Evaluating handrest effectiveness in reducing employee carpal tunnel syndrome

Carpal Tunnel

Program description

The current program will be utilized to determine if the handrests in use are helping to deter the number of occurrences of carpal tunnel. It is the researcher's belief that the current handrests at said company are not helping to decrease the occurrences of carpal tunnel, and therefore further testing and evaluation is necessary. Further examination will help to determine whether current methods i.e. handrests are helping to ease the symptoms often associated with carpal tunnel or decrease the number of occurrences of employees reporting about carpal tunnel like symptoms. The current program for carpal tunnel prevention has not been properly assessed and is therefore in need of further support to confirm whether current methods are in fact improving the current circumstances.

Goals of program

The goals of the current program are to decrease the number of instances that employees report cases of carpal tunnel or carpal tunnel like symptoms. Another goal of the program is to determine methods that will decrease the number of carpal tunnel events that occur all together among the 300 employees currently with the company. Lastly, another goal of the program is to exam whether the handrests are effective or simply increasing symptoms and occurrences of carpal tunnel.

Purpose of the evaluation

The purpose of the current evaluation is to support whether the handrests (specifically) in use are helping to decrease the number of carpal tunnel or carpal tunnel like symptoms from occurring in the 300 employees issued a handrest. In addition, there is also a need to create a basis for comprehension on how to test whether or not a method is effective within the company concerning issues related to carpal tunnel.

Supporting Research

CTS results from compression of the median nerve at the wrist, resulting in burning, tingling, and eventually pain and weakening. Women are three times more likely to suffer from this syndrome than men. (Messing, Lippel, Demers & Mergler, 2000, p. 29) Increased levels of corticosteroids, particularly cortisol, can lead to increased fluid retention in body tissues. This could be an important risk factor for carpal tunnel syndrome (CTS). (Carayon, Smith & Haims, 1999, p. 644) Musculoskeletal disorders make up the largest portion of reported job-related injuries and illnesses in the United States. (Emanoil, 2000) the National Institutes of Occupational Safety and Health (NIOSH) performed a health hazard evaluation of workers in supermarkets in the early 1990's and found an increased risk of developing carpal tunnel syndrome (CTS) if the checker had worked at the job for 10 or more years or had worked more than 25 hours per week. (Marras, Marklin, Greenspan & Lehman, 1995)

Shivers, Mirka & Kaber (2002), discuss that repetitive, awkward, high-force pinch grip exertions have been related to fatigue, discomfort, and injury to the hand/wrist complex in industrial populations. In a study of sewing machine operators, showed that operators with a history of carpal tunnel syndrome used pinch grips more frequently and that the force used during these pinch grip exertions was greater than that employed by the control group (women performing the same jobs at the time that the case group members reported their symptoms). The effects of pinch grip exertions on the intrinsic muscles of the hand were considered in a study of employees in a garment shop. They found a positive correlation between pinch grip duration and hand pain in this population.

Emanoil (2000), discusses research that found that subjects using the vertical split keyboard kept their wrist angles and forearm movements in the lowest risk zone for carpal tunnel syndrome 71% and 78% of the time, respectively. When typing on traditional keyboards, subjects were in the lowest risk zone only 44 and 25% of the time. Wrists were in the highest risk zone only 2% of the time when using the vertical split keyboard compared with 12% with the traditional keyboard. (p. 13) Increased extensor activity, combined with wrist extension, may also increase carpal tunnel pressures. This may be intensified given the flexor tendon loading to depress the keys and increasing the carpal tunnel pressure as well. (Keir & Wells, 2002) research suggest that the specific interaction between a worker's body and tool use may be important, since pressure on the carpal tunnel from work tools is affected by this interaction " (Messing, Lippel, Demers & Mergler, 2000, p. 31)

Another study that Emanoil discussed compared an oversized, flat, and adjustable computer mouse with a built-in palm support with a smaller, contoured mouse device. Researchers measured the wrist extensions and hand movements of 24 men and women while they used the different mouse devices to move the cursor position and to scroll on the computer. Subjects also rated the smaller and larger mouse devices for comfort. The researchers found that the larger mouse reduced wrist extension by an average of more than eight degrees. At high levels, wrist extension can lead to carpal tunnel syndrome. The adjustability of the larger mouse also kept subjects from making small hand movements, such as flicking their wrists, which could increase their risk of injury. (Emanoil, 2000, p. 13)

The aim of this study was to perform a comprehensive investigation to document wrist and forearm postures of users of conventional computer keyboards. Researchers instrumented 90 healthy, experienced clerical workers with electromechanical goniometers to measure wrist and forearm position and range of motion for both upper extremities while typing. For an alphabetic typing task, the left wrist showed significantly greater (p [less than].01) mean ulnar deviation (15.0[degrees] [plus or minus] 7.7[degrees]) and extension (21.2[degrees] [plus or minus] 8.8[degrees]) than the right wrist (10.1[degrees] [plus or minus] 7.2[degrees] and 17.0[degrees] [plus or minus] 7.4[degrees] for ulnar deviation and extension, respectively). On the other hand, the right forearm had greater mean pronation (65.6[degrees] [plus or minus] 8.3[degrees]) than the left forearm (62.2[degrees] [plus or minus] 10.6[degrees]). Researchers further noted minimal functional differences in the postures of the wrists and forearms between alphabetic and alphanumeric typing tasks. Ergonomists should consider the statistically significant and probable practical difference in wrist and forearm posture between the left and right hand in ergonomic interventions in the office and in the design of computer keyboards. Actual or potential applications of this research include guiding the design of new computer keyboards. (Simoneau, Marklin & Monroe, 1999, p. 413)

Considering previous research conducted, it appears that deviated wrist posture in the flexion/extension plane is implicated in the etiology of work-related musculoskeletal disorders (WMSDs) of the wrist. Studies measuring carpal tunnel pressure have shown that carpal tunnel pressure decreases as the wrist moves toward a neutral posture in the flexion/extension plane. Less pressure in the carpal tunnel is beneficial because the median nerve, which passes through the carpal tunnel, is under less compression and is less likely to show the symptoms of carpal tunnel syndrome. In theory if a typist were to type on a negatively sloped keyboard with a wrist extension angle closer to a neutral posture than the approximately 200 extension with a conventional keyboard, then the typist would be less susceptible to WMSDs. (Simoneau & Marklin, 2001, p. 287)

Budget (Estimation)

Estimated Cost

Copies of 300+ questionnaires.16 each @ $48.00

Folding of 300+ copies.03 each @ $09.00

30# paper @ 300 sheets.03 each @ $9.00

Compensation for interview time (per employee) the rate of 1 hour sessions @85 participants

35.00 each @ $2,975.00

Compensation for evaluator time (per employee) during interview process @85 participants

35.00 each@ $2,975.00

Various supplies to include writing instruments, etc.

Compensation for evaluation of -- each @ $150.00

TOTAL ESTIMATED EXPENSE

APPENDICES 1

Questionnaire

Current job function:

Do you use a computer regularly?

Do you use the handrest provided by the company regularly?

How many hour non-stop do you use your hand rest in conjunction with computer use?

Do you have frequent burning, tingling, weakness, or numbness in the palm of the hand and the fingers? (especially the thumb and the index and middle fingers)

Do you fingers feel swollen?

If you have experienced burning, tingling etc. when did symptoms first occur?

Have you ever awaken in the middle of the night with numbness or pain in the wrist and hand?

Have you experienced a decrease in ability to grip objects, or perform labor-intensive tasks?

Have you lost the ability to decipher between varying temperatures of hot and cold?

Have you experienced numbness or pain in your hand, forearm, or wrist that awakens you at night?

Occasional tingling, numbness, "pins-and-needles" sensation, or pain. The feeling is similar to your hand "falling asleep."

Numbness or pain that gets worse while you are using your hand or wrist, especially when gripping an object with your hand or bending (flexing) your wrist.

Occasional aching pain in your forearm between your elbow and wrist.

Have you had stiffness in your fingers when you get up in the morning?

Do simple hand movements, such as brushing your teeth or holding a fork give you difficulty and pain in the wrist and hands?

Is it difficult to pinch items between your thumb and pointer finger?

Is it difficult to use your thumb while doing simple tasks such as opening a jar or using a hammer or screwdriver?