MADISON, Wis. -- A new study by the Emergency Nurses Association finds workplace violence is all too common in the nursing profession, but it's patients and their families -- not co-workers -- that the violence typically stems from.

According to the survey of more than 3,000 nurses, more than half said that they have experienced physically violence on the job. Even more alarming, one in four of those nurses said they have been physically assaulted more than 20 times in the last three years.

In Madison at St. Mary's Hospital, nurse Nicole Pullin said that she isn't terribly surprised by the study's findings.

"They'll spit, they'll pinch, they'll grab, they'll kick at you," she said. :The ones that just aren't getting what they want out of their visit, they get very verbally abusive and in your face."

The story is similar for University of Wisconsin Health ER charge nurse Dianna Bower.

"I've been spit on, I've been kicked, I've been called every name you can think of," Bower said. "We know we're giving great care and we just have to ignore some of it because these people are in pain and they're grieving and they're upset."

In addition to the obvious medical training, both women have had something less obvious: Schooling in non-violent crisis intervention and self-defense. Tactics include how to break free of a patient who might be trying to grab hold of hair or an arm, without causing injury to the patient.

"When a patient acts out they not only put our staff in danger, but they can put other people in the emergency department in danger," says Tami Morin, the nursing manager of UW Health's ER.

Several years ago, the department instituted a special security plan. When moments get heated, members of the care team conference and can decide to raise the security status level in the ER.

Ceiling lights that tone loudly when they change color let everyone know -- including arriving ambulances -- what the situation is like. A green light means things are okay, but a yellow light indicates there might be an issue. A red light means no visitors will be allowed back into the treatment area, and extra security personnel are brought in, WISC-TV reported.

While the system might sound common sense, UW officials said that they believe it to be very different than what is done at other hospitals. The program was prompted a few years ago by two incidents when a two nurses were moderately injured, requiring them to take time away from work to recover.

Morin said its been very successful.

"Since the security plan was implemented in October of 2007, we have had no lost days of work, and no significant injuries," Morin said.

Both hospitals make use of their own uniformed security staff, which can step into assist. However, nurses at both institutions say just the sight of a person in uniform is enough to calm most out of line patients down.

UW Health is submitting an article about their security procedures to trade publications so other hospitals can benefit, officials said.