Jeffrey Crowley of Blackhall Parade, Dublin 7 pleaded guilty at Dublin Circuit Criminal Court to attempted robbery at St James's Hospital Luas stop on April 7, 2014.
Ciara Dunne's arm was fractured when the Luas door closed on it. She had been standing near the door when it stopped at St James's Hospital. As the doors closed, Crowley, who was standing on the platform, grabbed her umbrella and tried to pull it away from her.
Garda Barry Hayes identified Crowley from CCTV footage of the incident. He was arrested and admitted his involvement. He said he was on drugs at the time.
Imposing a two and a half year sentence with the final 12 months suspended, Judge Terence O'Sullivan said the attack was a frightening experience for the victim.
In a victim impact statement Ms Dunne said she still suffers pain in her arm, is now much more wary on public transport and feels vulnerable to attack.
Crowley has 37 previous convictions including theft, robbery and criminal damage.
Pieter Le Vert BL, defending, said Crowley had a difficult upbringing and will soon become a father himself.
He is determined that what was visited upon him not be visited upon his own child, said Mr Le Vert, and he is now completing his Leaving Certificate and undergoing treatment for drug addictions to improve his future prospects.
Judge O'Sullivan said he took Crowley's youth, guilty plea and expression of remorse into account, but that it was not a trivial crime. He ordered that Crowley abstain from narcotics on his release