Uniquely among the main care disciplines, mental health services routinely have to manage a triangle of potentially violent relationships: patients attacking staff, patients attacking each other and - when it comes to restraining aggression - staff using force on patients.
A decade ago the death of schizophrenia patient David Bennett after being held face-down by five staff sparked a national debate about restraint procedures.
But, as HSJ reveals this week, the urgent proposals which emerged are still waiting for funding.
The Department of Health has left a national training scheme for staff in acute mental health wards on hold, and now a report by the Healthcare Commission and Royal College of Psychiatrists shows acute ward violence is on the increase while many staff are still untrained.
This is not just about patient safety. The government says it is committed to protecting staff from assault, but that does not just mean drunks in accident and emergency. Many mental health workers are at risk through inadequate training.
The DH needs to act before another patient or staff member is killed.