Jonathon Stephen Lowe (34) was sentenced in the Perth District Court on Tuesday to three years jail with a non-parole period of 18 months.

Lowe had pleaded guilty to the grievous bodily harm of his three-month-old son.

The assaults left the child with 38 broken bones.

The court was told Lowe admitted to injuring the boy during at least two serious assaults between March and April last year.

Judge Michael Bowden sentenced Lowe for the assaults that led to the child receiving 33 fractured rib bones, but did not take into account five fractures to his legs.

He said the injuries, which did not constitute a threat to life, had resulted from the man’s “deliberate, non-accidental” mishandling of the child.

A doctor’s evidence indicated the boy had been heavily squeezed on at least two occasions and had been in danger of having his lungs perforated as a result of the multiple rib fractures.

During sentencing submissions, the court heard Lowe was suffering medical problems through a rare genetic disorder known as Usher’s syndrome, which could lead to him losing his eyesight and hearing.

Lowe had also been using alcohol, marijuana and amphetamines at the time of the assault.

Judge Bowden said it appeared Lowe was in a stable relationship with his partner of three years and wanted to get treatment for his anger management problems, which could have triggered the assaults on his son.

Lowe’s lawyer Mara Marone said the child was now in foster care, had no permanent injury or discomfort from his injuries and had not been the subject of a prolonged and brutal attack.

She said psychiatric reports had indicated there was also a good chance of Lowe’s rehabilitation.

“The injuries are serious and clearly amount to grievous bodily harm and the maximum penalty for this crime could be 14 years,” Judge Bowden said.

“At the end of the day, notwithstanding your personal circumstances, notwithstanding your plea of guilty I do accept that you’re making genuine efforts as far as your rehabilitation is concerned, and I do accept that you’re remorseful.”

“I do accept that you have served 197 days in custody, and I do therefore order that the period of imprisonment commences from 30 March 2009,” he said.

Judge Bowden also placed Lowe on a permanent violence restraining order preventing access to his son.