Health and Safety ReportFebruary 2009 - Volume 7, Issue 2

If you are sitting at a desktop computer, chances are you are also using a mouse. That little handheld pointing device changed the way we use computers. Since the introduction of Windows technology in the 1990s, mouse-intensive software has been an unavoidable part of office work. It is an amazing gadget that makes complex tasks "just a click away," however the mouse does have its drawbacks. It requires the small muscles in the user's hand, fingers and thumb to repeat the same precise movements throughout the day, and for office workers this could mean every day.

Using a mouse can cause pain in the hand, wrist, forearm and elbow. Painful nodules and ganglion cysts may form along the joints and tendons. Extended use of the mouse can also cause numbness and tingling in the thumb and index finger, and may develop into Carpal Tunnel Syndrome.

The problem is aggravated when the mouse is in a hard-to-reach position and the user must reach out with the arm in an extended, unsupported position. Continually reaching with the arm and holding it in this position causes soreness and fatigue. This strain can affect the muscles in the upper back, shoulder and neck. Many mouse users also adopt awkward positions and poor posture which can affect the lower back.

TIPS to HELP PREVENT MOUSE PAIN

If the computer mouse causes you any discomfort, try some of these tips and see how your body responds. Solutions will not be the same for everyone but if you are experiencing pain, it's a good idea to investigate alternatives.

Go easy on the wrist. Rather than skate or flick the mouse with the wrist, keep the wrist neutral and let your arm do the work by pivoting at the elbow.

Limit your mouse time. If you must use the mouse, avoid using it for long periods of time. Don't wait for the pain to set in. Take frequent breaks from mousing even when you feel fine.

Aim for an optimal mouse position. Try what works best for you. When sitting relaxed in your chair, lift your mousing hand up, pivot at the elbow until your hand is at or just above elbow level. Your mouse should be positioned somewhere around this point. If this place is over the numeric keypad of your keyboard, try a flat mouse platform (your mouse should be 2.5 to 5 cm or 1 to 2 inches higher than keyboard level and over the numeric keypad on your keyboard if possible). If your mouse platform slopes downward, position it close to the keyboard and keep your wrist in a neutral position. Another option is to position the mouse between yourself and the keyboard, or use a built-in touch pad.

Go easy on the mouse. Don't squeeze it. Hold it loosely in your hand with a relaxed grip.

Keep it clean. The mouse will move more smoothly if you keep the rollers dust-free.

Learn keyboard shortcuts. Any opportunity to type a function on the keyboard rather than click it with the mouse gives those tiny muscles a break and helps maintain circulation to the hand.

Shield your wrist. Wrists are delicate. They have exposed blood vessels near the skin. Nature intended the palm of your hand, and your forearm, to absorb any shock to protect the wrist. If you rest your arm flat on a surface, you'll see a curve that prevents the wrist from direct pressure against the surface. Any direct pressure on the wrist disrupts circulation to the hand and increases the risk of injury.

Don't use a wrist rest. For the reasons stated above, any direct pressure against the wrist is risky.

Let arms move freely. Don't lock the forearms into position by resting them on a soft wrist rest or cushy chair arm. This only encourages the wrist to do all the work.

Go big and flat. Choose a mouse that is flat, not curved, to maintain the natural curve in your forearm that protects your wrist. A larger mouse encourages you to use your arm rather than wrist.

Switch hands. Alternating between the right and left hands, or "load sharing," helps prevent overworking one hand with too much mousing. This simply requires a place for the mouse that works on both sides of the keyboard, and a symmetrical mouse you can use with both your left and right hand.

The best way to avoid injury from the computer mouse, of course, is to avoid using it altogether. Failing that, use it in moderation and try some of these tips. Pain relief might be one less click away.

More information:

Workplace-specific information about using a mouse, CCOHS

Towards Pain Free Mousing, York University

Mouse Tips, Cornell University

WorkSafeBC has issued hazard alerts in response to two incidents that gravely injured one worker and killed another.

In the first incident, a worker at a wood-processing plant in British Columbia was feeding rough lumber into a stripsaw. The employer had instructed workers to feed lumber into the stripsaw from the side. The worker, however, fed the boards through from the end of the infeed table instead, presumably for extra force. But when a board kicked back out of the stripsaw, it broke into three pieces. One piece struck another board on the table, which shot back down and struck the worker. He sustained fatal injuries.

WorkSafeBC recommends the following safe work practices to prevent injury from kickback:

For every machine, employers must perform a risk assessment to determine the most appropriate method of safeguarding for the level of risk. The surest way is to eliminate the hazard or find a substitution (such as using machines instead of humans). Next on the general hierarchy of safeguarding, in order of importance, are:

• Engineering controls - such as effective kickback fingers, barrier guards, two-hand controls or presence-sensing devices;


• Employee awareness of warning signs and labels, computer warnings and other safety alerts;


• Training in safe work and lockout procedures; and


• Personal protective equipment, such as safety eyewear and hearing protection.

Other recommendations are to ensure that workers operating dangerous machinery have the necessary supervision. They must be instructed to report unsafe acts or conditions so that these can be corrected without delay, and to follow established safe work procedures.

In a separate incident, a young worker in a rail yard of a pulp mill was preparing railcars for loading in the warehouse. As he pushed open one of the sliding doors of a railcar, the bottom of which was 1.5 metres (4.5 feet) above ground, it came off its top rail guide and fell forward on top of the worker. The 630-kilogram (1,390-pound) door pinned the worker down under its weight until three workers lifted it off. The worker suffered serious internal injuries and multiple broken bones.

WorkSafeBC recommends that all equipment be inspected before delivery to a worksite. Employers should keep records of all inspections. Any defective or unsafe equipment should be returned to the supplier for repair, or rejected. Suppliers have maintenance records for all equipment they deliver, so employers should ask for those records and notify suppliers of any safety concerns.

Workplaces should follow these safe work practices specific to railcars:

• Inspect doors. Railcar doors must be in good working order, with stops at both ends. Employers should develop and use a railcar inspection checklist.


• Report damage. Supervisors should be notified when a railcar is suspected of being damaged or unsafe.


• Protect from falling doors. It is safest to open railcar doors only in areas where a forklift or other machine can be positioned in front of the door in case it falls off.


• Stand at a safe position. Rather than face railcar doors as they open, workers should instead push the railcar doors away from them, standing to the side to open them. They should keep a close eye on the doors until they have securely and completely stopped.

Read the original alerts from WorkSafeBC:

Kickback

Railcar doors

How can we manage the risks posed by nanoparticles? Help is close at hand. A new guide - the first of its kind in Québec - has been published to help deal with managing the risks associated with synthetic nanoparticles. The best practices guide published jointly by the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), the Commission de la santé et de la sécurité du travail (CSST) and NanoQuébec sets out a prevention strategy for both the workers and researchers who use, manufacture or synthesize nanoparticles.

The authors of the guide cautioned that the knowledge on health and safety risks specific to nanoparticles is still very limited. We do know however that nanoparticles can be more toxic than their equivalent larger-scale chemical counterparts and even when the levels of toxicity and exposure are uncertain, there is enough knowledge to effectively manage the risks.

Best Practices Guide to Synthetic Nanoparticle Risk Management describes the current state of knowledge in the field and makes recommendations for controlling its risk factors to prevent workplace injuries. The guide outlines the health, safety and environmental risks of nanotechnologies, and suggests an approach for evaluating and controlling these risks. It also documents current practices at the international level and identifies which factors should form part of an institutional prevention program.

"The guide does not address every issue associated with nanoparticles. Its merits include recommending a preventive approach for minimizing occupational exposure, suggesting a step-by-step approach and providing concrete examples of applications in industrial settings and research centers," stated Marie Larue, IRSST President and CEO.

Musculoskeletal disorders (MSDs) is a very long name for a group of common, painful injuries and ailments that can affect the muscles, nerves and tendons mostly in the back, legs, shoulders, neck, wrists, hands and joints. Work-related musculoskeletal injuries cause pain and suffering for thousands of workers every year and are the largest source of lost-time worker compensation costs in Canada. These injuries can be caused by work involving repetitive motion, forceful movements, and fixed or awkward body postures that are held for long periods of time. MSDs can progress into crippling disorders that can prevent workers from working or leading normal lives.

With RSI Awareness Day on February 28th, CCOHS' release of two new e-courses to help increase awareness of and prevent MSDs is timely. Officially held on February 29th, the only non-repetitive day on the calendar, RSI Awareness Day is set aside each year to help raise awareness about RSIs and the need for action aimed at prevention, rehabilitation and compensation.

The two e-courses MusculoSkeletal Disorders (MSDs): Awareness and MusculoSkeletal Disorders (MSDs): Prevention help managers, workers, healthcare practitioners, chiropractors, and health and safety professionals learn how to prevent MSDs.

The free, twenty-minute MusculoSkeletal Disorders (MSDs): Awareness course covers the risks associated with repetitive strain or motion injuries - collectively known as MSDs.

MusculoSkeletal Disorders (MSDs): Prevention covers the risk factors of MSDs in more depth, as well as introducing ergonomic controls that can help prevent these injuries. These include: ergonomic aspects of the workstation, work organization, the work environment and recommended safe work practices. The course shows how injuries and illnesses related to poor ergonomic conditions can be prevented by making the workplace and demands of the job fit the capabilities of each individual worker.

All CCOHS courses are developed by subject specialists in the field, and reviewed by representatives from labour, employers and government to ensure the content and approach are unbiased and credible.

Pricing and information on how to register is available on the CCOHS website:

MusculoSkeletal Disorders (MSDs): Awareness

MusculoSkeletal Disorders (MSDs): Prevention