Arthur Saltzman, Ph.D.
Prepared for presentation at:
A study was initiated in April 1997 in order to measure the impact of using an ergonomic software program that was developed by the author called Stretch Break. This program periodically interrupts computer users with an invitation to stretch along with animations on the screen. Each stretch session consists of several stretches, which together last only a minute or two. Then the PC operator is returned to the previous Windows program that was in operation.
Computer operators, who had been using the program for an average of 15 weeks, were asked to report their experiences with Stretch Break by completing a computer-assisted questionnaire. The survey asked users their opinion about the impact of the software, how long and how often they used the program, as well as some demographic questions.
When typewriters were the mainstay in the office environment, typists had more opportunities for physical movement than they do now while sitting in front of a computer. PC operators have very little required motion except for the very repetitive movements of their fingers and hands. There's no need for the change in hand position and movement to push the typewriter carriage at the end of each line. This lack of movement is one cause of the large number of computer operators that report painful musculoskeletal stresses.
In response to the increased incidence of Repetitive Stress Injuries (RSIs), and especially Carpal Tunnel Syndrome, a variety of mechanical devices have been developed (Oldenburg 1997; Magid 1997; CTD News 1997). They range from gloves to a multitude of workplace hardware aimed at insuring the proper placement of the operator and his/her equipment. Another set of solutions involves proper management of the work, so that the operator takes breaks to exercise and stretch and does not spend long periods of time in one position (Henning et. al. 1996, 1994, and 1989; Swanson et. al. 1989; Lee et. al. 1991 and 1992; Thomas, et. al. 1993). In this category are a variety of software programs that remind the computer operator to take frequent mini breaks. Many major corporations are adopting these workplace interventions. A large motivator is the potential for a reduction in the incidence of RSIs.
A search of the Internet reveals many of these software programs that are offered in a variety of configurations. A popular source of information is the typing FAQ (Frequently Asked Questions) that is available at (http://www.tifaq.org/). This source lists over 25 software programs that are oriented towards reminding computer operators to stop and do some physical exercises or stretches. Two other web sites on ergonomics (http://www.engr.unl.edu/ee/eeshop/rsi.html and http://www.ergoweb.com/) list several additional stretching programs.
While some of the publishers of these programs make claims about how much improvement will result from using their products, no research is presented to substantiate any of these claims. Anecdotal evidence from a variety of health-care professionals, as well as testimonials from many users of the programs abound. But there are no surveys on effectiveness, nor is there sound research to show that the programs result in lower instances of repetitive stress injuries.
There is good reason for this. Conclusive research takes time and abundant funds. The ultimate test of the worthiness of a program is whether it results in fewer injuries. To conduct such a test would require a relatively large sample of operators that use a program and another control group that did not used the program. The ultimate statistic would be a comparison of the incidence rates of repetitive stress injuries among the two groups. This is an expensive and lengthy process that hopefully will be conducted in the future. There was some mention of such a study being conducted by a faculty member of the University of Toronto, (http://www.computercare.com/rsi/medical.htm), but the results are not yet available.
Until the time when this type of larger study is performed, the current research provides an intermediary step to provide some empirical evidence on the effectiveness of one of these stretch programs. The current project focuses on the computer operators' assessment of how well the program has accomplished its purposes.
Data collection was accomplished using a disk based survey. With this technique the computer operator inserts a disk that contains a questionnaire into the drive. The questions appear on-screen enabling the operator to use the keyboard and mouse to answer the survey. Because all of the operators had access to a personal computer this was an effective means of collecting data, permitting operators to take the survey at a time of their own choosing. It also provided anonymity.
Although this research design seemed to maximize the ease of administering the survey by using the disk, it still proved to be difficult to collect the data. Some companies that were using the software program were reluctant for a variety reasons. One cited a concern about the possibility of introducing viruses. Many companies do not allow their operators to bring in their own programs on disk. We were able to secure the cooperation of three organizations that had a substantial number of the Stretch Break program installed under multi-user site licenses. The survey disks were sent out to administrative personnel of these organizations. They, in turn, distributed them to the computer operators. After completion of the questionnaires, the disks were sent back to the researchers for analysis of the data.
Each organization that agreed to participate in the survey indicated an interest in determining the effectiveness of the program. They were promised a copy of the project report. Nevertheless, the level of cooperation that we received was low. Of the seven companies that received copies of the disks, three eventually returned some of the disks to us. These included a department in city government, a military base, and a utility provider. The number of returned questionnaire disks from each organization is indicated in Table 1 below.
In conversations with the contact persons we learned that a company may buy a site license for a specific number of workstations but may not implement them for several months. For example, one company had purchased a site license for 100 workstations but there were only 60 currently being used. We sent them 60 disks. Thirty-nine of these were returned, but only 22 contained usable data. This program assessment was clearly not a priority for the persons we contacted.
The data derived from this surveyed is recorded below in several sections. The first section describes the demographic characteristics of the respondents. The second section provides their computer use characteristics. Then comes program utilization, and finally we present the respondent's opinion of the program's effectiveness.
Characteristics of the Sample
The gender, age, and education of the respondents are reported in Table 2. Slightly more than half are female and the median age is 41-45 years. Over 81% have some college or technical school training.
Program and Computer Use
In Table 3 we review information on their use of the stretching program and their expertise with computers. Seventy-five percent said that they were currently using the program. These operators indicated that they have been using the stretching program for an average of 15 weeks. They reported that the program interrupted them to show the stretches on an average of once every 45.3 minutes. This is a longer interval between stretches than the default of 30 minutes, indicating that many of them had modified the length of time between stretches. They indicated that there were approximately three stretches shown during each session, which is the program default. Their computer skill level was relatively high: 88 percent said that they were fairly competent or better.
Experience with software indicates that there are many "periodic" users that will use a software program under certain circumstances and make less use of it or not use it at all under other conditions. So we decided to see if the PC operators used it more or less when they were busy than during a normal day?
When the program starts it asks the user to select from the following options:
CANCEL THIS STRETCH
DELAY FOR 1 MINUTE
DELAY FOR 5 MINUTES
Operators were asked to estimate the percent of time they selected each of these options on a normal day and then on a busy day. The data in Table 4 indicates a major difference between types of days. They were almost twice as likely to cancel the program on their busy days.
While we expected there to be some differences, the magnitude of the gap in utilization of the program between busy and normal days is surprisingly large. One design consideration for this type of software is whether to immediately start showing the stretches at the designated time without giving the operator the opportunity to cancel, or whether permission should be asked first. The data indicates that voluntary compliance leads to decreased usage of the program on busy days, but even on these days it is being utilized about one third of the time.
The primary focus of this study was to determine if the program was effective in reducing stress and musculoskeletal impacts. We also wanted to know if the software affected productivity and attitude toward the job. A related concern was the educational benefits of the program.
To assess these impacts we asked the PC users how much they agreed with a series of attitudinal statements. Their opinions were registered on an analog scale that allows the interviewee to use the mouse to place the pointer anywhere along a virtually continuous scale ranging from Strongly Disagree to Strongly Agree. The pointer began in the middle at Neutral. The data is recorded as a one for Strongly Disagree, 21 for Neutral, and 41 for Strongly Agree.
As seen in Table 5, the operators' evaluation of the software program was very favorable. Operators reported reduced stress and also reduced stiffness and muscle ache. The results indicated that the program produced substantially higher awareness of the need to take frequent breaks and the importance of setting up their keyboard and monitor correctly. There was a moderately positive evaluation of the impact of the program on job satisfaction and productivity.
Program Effectiveness by Primary Task
Stretch Break was designed with particular concern for those who sit for many hours typing at a computer, such as data entry operators. Therefore, it seemed appropriate to see if the responses of those whose primary task was data entry differed from the others in our sample. Data entry was the primary task for 37% of our sample; these were evenly divided between men and women.
As Table 6 shows, those with data entry as their primary task had greater appreciation for the stretching program than those whose primary task was NOT data entry. The ratings of the data entry group were 4 to 7 points higher on the analog scale than the others. The difference is especially pronounced for the last two statements in Table 6. While those whose primary task was NOT data entry were neutral about whether Stretch Break enhanced their productivity and enjoyment of their work, data entry operators felt that they were definitely more productive and their work decidedly more enjoyable since stretch Break was installed. (The rating scores of data entry operators were 7 points higher on the analog scale for both these statements.)
Computer operators who used this software program with it's frequent short stretching breaks reported that it was definitely effective in reducing stiffness and muscle ache associated with long hours at the keyboard. They also credited the program with lowering their stress level. Another benefit was a heightened awareness of ergonomic issues, such as the need to take frequent mini-breaks and to set up one's workstation correctly. Users reported that the program increased their productivity and enjoyment with working at their PC, but these improvements were modest.
When respondents with data entry as their primary task were separated out from the others, it was discovered that data entry operators rated the effectiveness of the program considerably higher in all dimensions. This was especially true for crediting Stretch Break with increasing productivity and enjoyment of using their PC.
Last Updated: 09/20/98