What is ergonomics, and what does it mean to the average construction worker on the job site? Ergonomics is the science of designing equipment to maximize productivity by reducing operator fatigue and discomfort while doing the job. This involves finding the best fit between the worker, the job and any equipment being used. Although considered new to construction, ergonomics has been around for quite a while. In 1894, the split-level scaffold was designed for masonry work in the United States. It was used to increase worker productivity by decreasing the time a worker spent doing a task in an awkward position. The need for such solutions is no less important in construction today.
According to the National Institute for Occupational Safety and Health (NIOSH), the number of back injuries is 50 percent higher for the construction industry than the average for all other U.S. industries. Seven out of 10 construction workers have reported some type of work-related musculoskeletal pain.
This class of injuries is referred to as work-related musculoskeletal disorders (WMSDs). These injuries include back pain, tendonitis, carpal tunnel syndrome, strains and sprains of all kinds. On a construction site, these injuries are the result of lifting, repetitive motions and working in areas of limited space. There is a mindset in construction that these types of injuries are the “nature of the beast” and can’t be avoided. Ergonomics seeks to change that. Individuals are at increased risk for WMSDs if they often perform the following tasks:
• Carry heavy loads
• Work on their knees
• Twist their hands or wrists
• Stretch to work overhead
• Use certain types of hand tools
• Use vibrating tools or equipment
This sounds like an average day at just about any construction job, but it doesn’t have to result in WMSDs. Many of these injuries can be prevented with small changes in tools, equipment or work practices. Ergonomic improvements are changes made to how a worker’s capabilities match the task performed’s demands.
Many WMSDs are caused by two categories of activity common in the construction industry: ground-level activities and overhead work. Each category has its own set of physical demands, parts of the body affected and solutions available.
Much of the work done on a construction site requires workers to be close to the ground or floor to perform the task at hand. Employees may spend a good part of their day installing flooring or electrical wiring. This causes the employee to bend, stoop, squat and kneel, all of which puts a great amount of strain on the knees and lower back. Over time, these strains increase the likelihood of a serious injury. This position also can make doing a job harder because the worker is not able to lift, push or pull effectively.
Although floor-level work cannot be removed from construction, there are ways to minimize the stress and strain on the back and knees. Often, the floor is used in place of a workbench at a job site because it is flat and solid. This increases the amount of time a worker spends stooping and bent. This can be alleviated by using a table or sawhorses that bring the work surface up to waist level. There also are tools that have extensions that allow the worker to stand upright while using the tool. An example would be an auto-feed screw gun with an extension. The use of kneeling creepers can help reduce the stress on a worker’s knees by allowing the worker to sit while working or to kneel on a cushioned pad.
Overhead work can lead to stresses and strains on the back when workers reach with one or both hands above the shoulders. The bones of the shoulder and ligaments used to attach the muscles are separated by a bursa, which helps to increase flexibility and decrease friction at the joint. The neck also is at risk when doing overhead work. It is technically part of the back, so it is at risk for the same injuries from misuse or overuse.
Again, it is impossible to remove this type of task from construction, but the risk of injury can be reduced by changes in work practices or equipment used. Something as simple as using a ladder, lift or hoist can reduce the angle of the arms overhead or reduce the amount of time needed to perform a task. It also is possible to use tools with extensions to decrease the need for the employee to stretch to reach the work to be done.
Many of these injuries can be avoided by thinking about the body’s position before getting down to the job at hand. Although setting up sawhorses or bringing in a lift may take a bit more time, it will keep your employees safer in the long run and help decrease injuries on your job sites.
KELLY is a safety and health specialist with Intec, a safety consulting, training and publishing firm that offers on-site assistance and produces manuals, training videos and software for contractors. She can be reached at 800.745.4818 or firstname.lastname@example.org. Joe O’Connor edited this article.