From The Ergoweb® Learning Center


Dan MacLeod, CPE, MA, MPH

Principles affected

Related pages



The triggers on some power tools, especially older models, have been found to require too much strain on the trigger finger, resulting in injury and fatigue.


Minimize force as appropriate to the task. Minimize pressure points.

Ideas and Options

Pull force






Trigger locks


Full hand triggers

Full hand trigger FullHand2
Full hand triggers for high force

A full hand trigger provides a good option for tools that involve heavy force. This style simultaneously distributes the load among all fingers and allows the full hand to help manipulate the tool itself.

A shortcoming of this style is some loss of control of the grip when the full hand is opened to release the trigger. Consequently, this full hand triggers are usually used in conjunction with a second handle or a hand strap.

Multiple finger

Thumb triggers

Palm triggers


Engagement triggers