Carpal tunnel is a term that strikes fear into everyone that uses a computer, and we all know how much computers are used in laboratories and research in general. Everything from data entry to notation and protocol documentation to grant, article, and proposal writing is digital today. But repetitive motion and associated musculoskeltal disorders (MSD) are not limited to computer users.1 In this article, we will discuss the technical aspects of repetition/duration and force as it applies to ergonomic risk in lab and office settings. And we will offer solutions to get you through the days and weeks pain-free.
Breaks and rest combat repetitive motion
The definition of repetition is doing things over and over again. In repetitive work, the same motions are performed using the same parts of the body in the same way, time and time again. In activities such as typing, mousing, or entering data by referencing paper source documents, the affected muscles, tendons, and joints can be used thousands of times a day, week after week, year after year. The risk of injury is even greater when repetitious jobs involve awkward posture (e.g. bent or flexed wrists) or forceful exertions such as repetitive overreaching for the mouse (which can lead to shoulder and neck pain).
Our goal from an ergonomic standpoint is to, first and foremost, strive for neutral and balanced actions. Additionally, reducing the number of repetitions experienced by each set of muscles, tendons, and joints throughout the workday and allowing time for recovery is paramount. The body has great capacity to repair itself. Problems arise, however, when the amount of damage or stress accumulated over the course of time overtakes the body’s ability to repair. This is when we experience pain. If the cumulative damage continues without allowing time to recover and heal, there is the potential for serious injury.
In order to introduce healing time, short breaks in repetitive tasks bring significant benefit. Break up data entry with variations in activity such as filing, reading, using the copier, or any other task that uses different muscles and motions than computer use. It is also good to include micro-breaks of just a minute or two every half hour or so during long data entry periods. Research has shown it is often better to take many small breaks than one long work break during the day. Try using software that tracks keystrokes and mouse movement and alerts you when breaks are appropriate.
Break down and analyze tasks
It is critical to examine and analyze the work being performed. Examine the job on a task-by-task basis. In many cases we have seen unnecessary repetitive work performed due to poor process design or evolution over time. When evaluating, ask yourself “can parts of this process be automated? Can equipment be linked directly for data collection? Can steps be eliminated or modified to improve flow or actions?” Investigate use of barcodes and readers to reduce data entry or entry readable/scanable forms or other types of information collection. It is always worth investing time to engineer a solution that will save significant time and effort in the long run.
An example: mouse use
Pain is often reported from mousing and usually attributed to over-use, and is often combined with poor mouse location. The conventional mouse requires a great amount of work to be directed through one arm, shoulder, and hand. It is a good idea to try to distribute this work and share it between both sides. One approach is the use of keyboard commands. Most operating systems contain keyboard commands or shortcuts for common tasks. Taking the time to explore and use these can greatly reduce mouse use, and once you get familiar with them will actually speed up your work.
Another remedy is to try one of the many “alternative” or “ergonomic” mice now offered. Some allow one to use both hands for mousing, sharing work between hands. Software programs allow you to automate common tasks (e.g. autofill) and develop scripts called macros to perform, reduce, or eliminate many actions. Their use can significantly decrease the amount of typing you need to do.
Force is the amount of muscular effort needed to perform work. Fatigue and injury track with the amount of force exerted. The more force required, the higher the risk of both.
Exertion force depends on many factors, including:
- The effort used to strike an object (e.g. key depression when typing)
- The shape and dimensions of an object you are working with
- How you grip an object or tool
- The precision of motion required to perform the task
- Duration of force applied by the muscles (e.g., the amount of time spent without a muscle-relaxation break)
- Awkward postures (bending, twisting, over-reaching)
Goal number one is to always have a neutral and balanced posture. Goal two is to reduce the number of repetitions or duration of exertion experienced by each set of muscles, tendons, and joints throughout the workday. Number three is to reduce the force applied to perform the task. OSHA provides excellent help through their eTool on ergonomics.2 Strive to recognize and reduce all the risk factors both on and off the job to effectively reduce the potential for repetitive motion pain and injury.
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