Birmingham crown court how her “kind and loving” younger brother was “young at heart” and delighted in teasing his family.
She said his death had been “devastatingly hard” for them to take, likening the news to “looking out of the window and seeing that a part of this planet has broken away and was drifting off”.
“I miss him, I miss talking with him and listening to his quirky observations”, she said. “When something remarkable happens, I want to tell him but he is not there anymore.”
She added that they are reminded daily of his death, calling it “too horrific to be real”.
Mr Atkinson’s partner, Karen Wright, said in her impact statement: “His death has left a huge void in my life that can never be filled.
“I miss Dalian every day, and have lost my friend as well as my partner.”
Mr Atkinson, a child of Windrush immigrants, played for Sheffield Wednesday, Ipswich Town, Manchester City and Villa during his footballing career, which also included stints in Turkey, South Korea, and Saudi Arabia.
The court heard he suffered from heart and kidney problems after retiring from football, and was receiving dialysis at the time of his death in August 2016.
His physical health difficulties are suspected of sparking a psychotic breakdown, when the ex-footballer claimed he was the Messiah and suggested he had killed members of his own family.
At trial PC Monk argued that he was “frightened” in a six-minute confrontation at the Atkinson family home in Telford, Shopshire, on August 15, 2016, when he tried to calm down Mr Atkinson and then discharged his Taser three times in a bid to subdue him.
The ex-footballer smashed a glass door with his fists and was heard making death threats, the court heard.
“The torrent of adrenaline flowing through Mr Monk’s body must have been difficult to overcome”, his barrister Patrick Gibbs QC told the court.
“Which of us would say in good conscience that we could be sure we would have kept out heads in that moment?
“If Mr Monk let himself down and misjudged the level of force required in the heat of the moment, the court can be sure it was totally out of character. That moment of heat evaporated almost as soon as it began.”
The court heard Monk has police cautions from the 1990s for theft while an employee at Woolworths and a drunken incident. He was disciplined with a final written warning in 2011 for failing to disclose his past when becoming an officer.
Mr Gibbs said Monk has not worked in active policing since the night of the death in 2016, and has spent time volunteering at a Covid-19 vaccination centre in the last year.
Monk has been held in custody since Monday while awaiting his sentence.