| As we spend increasing amounts of time at our | | | | elbow, wrist and hand. Additionally, reaching |
| computer workstations, we need to be aware of | | | | forward for the mouse stresses the lower and |
| how the design and arrangement of our | | | | middle back. |
| equipment can impact our chances of injury. | | | | So How Does Reaching for the Mouse Set the |
| Computer ergonomics is the study and / or | | | | Stage for Injury? |
| implementation of work station design with the | | | | Reaching for the mouse causes you to lean |
| purpose of reducing or eliminating physical stress. | | | | forward in your chair, extend your arm and |
| My interest in repetitive stress syndromes began | | | | support the weight of your body through your |
| approximately 10 years ago when my practice | | | | extended arm. The following section will discuss |
| started seeing a much greater number of people | | | | the particulars of each of these positions. |
| suffering from the effects of computer work. | | | | The stresses placed on the human frame when |
| Despite all of my training and continuing education | | | | reaching for the mouse are easily explained. |
| related to these types of injuries, I quickly realized | | | | Contrary to popular belief, sitting, which most |
| that short of surgery and radical changes in the | | | | people believe is relaxing, is hard on the back. |
| patient's lifestyles, treatment for this type of | | | | Sitting for long periods of time can cause |
| injury was marginally successful at best. | | | | increased pressure on the intervertebral discs of |
| The real solution had to be prevention and it was | | | | the spine. |
| going to involve the application of basic ergonomic | | | | In recent years, ergonomisist have told us that |
| principals. | | | | proper sitting posture would have us sitting upright |
| This article will address the specifics of injury | | | | with our hips flexed at 90 degrees. As it turns |
| resulting from postural stress secondary to use | | | | out, the most up to date studies show that a |
| of the computer mouse. | | | | slightly reclined sitting posture with the hips flexed |
| Specifically, the following will be addressed: | | | | at 100 to 115 degrees is ideal if you have to sit at |
| 1) What repetitive stress injuries are | | | | a desk. If your mouse is not positioned close |
| 2) What role do work station ergonomics play in | | | | enough to your body, you will have to reach for |
| injury | | | | it. Reaching for your mouse stresses your back |
| 3) How reaching for the mouse sets the stage | | | | by reducing the angle of your hips. |
| for injury | | | | Next, we have to look at the effects of reaching |
| 4) What are the symptoms of repetitive stress | | | | on the neck and shoulder. When the mouse is |
| injury | | | | being operated at a distance that makes the |
| 5) How one can avoid mouse reaching injuries | | | | operator reach, the shoulder extends forward and |
| What Exactly is a Repetitive Stress Injury? | | | | the shoulder blade abducts (rotates forward). This |
| Repetitive Stress Injury is a kind of catch all | | | | position stretches the muscle groups that connect |
| phrase for many conditions. Carpal Tunnel | | | | the medial portion of your shoulder blade to your |
| Syndrome, Tenosynovitis / DeQuervain's | | | | spine and the superior portion of your shoulder |
| Syndrome, Tendonitis, Thoracic Outlet Syndrome, | | | | blade to your neck. |
| Trigger Finger, Myofascial Pain Syndrome and | | | | In the short term, this stretch aggravates the |
| Chronic Sprain / Strain are some of the actual | | | | affected muscle groups causing spasm, fatigue, |
| diagnosis that are rendered in my office. All of | | | | headaches and stiffness in the neck and shoulder. |
| these conditions are serious and in many cases | | | | In the long term, this position creates a condition |
| can cause great pain, permanent disability and | | | | called a "stretch weakness" resulting in muscular |
| sometimes loss of employment. | | | | imbalance, trigger points and chronic variations of |
| Repetitive Stress Injuries occur from repetitive | | | | the conditions listed in the prior sentence. |
| movements involving a specific set of muscles | | | | Lastly, placing the mouse too far away, too low, |
| and joints. RSI injuries are the result of an | | | | or too much on one side can cause shoulder, |
| accumulation of stress and strain that causes | | | | wrist, elbow, and forearm discomfort. When the |
| irritation, inflammation, and eventually pain or other | | | | operator is forced to reach for the mouse, his / |
| disability. | | | | her body weight shifts forward and ultimately |
| A good analogy used to characterize the onset of | | | | results in weight bearing stress on the extended |
| RSI would be the "straws on the camels back" | | | | arm. Spending prolonged periods of time leaning |
| saying. | | | | on an extended arm is an unnatural and |
| Initially, RSI affects the soft tissues of the | | | | destructive posture that will eventually lead to the |
| involved joint(s). Soft tissues include muscles, | | | | development of a repetitive stress syndrome; |
| nerves, ligaments and tendons. However, if left | | | | likely resulting disorders would include tendonitis of |
| untreated for long periods of time, the involved | | | | the wrist, elbow or shoulder. |
| joint can become arthritic and form bone spurs | | | | What are the Common Symptoms?o Tightness, |
| resulting in permanent damage to the joint. | | | | discomfort, stiffness, soreness or burning in the |
| While various occupations ranging from meat | | | | hands, wrists, fingers, forearms, or elbowso |
| cutters to construction workers develop RSIs | | | | Tingling, coldness, night pain or numbness in the |
| that result from the typical duties of their | | | | hands, especially around the base of the thumbo |
| professions, the most frequent cause of these | | | | Clumsiness or loss of strength in the handso Pain |
| injuries involve computer work. The constant | | | | in the neck, shoulders, wrists, hands or back that |
| demand of keyboarding and mousing combined | | | | is associated with using the computer |
| with the postural stress of confinement in an | | | | How Can You Avoid Injuries Related to Reaching |
| office chair with one's neck and back held in | | | | for the Mouse? |
| prolonged fixed positions has resulted in an | | | | The following recommendations are applicable to |
| epidemic of injuries that includes hand pain, wrist | | | | both home office ergonomics as well as |
| pain, arm pain, neck pain, back pain and shoulder | | | | ergonomics in the office. |
| pain. | | | | 1) Placing the input device directly in your |
| Work Station Ergonomics | | | | immediate reach zone offers natural comfort and |
| The study of workstation ergonomics tells us that | | | | maximum hand-eye coordination. The use of a |
| the objects that are used most often should be | | | | platform for the mouse is preferable. Some |
| located closest to your body and accessed easily, | | | | models of mouse platforms attach directly to |
| without awkward body positions. Repeated | | | | your chair. |
| reaching or prolonged postures that involve leaning | | | | 2) Your chair should have arm rests that are |
| forward from your chair are particularly stressful | | | | adjustable. |
| and fatiguing. | | | | 3) Your wrist should be either in a neutral position |
| Many people are aware of computer ergonomics | | | | or flexed slightly downward when operating both |
| and thus have an ergonomic mouse. An | | | | your mouse and your keyboard. For this reason, |
| ergonomic mouse is of little use if it is positioned | | | | if you select a mouse platform that attaches to |
| in an area that requires reaching and stretching in | | | | your chair, adjustability of the platform is of |
| order to operate it. Limiting reaching and | | | | primary importance. |
| stretching for desk items is essential to | | | | 4) Consider using a high quality office chair with |
| maintaining a healthy ergonomic environment. | | | | adjustable armrests and lumbar supports. It should |
| The most frequent complaint that I have seen in | | | | also allow some degree of recline. |
| my office is due to computer work is the | | | | 5) Make sure that the upper arm and elbow are |
| combination of mousing and its' inherent postural | | | | as close to the body and as relaxed as possible |
| stress. | | | | for mouse use - avoid overreaching. |
| Most computer stations are designed in a way | | | | 6) Hold the mouse lightly, don't grip it hard or |
| that involves the worker operating the computer | | | | squeeze it. Place the pointing device where you |
| mouse on a pad on the desk. Reaching to the | | | | don't have to reach up or over very far to use it. |
| desk for the mouse places direct stress on the | | | | The closer you can place it to your body the |
| joints and soft tissues of the neck, shoulder, | | | | better. |