If you use a drill or screw gun for overhead work, you are forced to keep your arms and neck in fxed, awkward, hard-to-hold positions. You have to push upward with a heavy tool above your shoulders, using your shoulder muscles instead of your biceps.  This work can put stress on your arms, neck, shoulders, and back. It can lead to fatigue and serious muscle or joint injuries.

The photo on the left shows the problem, while the photo on the right illustrates the solution.

More Detail

You strain your arms, neck, shoulders, and back less because you don’t have to hold the tool above your shoulders or work in an awkward position. You work with your upper arms held close to your sides, and your hands in front of your body. You are pushing with your biceps muscles instead of your shoulders.

Quality of Evidence

• Independent published studies have found a risk reduction.

Studies have documented reduced forces and reduced muscle strain when using a bit extension instead of holding the drill overhead which over time will reduce musculoskeletal injuries.  Overhead drilling usually involves working from a step ladder, so this may reduce fall hazards as well.

Bit extensions should reduce a worker’s chance of developing muscle and joint injuries. Workers beneft from not having to hold a heavy tool above their shoulders for long periods. The extension itself weighs less than two pounds. Using the extension is easy after a little practice. One company that uses the extensions says that their workers like the way the extension prevents shoulder strain.

However, an extension does not solve the problems caused by holding your neck tilted back to look up at your work. To cut down on neck strain, avoid looking up when you don’t have to. To be safe, make sure you push the extension onto the drill chuck tightly, before you turn on the power. In a screw gun, the screw must also be tight in the bit.

Quality of Evidence

• Safety and health experts believe there is an increase in productivity.

Holding a heavy drill over your head for extended periods is extremely fatiguing.  To the extent that a bit extension reduces the effort involved in this task, it is expected that this will reduce rest intervals and increase productivity.  Where more of the work can be done from the floor rather than from a step ladder or scaffold, it is expected that productivity will be improved both because working from the floor is easier and time for moving from one location to another will be reduced.

Equipment like that described here may be available from local retailers or rental companies.

Approximate Cost

You can make your own bit extension, which will cost $1-2 for materials plus your time.  Manufactured bit extensions cost from approximately $12 for a 12-inch model to $45 for a 24-inch model.