Mrs Sunderland, an advanced-skills teacher from Bradford, was charged with common assault after holding the arms of a 13-year-old boy who was abusing and kicking out at her.
She was suspended in May 2004, following several months of sick leave. But charges were dropped in June this year, when the prosecution admitted there was no evidence.
"There is an idea that teachers aren't allowed to touch children," Mrs Sunderland said. "They use 'you can't touch me' as a taunt. Students will claim assault if you bump into them. The threats come because legislation is vague. It leaves teachers open to false accusations."
In many cases, she says, restraint is required to prevent children from injuring themselves, other pupils, or members of staff, where verbal warnings have not worked. At other times, physical restraint is the only means of stopping a child from damaging school property.
"Teachers need to be able to make a professional judgement, taking into account the circumstances they find themselves in," the 56-year-old said.
"But physical contact is an area that is becoming fraught for teachers. You have to think twice before you put a hand on a student's shoulder, or pat them on the back to say well done. Teachers are scared of what will happen."
So she welcomes any government efforts to clarify teachers' rights to use reasonable force to restrain pupils. "It's eminently sensible. Once an allegation has been made to the police, there has to be an internal inquiry. It's very, very stressful.
"The public needs to know that teachers can do this, and it doesn't mean that children are being attacked wholesale."