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Updated 09 December 2015

Ergonomics

When mankind first began to use tools and implements to hunt and gather, the seeds of ergonomics were sown.

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When mankind first began to use tools and implements to hunt and gather, the seeds of ergonomics were sown. Flintstones, metal tools, weapons, and clubs all were crudely designed to be held easily, welded dexterously and worked with comfortably.

Ergonomics is the science of matching the task at hand and particularly the machinery and tools used to perform the required task, to the human anatomy. The mistake often made is for machine and implement designers to design without allowing for the nuances of human anatomy. It is not only the machine design that is crucial but also the workflow. Often the machinery and tools are not able to be adapted; the process demands a particular fit.

In this case the creativity to prevent injury is to adapt the workflow – rotate employees though different alternative tasks, train others to multitask and to share the load. This lessens the insult and trauma to the musculature. You may choose to do only one task for lazy and self-serving reasons, yet this will over time strain and injure important tendons, ligaments and muscles. Repetition, consistent strain and stress cause inflammation, tearing of tendons and fractures.

Machines must be adapted to humans
We, the human machine should not have to adapt ourselves to the ingeniously designed tool; the design should allow for the fat and the thin, both tall and short, male and female, left and right handed. In other words we should not have to adapt to the machine but the machine to us.

When we adopt awkward postures, bend and squat unsafely, grasp uncomfortably and repetitively use our wrists and arms to lift, push, pull and twist, we put our health at risk.

American statistics report that 1.8 million workers suffer a musculoskeletal injury annually. Most industrialised countries, of which South Africa is one, encourage, if not legislate that the employer must conduct an assessment of the risk to the health and safety of workers including ergonomic risk. Poor ergonomics can lead to injury, workers' compensation costs, medical aid bills, absenteeism and lost productivity.

The factory employee, machine operator, packer, fitter and mechanic all work daily with awkward, and at times heavy tools and machinery. They have to bend, squat, twist, push, pull and lift. Injuries do occur. Some immediately, but many only after months if not years of daily ergonomic stress and strain on the muscles, tendons, ligaments and vertebra of the neck, back, shoulders and arms.

Common injuries
Common injuries are strained and stiff necks, pain when looking up and down and side to side; stiff, painful shoulders especially when lifting an outstretched arm upwards, a frozen shoulder; a painful elbow when lifting an article with an outstretched arm, a tennis or golfer's elbow; a painful forearm, wrists, numb fingers with pins and needles - tendonitis, tendinosis, carpal tunnel; numerous back-related maladies coming in all forms and guises, knee problems, heel problems and numerous other torturous injuries.

On the factory floor use gloves with a good grip; use them when lifting machinery; pick up fewer articles at a time; use handles to make gripping easier; enlarge grip size and push rather than pull. Adapt the work piece and the work area, as is possible, to allow your body to maintain an unstrained and comfortable position with arms, forearms and shoulders relaxed.

It is expected that the hardworking factory floor employees will suffer injury, yet the office worker,” sitting all day, in a comfortable chair, in a ventilated, heated or cooled environment” is also at risk. Ironically it is the ergonomic injuries sustained by the office worker which highlighted the injuries sustained by employees from ergonomic stresses and strains.

Sitting all day, in a poorly-designed chair, which is at an incorrect height at a cramped and cluttered workstation can cause awkward postures to be adopted; these include over-stretched and stooped angles, tilted necks and angulated wrists. Often these workers sit at strained angles all day, while punching in data, and this could lead to significant injury.

Injuries are often exactly the same as are seen on the factory floor.

3 office-related injuries
Common office-related injuries are Carpal Tunnel, De Quervains and neck pain.

Carpal Tunnel syndrome is a condition involving damage to the median nerve. This very important nerve passes along with tendons through a canal made of bones and ligaments in the wrist called the Carpal Tunnel. This tunnel has very little space to accommodate any swelling. Inflammation of the tendons results in all the pain and suffering associated with Carpal Tunnel Syndrome. The swelling results in pressure on the nerve and this causes numbness, tingling and weakness of the fingers and thumbs. The work actions that can lead to Carpal Tunnel Syndrome include repetitive or awkward wrist movements, continuous finger movements - both of which are regularly experienced by the office worker. Treatment includes removal from the work, rest, splints, cortisone injections, anti-inflammatory medication physiotherapy and surgery.

Excessive typing and strain can also contribute to tendonitis of the thumb, commonly referred to as De Quervain's – this is an inflammation of the tendons of the thumb as they pass over the wrist. This leads to pain with movements of the wrist or thumb. Workers who spend time with keyboards or adding machines are most susceptible to this disease. Through better posture and positioning, rest and ice applications, patients can recover. Treatment is similar for Carpal Tunnel.

Neck and shoulder pain will be experienced by all office workers some time during their work. Stress can cause stiffness and headaches, but recurring pain may be the result of poor posture.  Working at a desk means sitting back on your chair with the back rounded and the head and neck thrust forward. This posture greatly increases the load on the muscles of the neck and the upper back. This can lead to fatigue and pain in the neck as well as headaches.

Relieving muscle stress
To relieve this try to assume a comfortable, yet healthy, sitting position and lift the chest high, allowing the head and shoulders to fall into proper alignment. A gentle nodding of the head 15 degrees upward and downward can also release tension in the neck and back. It is recommended to avoid “neck rolls”, because these movements can pinch nerves and cause additional complications. Gentle stretches instead of swift, jerking movements are easier on the body. To benefit from the exercises, hold the stretches for 5 to 10 seconds, rather than constantly rolling the neck.

Positioning the computer terminal to a higher location on the desk will prevent constant downward strain on the neck. Proper positioning of the keyboard can also minimise stress to the wrists and hands. As you type, the wrists should be straight with the forearms resting on the desk and the fingers should operate with minimal movements of the wrists. Get hold of quick-to-read guides for a safe and healthy work station.

Of interest are recent studies that contradict what our teachers told us – slouching is allowed as it is the body adopting its most comfortable and safest position!

Being informed about ergonomics is essential to protect your musculoskeletal system from unwarranted illness and injury.

 
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