Ergonomics Essay, Research Paper
Do you dread sitting at your desk all day? Does your body ache after work? If so, you are not alone. Every year thousands of computer users complain about pain in their necks, backs, legs, shoulders, elbows, and wrists. As more people use the computer for work, education and recreation-, the number of computer-related injuries increases. A broad name for the majority of these computer-related injuries is Cumulative Trauma Disorder (CTD) also known as Repetitive Stress Injury (RSI). According to the U.S. Bureau of Labor Statistics, Repetitive Stress Injuries account for more than half of all work-related injuries (Graps). You can prevent CTD or RSI if you know the symptoms and causes of these injuries, by making ergonomic purchases and maintaining the proper posture.
Computer injuries such as, CTD and RSI are commonly overlooked as minor injuries; when in actuality these injuries can be very severe and dramatic. Cumulative Trauma Disorder and Repetitive Stress Injuries are broad terms for all injuries resulting from placing too much repetitive stress on a joint – pulling on the tendons and muscles around the joint (Protecting Your Child?). The repetitive stress can be due to the lack of physical fitness, tension, stress, individual work habits, long hours, lack of breaks, bad ergonomics, and poor posture. The injuries can include but are not limited to the following conditions described on EGO’s Ergonomic Manual, KidsHealth.org, and HealthTouch.com:
? Carpal Tunnel Syndrome – when the nerves running through your wrist into your fingers are trapped by the inflamed tendons around them. Symptoms include feeling “pins and needles”, tingling, numbness and loss of sensation, pain or aching hands and arms, and eventually loss of coordination and grip strength.
? Cervical Radiculopathy – disk compression in the neck, often caused by repetitive cradling of the telephone on the shoulder.
? Tendonitis – an inflammation of a tendon. Repeated tensing of a tendon can cause inflammation. Eventually, the fiber of the tendon start separating, and can even break, leaving behind debris which induces more friction, more swelling, and more pain. Symptoms entail a dull ache over the wrist and forearm, some tenderness, and gets worse with the repetitive activity.
? Bursitis – the inflammation of a bursa. Bursas are small sacs located between bones and other moving structures such as, muscles, skin, or tendons. Bursas allow smooth gliding between these structures. When the sac is inflamed or irritated, swelling, pain and stiffness will occur. Bursitis and Tendonitis can affect the shoulder, elbow, wrist, finger, hip, knee, ankle, and feet.
? Ganglion cyst – swelling of a lump in the wrist resulting from a jelly-like substance leaking from a joint or tendon sheath.
? Reflex Sympathetic Dystrophy – rare, incurable condition characterized by dry, swollen hands and loss of muscle control; consistently painful.
One of the greatest risk factors leading to RSI is the restriction of circulation. When you extend your arms out to the side at shoulder level, the circulation is poor. When you use all the oxygen in the bloodstream, you begin to ache, loose strength and must put your arms to rest. This same thing happens during repetitive contractions like computing. During computing our tissues need all the oxygen and nutrients possible. When the bloodstream (circulation) is constricted from inflammation the tissues do not get the needed nutrients or remove the waste products (lactic acid and carbon dioxide) that build-up and cause more pain (Graps). To ensure you have good blood circulation become more ergonomic and improve your posture.
The improvements in the fields of science and technology are providing new ergonomic products for computer users. These products help computer users be more ergonomic-making equipment use less fatiguing and more comfortable. Ergonomic products prevent the discomfort resulting from operating the computer. Some of the most marketed ergonomic products include the mouse, split keyboard, chair, wrist rest and footrest. Although, using these products can help prevent computer-related injuries, these products typically are expensive. The more economical way to prevent computer-related injuries is to practice perfect posture.
Perfect posture is the neutral position of our body. This is the position that places the least amount of pressure on all of our joints and muscles. To achieve perfect posture when you are standing, you should be able to draw a straight line from ear to ankle. When sitting you should be able to draw a line perpendicular to the floor from your ear through your elbow to your hip. When sitting, the spine and limbs should remain in their neutral positions. To prevent computer-related injuries, follow these posture guidelines for 1) Head and Neck, 2) Spine, 3) Shoulders, Elbows and Wrists, and 4) Legs and Feet. After reading about the importance of good posture, look at Diagram 1: Perfect Posture.
Head and Neck
The position of your head in relation to your body and the computer is the main concern. The slight inward curve of the neck balances the head on the spine. Holding the head foreword disturbs this balance, straining the joints and muscles of the neck and upper back. This posture causes compression of the nerves and blood vessels as they exit the neck, leading to symptoms in the arm and hand (A Patient’s Guide?). Your head should rest directly over your shoulders without straining either forward or backward. The top of the monitor should be positioned level with your forehead so you are looking slightly down- no more than 30? (Good Posture Prevents?). If the monitor is too high or low, try adjusting the chair or sitting on a book.
The spine consists of three segments the neck or cervical, the chest or thorax, and the lower back or lumbar. The cervical region was discussed above and is just as important as the thoracic and lumbar regions. To prevent your spine from twisting, your computer keyboard and monitor should be directly in front of you. Your back should be upright, arching slightly foreword at the hips, but maintaining contact with the chair. The easiest way to achieve this position is to sit with the back of your knees at the edge of the chair while having the chair support your lumbar. Do not slouch in your chair, or lean over the keyboard. These are bad habits which can create prolong injuries. Slouching forward compresses the chest cavity or thoracic region, which prevents the diaphragm muscle from completely filling the lungs with air. Decreasing the oxygen circulation causes the body to be fatigue and the mind to loose concentration.
The position of the lumbar affects the entire spine, thus it is important to maintain good lumbar posture. When sitting a properly designed chair will support the lumbar and have a seat long enough for the thighs. Avoid over arching or straightening the lumbar spine, this will force the thoracic and cervical regions out of the neutral alignment.
Shoulders, Elbows and Wrists
The shoulders also play a very important role in attaining perfect posture. Keep your shoulders back, chest out. If you tend to shrug your shoulders, you may need to get closer to the keyboard. The rolling of the shoulders also collapses the thoracic region of the spine, which creates poor blood circulation. To prevent this from happening, keep your shoulders back. You should also keep your elbows close to your side. Many people get shoulder pain not because the do not sit straight, but because they are constantly reaching for the keyboard or mouse. Keep your elbows at your side directly under your shoulders at a 90? angle. If needed adjust the height of the chair to enable you to form a 90? angle with your arms at your side with your fingers on the keyboard. Wrists should remain as straight and neutral as possible. Avoid flexing your wrists up, down, or to either side. Never rest your wrists on the keyboard; use your lap instead. The repetitive wrist resting can damage nerves at the contact point between wrist and keyboard.
Legs and Feet
It seems so odd that the position of your legs and feet could make such a difference in your posture, your pain and your productivity. When computing your thighs should form a 90? angle with your spine, and be parallel to the floor. Adjust the chair or add a footrest to make your thighs parallel to the floor while maintaining the correct head and neck posture. If your legs are forming less than a 90? angle with your thighs, you will tend to round your shoulders, collapse your thorax and cause poor blood circulation. When your legs form an angle greater than 90?, you will slouch in your chair and extend your neck foreword. This posture can depress the discs in your back. Your feet should be flat on the ground or footrest, do not let feet dangle in mid-air. Avoid crossing your legs at your knees. This causes more strain on the back because the spine is unbalanced and not in the neutral position.