Claw Hammer

Does the Weight of a Hammer Matter?

hand tools

Photo: Wikimedia Commons/Maylene Thyssen

In a workplace filled with complex machinery, moving vehicles and power tools, a hand tool like a hammer seems pretty simple, right? To a certain extent that’s true, but in another sense, choosing a hammer isn’t quite so simple. Selecting a hammer requires knowledge of hammers, the task the tool will be used for and your own hand.

A hammer that’s too heavy for a task will quickly tire a worker’s arm, which could lead to muscle strain or harm to nerves. Over time, these problems take a toll on the body and can lead to repetitive motion injuries. A hammer that’s too light, on the other hand, can cause an employee to increase the speed of strikes to get the job done, which can cause similar ergonomic problems.

Additionally, other qualities of a hammer like the material it’s made from and the type of handle it has play a role in worker safety.

In this post we will take a look at work-related musculoskeletal disorders (WMSDs), hammer selection and considerations for selecting other non-electric tools for the workplace.

Common Musculoskeletal Disorders of the Hand & Arm

Before we take a look at how to select a hammer, let’s examine some of the reasons proper tool selection is necessary. Using a tool that’s too heavy or not ergonomic can lead to muscle, tendon or nerve injuries over time. According to the Canadian Centre for Occupational Safety and Health (CCOHS), WMSDs occur because of a combination of factors that include repetitive motion, awkward body postures or hand/arm angles, significant amounts of force being placed on the hands and wrist and a fast work pace without sufficient time for recovery. All of these problems can occur when a worker uses a hammer frequently (or for long periods of time).

White Finger Syndrome, Hand Safety

Raynaud's Syndrome (also known as White Finger Disease) can be the result of using hand tools that vibrate. Photo: Wikimedia Commons/Intermedichbo

Some common WMSDs of the hands and arms include:

  • Carpal Tunnel Syndrome – Probably one of the best-known WMSDs, carpal tunnel syndrome is common among workers who do a lot of computer work. It’s also common, though, among construction workers and workers in industrial facilities. Carpal tunnel occurs when the median nerve (which runs the length of your arm from your palm up your forearm) gets pressed at the wrist. It’s caused by bending the wrist or holding tools tightly and results in burning and tingling sensations in the hands.
  • Raynaud’s Syndrome/White Finger Disease – This syndrome is a problem with the nerves and blood vessels in the hand and it is usually caused by vibration. It can impact workers who use hammers and chisels, and symptoms include pain, numbness, a weakened grip and white fingers (due to restricted blood flow).
  • Thoracic Outlet Syndrome – Workers who do a lot of overhead work are at risk of thoracic outlet syndrome, which involves reduced blood flow to the arm and shoulder. This can lead to pain anywhere between the neck and the hand, as well as numbness or weakness in the hand.
  • Tendonitis – Tendonitis is a common injury that stems from overuse of the tendons, and it can be caused by using hand tools that are too large or too small. Pain, stiffness and swelling can occur in the affected area.

Other WMSDs exist, but these four are common among workers who use hand tools. These syndromes occur frequently among carpenters, electricians, sheet metal workers, construction workers and others.

Prevent WMSDs: Select an Appropriate Hammer

Now we’ll return to our discussion of hammers, as hammers are hand tools that can lead to a number of WMSDs. As mentioned earlier, the weight of a hammer can be either too heavy or too light, so it’s important to select one that is the lightest weight possible that doesn’t cause the user to swing more quickly to compensate for the lighter weight. In general, a hand tool should not exceed 2.2 pounds. Finding the appropriate weight may take some trial and error. Workers should test the weight of a few hammers to find out which feels the best.

Hammers should also be balanced, meaning the handle or the head of the hammer isn’t excessively heavy. ChooseHandSafety.org, a resource for selecting hand tools and gloves, suggests standing the hammer up on its claws to see if it is balanced. If the hammer falls down, it’s handle heavy; if it tilts up onto its head, it’s head heavy.

A few other factors play a role in the overall safety of a hammer, so consider the following:

  • Hammer Material – Tools like hammers and mallets vibrate a lot during use, which can lead to nerve damage and White Finger Syndrome. Choosing a hammer with a wood or fiberglass handle instead of a metal one can reduce the amount of vibration transmitted to the hand.
  • Anti-Slip Grip – Some hammers have anti-slip materials on their handles, which help users grip the hammers more easily. These materials can also result in reduced vibration and less exposure to cold, which both help prevent White Finger Syndrome.
  • Grip Size – The diameter of a hammer’s handle is important because it needs to fit a user’s grip. Determining your grip size and finding a hammer with a suitable handle can reduce injuries.

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Tips for Selecting Other Hand Tools

Using a hammer on occasion at work will likely not lead to a WMSD, but over time using hand tools like hammers inappropriately (or using the wrong kind or size of hammer) can cause trouble. When selecting any tool, workers and employers should assess the task at hand, find the right kind of tool and make sure the tool fits the hand of the person using it. Other tool qualities that should be considered are the angle of the tool’s handle (you’ll want to select a tool angled so that the user can keep his or her wrist straight while using it) and the length of the handle (a handle that’s too short can dig into someone’s palm and cause nerve damage). Further information about tool selection can be found in this blog post or at ChooseHandSafety.org.

Additional WMSD Considerations

wrench, hand tools

Tools that require a power grip (pictured here) can lead to different injuries than tools that require a pinch grip.

Tool users should also keep in mind that different tools may make them more susceptible to different kinds of injuries. Using a hammer, for example, requires a power grip, which is a full-hand grip that uses many large muscles in the arm. The muscles that will get fatigued from using a hammer, then, are different from the muscles that will get fatigued from using a screwdriver. Workers often use a pinch grip (which uses just the fingers) when using a screwdriver, and if this is done at odd angles, carpal tunnel syndrome can occur.

So how can you avoid these syndromes when using hand tools? These tips are a good place to start:

  • Choose tools that aren’t too heavy
  • Always keep your wrist straight when using tools
  • Find tools that fit your hand and grip
  • Take periodic breaks so muscles can recover

Need to store your new tools? Try using foam organizers.