Usually, Ergonomic Causes of disorders is the out come of the alignment between the user and the computer components and accessory devices which is not proper. This makes it difficult for the user to maintain good postures, such as straight wrists, elbows close to the body, and head straight and in -line with the torso. Let’s see a few instances that we face in our everyday life to which Ergonomic Causes occurred out of such misalignment:
- When your monitor is positioned too high, you tend to tilt your head back, which fatigues the neck and shoulder muscles.
- If your keyboard tray is too small, you tend to move the mouse to a position of the desk that requires you to reach to perform mouse tasks. This pulls the elbow away from the body and can cause you to support your arm in an elevated position for prolonged hours leading to discomfort and fatigue.
- If your keyboard is too low, you tend to bend your wrists at extreme angles, which can cause the finger tendons and tendon sheaths to bend around the bones of the wrist. Sitting in such awkward postures irritate or strain the bone-tendon-muscle connections.
- Muscles when stretched or compressed become inefficient resulting in possible fatigue and overexertion.
- Postures that are not neutral ones can pull and stretch tendons, blood vessels, and nerves over ligaments or bone thus increasing their chances of becoming pinched and restricted.
- Tendons and their sheaths can rub on bone and ligaments leading to irritation and fraying. This in turn leads to swelling within confined areas such as the carpal tunnel, which then restricts nerves and blood vessels.
- The user may also suffer from tingling and numbness of the fingers and hands as well as pain from tendonitis and tenosynovitis (inflammation of a tendon sheath). If the workstation is properly adjusted, it can help the users to minimize awkward postures. It is ideal to place the monitor in front of you at a height where you can look straight ahead and not tilt your head forward or backward. You can keep the items that you access frequently such as keyboards (Ergonomic Keyboard) and pointing devices very near to you so that you don’t have to strain yourself while reaching out for them every time. You need to adjust and position keyboard trays and chairs so that you don’t have to bend your wrists up, down, or to the side. Adjust the chair so as to give good support to your feet and back. If you maintain proper neutral postures, you can work with minimal stress on the musculoskeletal system.
Ergonomic causes: Contact Stress
There are two types of contact stress type of Ergonomic causes- internal and external. When a tendon, nerve, or blood vessel is stretched or bent around a bone or tendon, you suffer from internal contact stress. When a part of your body rubs against a component or device in the workstation, like chair seat pan or the desk edge, you are said to be suffering from external contact stress. This may lead to irritation of the nerves or contraction of the blood vessels.
- The users experience contact stress to their forearms when they rest them on the leading edges of worktables or, if the nerves in the forearm are affected, their fingers and hands may tingle and feel numb, similar to the feeling when they hit their “funny bone”.
- If blood circulation is cut off by contact with the leading edge of a chair, the users are sure to experience pain and numbness in their legs.
- The forearms and wrists can be affected if the edges of the wrist rests are sharp and hard leading edges.
- If the wrist is kept bent throughout the jobs like typing which is a repetitive finger motion task, the tendons are sure to get damaged.
You can solve such Ergonomic causes by carefully selecting wrist rests, chairs, and desk surfaces as well as by taking frequent rest and stretch breaks to minimize the amount of contact stress that you may experience. Your workstation should be adjusted in such a way as to maintain neutral wrist postures.
Ergonomic causes: Force
Usually, when we talk about force, it is thought of as a strenuous physical exertion, such as when lifting a heavy weight or pushing a heavy load. In computer parlance, force is totally different from the usual definition. Computer work seldom requires this type of laborious exertion, but there are tasks that require concentrated force that can affect smaller, localized muscle groups.
1) Pretend you are using a pointing device that is too sensitive that you find it so difficult to control leading to a Ergonomic causes. There are all chances that your finger and forearm muscles become sore because the muscles of hand and arm must work hard continually to keep the device steady.
2) Pretend your mouse is placed very far from you that you have difficulty reaching for it every time. This time what really happens is that your shoulder and neck muscles become strained as they are continually being used to lift the arm away from your body.
3) Pretend your monitor is kept very high from the recommended height. You tend to tilt your head back to get a clear view of the monitor. This time the muscles of your back can become strained due to continued use.
Normally, when injuries happen, the first point of pain is the muscle. But, the tendon, which attaches the muscle to bone, can also be affected. Localized pain, stiffness, and tenderness are some of the symptoms showing that the muscle or tendon has been exerted beyond its capacity. If you arrange the computer and associated components in your workstation properly and appropriately, so as to maintain neutral postures, you can avoid such problems to a large extend. Select adjustable furniture so that you can minimize the amount of time spent in one posture.