It is higher pay to any worker that would have been injured without it. Once they reach that point in time when an injury would have occurred, they are then receiving more pay than they would have if the injury occurred.

We shouldn't stop the comparison of pay at the moment a person is injured. These are people, they don't stop existing the moment they aren't useful to a company. And an injury does effectively reduce their pay by preventing them from working, or forcing them to change careers.

This is a safety device, and no productivity improvements have been shown yet. So you wouldn't expect an outright increase in hourly wages. But an increase in working years without injury is a benefit to workers, and does increase their lifetime earnings.