Students grabbed, wrestled to the floor and strapped to chairs three or more times a day

The 15-year-old is confined to his own portable classroom, which opens onto a fenced-off playground.

The fence has been covered in sheets of plastic, which means Jack – who is autistic, non-verbal and has an intellectual disability – can't see out. It also means no one can look in.

His mother Sandra was told that the plastic sheets were needed because her son took his clothes off.

She has seen staff lock Jack in the classroom, and says he is unable to leave the playground.

"It's like walking into a dungeon everyday, he is all on his own," his mother Sandra* says. "He needs to be humanised, not treated like an animal."

Students are secluded like this or grabbed, wrestled to the floor and strapped to chairs three or more times every day in Victorian schools. Most of these students have disabilities and behavioural issues.

They are also being held flat on the ground in the prone position – a controversial manoeuvre, that can restrict breathing and has led to a string of child deaths overseas.

Closer to home, a Canberra school came under fire in 2015 for locking an autistic student in a cage, while in Victoria, Bendigo Special Developmental School placed a child who suffered seizures in a pen.

For the first time, new data provided to Fairfax Media reveals the extent to which restraint and seclusion is used in Victorian schools.

Between October 2015 and the end of March this year, the controversial practices were used on students 984 times during the school year.

And according to the latest annual survey by Children and Young People with Disability Australia, 38 per cent of families said their disabled children had been restrained or secluded at school.

It's a fraught and complicated issue, according to Jack's principal.

He says Jack has broken two teachers' noses and bitten, bruised and hit other staff. He is worried that if Jack interacts with other students at school, they will also be hurt.

"It's a balancing act between having a student in a class where he hurts people, and putting him in his own classroom," he says. "He's a boy who needs his own space. Whose child do I sit him next to?"

Restraint and seclusion is meant to be used as a last resort in Victorian schools. Under Education Department rules, it can only be used when a student is at risk of hurting themselves or others. Schools must also inform parents when the controversial techniques are used.

But parents like Melissa* say they have been kept in the dark.

Melissa only found out that teachers were grabbing her daughter's wrists and holding them behind her back after requesting the details through Freedom of Information.

According to a staff email, Melissa's daughter, Nicki*, was removed from class for up to 90 minutes every morning, and restrained. She was just seven-years-old.

In a 2013 guide for teachers dealing with Nicki, restraint was named as a recommended method to manage the young girl. In 2014, the restraints allegedly injured her arm.

"You expect a school knows what they're doing with your child," says Melissa, who is suing the Victorian Education Department for discrimination.

"You expect your child will be safe when they go to school."

In a statement of defence, the department denied that Nicki was secluded and restrained up to 90 minutes a day, but admitted that in 2013, at least one teacher held her by the wrists to stop her from kicking and punching staff.

Melbourne University Professor Keith McVill, who has advised the department on its restraint policies, says students have broken bones after being restrained, or thrown to the ground using the "takedown technique". This involves forcibly pushing a child to the ground and holding them down.

McVill, who is a clinical psychologist, says students are still being put into the prone position, which has been banned in Victorian schools.

"There have been some programs brought into schools where teachers have been taught the basics of what can only be described as martial arts techniques.

"In one instance, the teacher is expecting the child to engage in an educational relationship and in the next instance, the teacher is becoming very violent ... there is an incongruence there," he said.

Joseph Ridley, the Arnold Thomas & Becker lawyer representing Nicki in court, said he has seen a "substantial increase" in disability discrimination cases brought against the Victorian government.

In a bid to clean up the practice, in 2015 the Victorian government asked all schools to report restraint and seclusion, and employed a principal practice leader to oversee its use and recommend reforms.

It has also banned restraints involving straps or harnesses, holds that restrict breathing and rooms or areas that are solely used for seclusion.

But Natalie Wade, from Australian Lawyers for Human Rights, says she still receives reports about students who are pinned to the ground or locked in small, dark. "It's almost like a prison cell," she says.

While grabbing a child's arm to stop them from running on the road is clearly necessary, Wade says schools have a responsibility to prevent children's behaviour from spiralling out of control.

"Restrictive practices are often dressed up as behavioural management techniques, so staff will say the child is too violent, or this child presents a safety risk to other children or staff, so we have taken these restrictive measures," she says.

"It is our view that the situation should be managed so as to ensure restrictive practices are not resorted to."

It's a view that's shared by Jack's mother, Sandra.

She says her son's violent behaviour is exacerbated by his isolation. "He is not like this at home. He is too closed up at school, they are not teaching him what he needs to learn," she says.

"I understand that they are trying to do their best but he shouldn't be removed from other students."

She points out that he has never hurt a classmate. But it's not a risk that his principal is prepared to take. "The best predictor of future behaviour is past behaviour," he says.

Disability advocates including Julie Phillips want restrain and seclusion to be banned in schools.

Schools continue to include restraint in children's behaviour management plan, which is a breach of department rules, she says.

Children and Young People with Disability Australia's executive officer Stephanie Gotlib says there's not enough accountability over when force was used, how, and whether positive alternatives could have been adopted.

"In most cases, this would be seen as abuse, but here it's being classed as acceptable practice and there is little accountability for it."

Victoria's Public Advocate Colleen Pearce wants seclusion to be banned in schools. And she says physical restraint should only be used as a last resort, "where the child's behaviour poses an imminent danger".

She says strict guidelines, that were enshrined in laws, were needed to protect students.

"School students with disability are one of the last remaining groups in society who can have their liberty and freedom restrained without proper guidelines," she says.

Sandra says it broke her heart to watch paramedics inject sedatives into her son's arm, after a violent outburst at school.

Police were called to the school after Jack smashed a window. Three teachers barricaded the classroom door as Jack grew increasingly agitated inside, with tears streaming down his face.

Sandra was called to the school and says she saw her son being thrown to the ground and handcuffed by police. From behind the locked door, Jack shouted out the one word he knows. "Home, home, home."

He was taken to hospital where he was diagnosed with an ear infection.

"It broke my heart," she says.

Psychologist Karen McKinnon, who trains staff at 60 Victorian schools to work with autistic students with complex behaviour through an organisation called Autism Partnership, says teachers could use non-violent methods to calm a child, even when they pose an immediate risk to themselves or others.

McKinnon says if the child is spinning out of control and becoming violent, the classroom must be evacuated. A staff member must use a calm voice to help soothe the student, and avoid physical contact.

These are high-risk situations which require teacher training, according to the Australian Education Union.

Justin Mullaly, the union's deputy president, said the union has supported several teachers in compensation cases against the Education Department after they injured themselves while trying to restrain a child, or diffuse a violent situation.

Last year, a teacher won such a case in the County Court, after injuring her back when she was "forced to wrestle with [a] child on the floor". The child was autistic.

In an attempt to provide teachers training, Victorian schools have controversially hired Jiu-Jitsu trainers and martial arts experts to manage student behaviour.

Crisis Prevention Institute, a company which trains staff in prisons, mental health facilities and nursing homes to deal with violent people, is being called upon to teach non-violent interventions in schools across the country.

But McVill says managing complex behaviours requires teams of qualified psychologists, speech therapists, occupational therapists and teachers.

He warns against using "simplistic workshops" to manage students with special needs.

McVill is concerned about schools' focus on teaching staff how to restrain students. "If they are only taught physical restraint, then that's what they will rely on," he says.

As part of a pilot program with Victorian schools, he is teaching schools a research-backed methodology called Positive Behaviour Support, which encourages teachers to identify the cause of a students' behaviour, adapt the students' environment to make them comfortable, and help them them develop skills to communicate their needs.

Research shows that toothaches, stomach problems and other physical pain or psychological trauma often caused people with disabilities to lash out, and if the underlying needs were addressed, the behaviours would occur less frequently, if at all.

"These people have complex and sometimes very painful conditions, time and time again we see that these behaviours are a result of poor pain management," says McVill.

Principals Association of Specialist Schools president Helen Hatherly says introducing Positive Behaviour Support in schools would improve student outcomes.

"It's not an easy quick response, it takes a long time of sustained change, but if the school environment is a positive one, and is based on praise for students when they do well, it does work."

A department spokesman says: "The department takes very seriously any allegation of mistreatment of students, and where necessary, will take all appropriate steps to ensure a full investigation is undertaken, including appointment of independent investigators".

Jack's principal says police treated the young man with kindness after he smashed the classroom window. "It was extremely stressful," he says. He says police placed Jack on the ground after he hit them. Jack was bleeding profusely from the smashed glass.

"I need to balance protecting staff and students against Jack's right to be in school," he says. "It would be nice to have him in the classroom with the other kids. It's a bit more nuanced and complicated."

Definitions:

Restraint: The use of physical force or a hold that prevents restricts or subdues movement of a student's body, head, arms or legs.

Mechanical restraint: The use of materials such as straps, belts or harnesses to prevent a student's movement.

Seclusion: The forceful confinement of a student alone in a room or area from which the student is physically prevented from leaving. This includes situations where a door is locked, as well as where the door is blocked by other objects, or held closed by staff. This is different from time out, when a student is separated from others to calm down.

*Names have been changed