Construction Ergonomics: Major Risks and How to Control for Them
Construction work puts a lot of stress on the body, but with the right solutions you can reduce the risk of ergonomic injury on the construction site.
The U.S. Bureau of Labor Statistics states that ergonomic injuries account for 33% of all worker injury and illness cases in the workplace, with direct costs to the industry of over $20 billion dollars annually and estimated total costs of $45-54 billion annually.
Compared to the lost time of the average injury or illness (8 days), ergonomic injuries result in 38% more lost time days (11 days).
Given these staggering numbers, it is surprising how little attention ergonomics receives in most organizations.
Ergonomics is a science that focuses on designing spaces, workplaces, tasks, and processes to improve well-being and prevent strain and muscular injury.
In the context of construction, we can simplify the concept down to fitting the job to the employee rather than forcing the employee to fit to the job. That means avoiding unnecessary uses of force, reducing stress on the body, and eliminating tasks performed in awkward positions.
Proper ergonomic design and solutions can prevent and reduce the risk of musculoskeletal disorders (MSDs). While these disorders are generally short-term, they can develop into long-term, disabling conditions that will severely impact an employee's ability to perform their work and enjoy their life.
Major Ergonomic Risks
When a task isn't fit to an employee's capabilities and limitations, it can result in two types of ergonomic injury: cumulative trauma disorders (CTDs) and sprains or strains.
Cumulative Trauma Disorders
CTDs, or repetitive strain injuries, are soft tissue injuries caused by repeated exposure to an ergonomic stressor.
Many workplace tasks become risky when they are overdone. They can be performed safely for a limited amount of time and with adequate rest periods at regular intervals. However, when they are performed too often or for too long without allowing the body to recover, these tasks can result in a repetitive strain injury.
These injuries generally develop in smaller parts of the body, such as the fingers, wrists, elbows, or neck.
In the construction industry, the three most common types of CTD are tendon disorders, nerve disorders, and neuro-vascular disorders.
These injuries are caused by the inflammation of the tendon or the tendon sheathing due to repetitive rubbing against ligaments or bone.
The most commonly known tendon disorder is called Lateral Epicondylitis, but you probably know it as tennis elbow. In this condition, the outer part of the elbow becomes painful and tender. The pain from tennis elbow can extend to the back of the forearm and affect grip strength.
When nerves are compressed repeatedly against bones, ligaments, and tendons, it can make moving the affected part of the body extremely painful.
One of the most well-known nerve disorders is carpal tunnel syndrome. With carpal tunnel, the median nerve that travels through the wrist is compressed, resulting in pain, numbness, and a tingling sensation in the thumb, index finger, and wrist.
In time, carpal tunnel weakens grip strength, and OSHA estimates that the total cost of this injury amounts to $64,842 for the employer.
These disorders occur when the blood vessels or nerves are constantly compressed due to exposure to vibration or temperatures cold enough to reduce blood flow to the extremities.
This condition is commonly known as Raynaud's disease. In the construction industry, the fingers are most affected by this. When a worker is afflicted with it, the fingers turn white and then blue if the exposure continues for too long.
When the stressor is removed and the blood returns to the area, the fingers then turn red and the affected worker experiences a painful burning sensation.
(Learn more about the Risk Factors for Developing Musculoskeletal Disorders.)
Sprains and Strains
Unlike CTDs, sprains and strains are caused by a single, forceful event and develop instantly.
Sprains and strains occur when a worker performs an activity that surpasses their physical limitation, like suddenly lifting a heavy or awkward object.
(Learn more in Safe Lifting: Don't Put Your Back on the Line.)
Sprains and strains typically affect larger segments of the body, such as the back, legs, and shoulders. And the risk of injury increases with every additional ergonomic risk factor that is present, such as static loading, repetition, force, contact stress, awkward posture, and vibration.
While we tend to use the terms interchangeably, sprains and strains are actually different. Both are stretches or tears in body tissue, but sprains refer to injuries to the ligaments while strains refer to those that happen in a muscle or tendon.
Like CTDs, these injuries are costly. OSHA estimates that the total cost to the employer is $64,842 for a sprain and $69,213 for a strain.
Ergonomic Hazard Controls in Construction
Now that we know what kind of injuries we're dealing with and how costly they can be, we need to discuss solutions.
Every organization should assess the ergonomic hazards on its job sites, based on the scope of work, injury history, and the best business practices. This hazard assessment should be the foundation of the ergonomics program.
Moreover, it is important to note that there is no silver bullet for all ergonomic hazards. Employers must consider and implement multiple control methods, often in combination, to keep workers safe.
Here, I will list a few simple and cost-effective solutions that construction operations can implement to solve common ergonomic problems in their industry.
Stooping, Bending, and Kneeling
Construction work can involve a surprising amount of stooping, bending, kneeling, and squatting, often for extended periods of time. Workers who are tasked with fastening or connecting construction materials are especially likely to spend a lot of time in these awkward positions.
One great solution to this problem is to ensure workers are provided with tools that allow them to perform their work in an upright position.
Here are some examples of these:
- Auto-feed screw guns with an extension to assist workers in securing subflooring, false floors, and decking and roofing materials.
- Powder-actuated fastening tools with a stand-up handle allows employees to make steel-to-steel connections, fasten metal tracks to concrete, or install plywood on concrete without needing to constantly kneel and rise while doing the job.
- Manual or battery-operated rebar tying tools allow employees to tie rebar while standing and eliminate the need for the rapid and forceful hand motions used when performing the same task with pliers.
- Motorized screeds (or vibratory screeds) eliminate kneeling, reduce repetitive movement, and substantially reduce the force needed to level concrete.
- Kneeling creepers with cushioned knee support and chest support reduces stress on the knees and back when installing tiles or deck membranes - and does it without velcro or leather straps that can interfere with blood circulation.
- Split-level adjustable scaffolding keeps the bricks at waist level when doing masonry work, which reduces the need for stooping.
Overhead work creates substantial stress on the shoulders and arms. Working with your arms up is never comfortable - add repetitive motion, forceful grip on tools, and twisting the body and you've got significant potential for an MSD.
Some solutions include:
- Mechanical lifts reduce the need to reach overhead while holding and positioning objects. The lift will hold the object to be installed, leaving the worker's hands free to do the work under substantially less tension.
- Elevated work platforms provide a stable working surface that reduces the need for awkward postures while also eliminating the risks associated with ladders and scaffolding.
- Extension shafts for drills and screw guns allow workers to perform overhead installations while keeping their hands at waist level. The employee can push with their biceps instead of their shoulder, which is a less strenuous position.
- Extension poles for powder actuated tools avoids the exhausting work performed with hands above the head. The extension pole might also eliminate the need to work from a ladder, which is also strenuous.
- Spring-assisted drywall finishing tools reduce the force required to push the compound onto the wall by 75%.
- Pneumatic drywall finishing tools might not reduce the repetitive motion or eliminate all of the awkward positions involved in finishing drywall, but they do reduce the pressure required, thus decreasing the risk of ergonomic injuries.
Lifting and Handling Materials
Lifting and handling heavy and large materials puts a lot of pressure on the back, shoulders, and neck. Heavy objects can dig into a worker's hands and impede circulation. Holding them for extended periods of time can lead to conditions such as tendonitis or carpal tunnel syndrome.
Here are some options to decrease these risks:
- Reduce the weight of the materials being handled. This can be achieved by buying smaller cement bags, packaging materials in several smaller boxes instead of a large one, or using lightweight concrete masonry blocks (which are 30-40% lighter than regular concrete blocks).
- Provide mechanical, hydraulic, or vacuum lifts to handle window panes or drywall panels.
- Provide mechanical lifts or carts when handling large and heavy objects, such as barrels.
- Special handles for handling large drywall panels reduce the grip force required to hold them as well as the effects that the sharp edges have on blood circulation.
- Powered and non-powered carts reduce the need to transport heavy objects by hand, such as sheet materials or pipes.
- Using pre-blended mortar and grout mixes instead of making them on site eliminates the need for lifting heavy cement bags and mixing them by hand. Cement bags are around 100 pounds and your employees might need to handle hundreds of them each day on large jobs.
- Use skid plates to move concrete-filled hoses. Concrete-filled hoses are heavy and awkward to handle, so your employees have to make jerking movements to drag them and they often get caught in re-bars. A skid plate makes the hose slide on the re-bar, reducing the amount of force required to move them as well as the sudden movements required when the hoses get caught.
Hand Intensive Work
Employees in construction spend a lot of time gripping tools and materials, which places a lot of stress on the hand, wrist, and elbow. In time, this can lead to serious muscle or joint injury.
Thankfully, there are solutions that will reduce these risks:
- Easy hold gloves for mud pans are a great way to reduce the hand force required to hold a drywall mud pan. The glove attaches to the pan and holds it to the employe’s hand without needing a forceful grip. Considering that the pan often weights up to 5 pounds and the employee does the task all day long, this eliminates a significant amount of strain.
- Power caulking guns require a lot less force than the trigger on traditional caulking guns. Using them reduces the risk of carpal tunnel.
- Opt for low vibration power tools or provide workers with anti-vibration gloves. High vibration power tools can lead to reduced blood circulation, which is exacerbated by a forceful grip. This can lead to conditions such as “white finger” or “hand and arm vibration syndrome."
- Use power brushes instead of hand wire brushes when clearing rust or other materials. Power tools reduce the need for a forceful grip, as well as repetitive motions.
- Quick threading lock nuts can be positioned or slid on the rod to the desired location. This reduces the installation time and eliminates a lot of repetitive movements.
- Ergonomic tools can also help. While these are not always clearly defined or certified, here are some basic rules:
- Tools should conform to the geometry of the hand.
- Pistol grip and inline tools should have a handle about 5 inches long, and a handle diameter of 1 to 1.5 inches.
- Handles that end in the palm of the hand (too short) are not recommended.
- Pliers and crimping tools should have a handle length of 4 inches minimum and a recommended handle span of 2.5 inches.
Reduce the Risks
These are just a few suggestions to improve the ergonomics of your construction worksite. Construction companies should also make sure that employees receive adequate ergonomic training in order to identify and recognize the risks, as well as buy into the control measures.
Unfortunately, it is virtually impossible to eliminate every single forceful task or repetitive movement in construction. Having a well-crafted ergonomics program, however, is your best chance to reduce the likelihood and severity of work-related musculo-skeletal disorders.