Plantar fasciitis is a painful condition of the sole of the foot. It is an inflammation of the plantar fascia, a tough thin band of connective tissue that stretches from heel to toe. Plantar fasciitis is the most common foot problem in the United States and can be caused by a variety of factors.
Workers who are on their feet for most of the day are at risk for plantar fasciitis. Continuous weight on the feet can strain the plantar fascia and eventually damage it, resulting in inflammation. The type of floor in the workplace plays a part in the development of plantar fasciitis and related problems. Hard surfaces, such as concrete floors, are notorious for complaints of foot and leg pain. Floors made of more resilient material, such as wood or carpeting, are easier on the feet and can reduce the risk of foot pain.
Workers who stand in one spot for a long time, such as machine operators, need floor mats at their workstations. The primary function of floor mats is to cushion the feet and legs against the strain of continuous standing. Many types of commercial floor mats are available to meet the demands of any manufacturing environment: weather resistant, oil resistant, beveled edges, different materials, various thicknesses, different prices.
Be careful not to select mats that are too thick. The excess thickness can be a trip hazard if it entraps workers’ feet, just as walking on thick foam is awkward and difficult. Mats in high traffic areas will wear out sooner and need to be replaced more quickly than those in low traffic areas. Make sure the floor mats are placed out of the way of forklifts and other vehicles-these can tear up the mats in a hurry if they run over them.
In addition to floor mats, workers who are on their feet a lot need good shoes. The shoes should have firm soles that are engineered to absorb the forces generated by standing and walking. Shoes that are run down at the heels need to be replaced. Even if the rest of the shoe looks fine, the soles are worn out and no longer cushion the feet adequately.
Shoe inserts can provide additional cushioning, above and beyond the protection from good shoes. Inserts can also provide arch support, a boon for those on their feet all day. Take care to select inserts that fit both the contours of the feet and the inside of the shoe. Inserts should not rub or chafe, nor cause blisters or calluses. Over-the-counter shoe inserts can be effective for some workers, while others may require custom-made orthotic shoes or orthotic inserts.
Because heavier people put more weight on their feet, a high body mass index is also a risk factor for plantar fasciitis. Losing excess weight will reduce the forces on the soles of the feet and lessen the risk of foot problems.
Plantar fasciitis is not the bane solely of those who are on their feet all day. It can afflict desk jockeys who sit much more than they stand or walk. Runners and joggers can also suffer from plantar fasciitis. The repetitive forces from running can cause microtears in the fascia. These microtears accumulate over time, which can lead to inflammation of that fascia and result in plantar fasciitis.
Another contributing factor for plantar fasciitis is related to aging. You may not realize this, but you have fat feet. Literally. There are pads of fat on the bottom of your feet that provide internal cushioning. This fat layer spreads the body weight more evenly across the soles so the weight is not concentrated in one spot.
Unfortunately, this fat layer becomes thinner as we get older. With less fat to cushion the soles of our feet, the pressure can increase to the point that it causes foot problems. Personally, I’ve always felt that this fat loss was highly unfair: as we get older, the beneficial fat on our feet becomes thinner while the fat that isn’t beneficial (on hips and belly) becomes thicker. Mother Nature can be contrary at times.
To compensate for this loss of fat from the bottom of our feet, we need more external cushioning as we get older. This can be in the form of thick-soled shoes, floor mats, or shoe inserts, all of which must be replaced promptly when they wear down.
Because of the inflamed condition of the plantar fascia, putting even a little weight on the foot can cause excruciating pain, especially in the morning when taking the first steps out of bed. This is a good sign that all is not well with your sole.
The good news is that plantar fasciitis, as painful as it is, is usually not disabling and can be treated successfully. Stretching the calf muscles before getting out of bed can reduce the pain of the first step. This involves pushing the heel down while pointing the toes upward towards the body (the opposite of “pointing your toes”). Night splints, which keep the ankle at approximately 90 degrees, can also help reduce that first-step pain. The newer sock-like splints are much more comfortable than the hard plastic splints that were first used.
Other treatments for plantar fasciitis include physical therapy, massage, heat treatment, and anti-inflammatory drugs. Icing the bottom of the feet can reduce inflammation and pain. For cases that do not respond to these conservative treatments, surgery may be needed.
As with all types of ergonomic injuries, prevention is the best option. If you can choose the floor material, use resilient flooring (wood or carpet) in places where workers will be on their feet a lot. Provide floor mats in areas of prolonged standing and keep them in good repair, replacing the mats when they wear out. Shoes with specially engineered soles to absorb walking forces (such as athletic shoes) can also protect workers’ feet. Inserts and/or orthotics are other options.
Such simple preventative measures can go a long way in saving one’s sole.
Delia Treaster, Ph.D., is a certified professional ergonomist and writes on various ergonomic issues, drawing on decades of experience in occupational ergonomics. She has been an ergonomic contractor with Humantech, one of the largest workplace ergonomics consulting firms in the United States. Prior to working for Humantech, Delia was an ergonomic consultant for the U.S. Postal Service, a senior ergonomic specialist with Travelers Insurance, and a research scientist at Battelle Memorial Institute. She has a master’s degree in human factors engineering and a Ph.D. in biomechanics from Ohio State University.
E-mails to Delia can be sent firstname.lastname@example.org.
Editor’s note: “Ergo Corner” is part of a series of guest spots by industry experts that will appear regularly on ASSEMBLY’s blog page. Check back frequently to read more commentaries from Delia, as well as contributions on product testing, automated assembly systems, electronics assembly and robotics.