According to the Bureau of Labor Statistics, there are more than 60,000 foot injuries per year that result in lost work days. What’s more, of those foot injuries, 75 percent occurred when workers were not in compliance with safety requirements.
According to the National Council on Compensation Insurance, the average cost of a lost work day from a foot injury is $9,600. Eighty percent of all footwear injuries are caused by an object weighing no more than 30 pounds impacting the foot. The foot injury can cause temporary to permanent immobility for the worker, depending on the severity of the injury. As the workers have to move around the workplace the possibility for foot injury increases. Appropriate risk assessment for the workplace foot injury, selection of effective footwear, proper supervision, and enforcing the wearing of adequate worker foot protection would mitigate the impacts of foot injuries on workers and companies.
Foot anatomy and injury
The human foot is a mechanical structure composed of bones, joints, muscles, tendons and ligaments. The primary joints in the foot are the ankle, subtalar joint and joint between toes. The foot can be subdivided into the hind foot, the mid foot, and the forefoot. The hindfoot is composed of ankle bone and heel bone. The irregular bones of the mid foot, the cuboid, navicular, and three cuneiform bones form the arches of the foot, which serves as a shock absorber. The mid foot is connected to the hind- and fore-foot by muscles and the plantar fascia. The forefoot is composed of five toes and the corresponding five proximal long bones forming the metatarsus. Similar to the fingers of the hand, the bones of the toes are called phalanges and the big toe has two phalanges while the other four toes have three phalanges each. The joints between the phalanges are called interphalangeal; those between the metatarsus and phalanges are called metatarsophalangeal (MTP).
The most common types of foot injuries observed in the workplace are broken bones, puncture wounds, amputation, sprains, burns, lacerations, hypothermia and electrical shocks.
In general, the following are some of the workplace or work related factors that have the potential to cause foot injuries:
- Falling of heavy objects can crush a worker’s foot, e.g. falling iron bars can result in a broken bone
- If the worker is handling chemical solutions without wearing appropriate chemical footwear, in case of chemical spillages, burns on feet can occur
- High voltage electrical currents can cause electrical shock or fatal electrical exposure in wet environments
- If the workers are in extreme cold temperatures like refrigeration units or chilling plants without proper PPE, it may lead to hypothermia, frostbite and amputation of feet or toes
- Slippery surfaces like walking over sodium hydroxide spillage solutions in soap oil plant, water spilled, and smooth surfaces can cause a worker to twist, sprain, or fracture his or her foot
- Projected sharp objects in the workplace, e.g. projected iron nails on the scaffold working platform can cause lacerations on the foot. Broken glass, any sharp objects or loose nails on the floor can puncture the bottom of the foot
- Standing for extended periods can result in cumulative foot injuries
The other common causes for foot injuries are as follows: feet trapped between objects or caught in cracks, heavy objects falling on the feet while stacking, moving vehicles – especially when reversing without a banksman – workers using conveyor belts may end up with crushed or broken feet, even requiring amputations of the toes or feet. The presence of sharp metals in engineering or fabrication workshops can result in punctures to the sole of the foot. Working near unguarded machinery such as chainsaws and strimmers may lead to cuts or lacerations. In addition to this, molten metal splashes, contact with fire, and flammable or explosive atmospheres result in severe burns. Contact with sources of electricity including damaged live electric cables may result in electric burns. Incorrect footwear and poor lighting in the workplace can also lead to twisted ankles and fractured or broken bones because of slips, trips and falls.
“incorrect footwear and poor lighting in the workplace can lead to broken bones because of slips, trips and falls”
The environment’s hazards
As an active monitoring control measure, risk assessment should be carried out in the workplace so as to identify the preexisting foot risks that have a high probability of causing injuries. As part of the standard routine, foot risk hazards must be identified.
While conducting this hazard identification, any of the following techniques can be adopted, including: visual observation and task analysis. Visual observation means inspection throughout the workplace, at which point footwear hazards can be found out. The foot hazards vary by many factors, including the activity that has been carried out, the type of industry and its functions, the competency of the worker, and the work environment where the activity takes place.
In the construction industry, the risk of foot oriented hazards is higher than in other industries. I’m sure you can picture the scene: sharp objects such as nails protrude from platforms or walkways, tools are strewn around the working and pedestrian areas of the site, and the presence of paints and solvents liable to spill makes for potential slip risks.
The task analysis method can also be used while assessing footwear risks. As an example, if the worker is lifting and moving the load while carrying out hazard identification, the nature of the load, the work environment in which lifting takes place, and the type of footwear present can be assessed. Mainly, if the lifting activity is happening on the slippery surface or hard rough surface, or in a chemical usage area, the footwear type and quality must be evaluated properly.
Another way of carrying out hazard identification is by following manufacturers’ recommendations. It is a common practice that workers at a company – who are exposed to the same environmental and task hazards – will all wear the same footwear. The environment and tasks are crucial here, as footwear manufacturers must clearly recommend under which conditions particular footwear is to be worn. The worker involved in high electrical works, for example, cannot wear the same footwear as the worker who is working with hot work as well as with chemicals.
At risk workers
After identifying the hazards lurking in the environment, the next step is to identify which workers in those scenes are at risk of injury. In the Middle East, road workers are exposed to sunlight and its heat, so for them breathable footwear is a must. Conversely, those working at height like roofers, painters, and scaffolders need to wear highly gripped shoes. For workers exposed to chemicals, such as those in chemical warehouses and sulphur pits, chemical resistant safety shoes are obviously a must. Injuries from electricity would have a severe impact, especially if the workers were to walk over uninsulated or damaged cables. Whichever industry you are in, after carrying out the risk assessment, appropriate control measures must be suggested.
Safety shoe components
The insole is the non-removable component used to form the base of the shoe to which the upper is usually attached. The bottommost part of a shoe that comes in direct contact with the ground is called the outsole. The removable or non-removable footwear component used to cover part or the entire insole is the insock. The midsole lies between the foot bed and the outside and provides shock absorption and support for the wearer. The lining is the material which is use to cover the inner surface. Cleats protrude from the outer surface of the sole and the outsole is the one that cannot be bent at an angle of 45 degree under a load of 30 Newton.
Penetration-resistant inserts are the component placed in the sole to provide protection against mechanical penetration. The safety toecap is the built-in footwear component designed to protect the toes of the wearer from impacts of an energy level of at least 200 Joules and compression at a load of at least 15 kilo Newton. Safety toecaps are protective reinforcement caps under the upper in the toe area, which protect the foot from falling objects and compression. The material traditionally used for toecaps is steel, but in more recent years many safety boots instead have a composite toecap. Safety boots with steel toecaps contain a piece of steel in the toe area to protect the toes from several different hazards in the workplace. They offer more flat protection than composite toecaps and can essentially handle heavier weights above the basic safety requirement when compared with composite toe caps. Composite toecaps, on the other hand, are usually lighter than steel boots and are completely metal free and therefore do not conduct electricity as they are made up of carbon fibre or fibreglass.
The shank is a supportive structure that sits between the shoe’s insole and outsole and runs underneath the arch of the foot. It is the support structure that provides rigidity and stability in safety boots. The rear 10 percent of the total length of the footwear is called the seat region counter area. The upper refers to the part or parts of the shoe that covers the toes, the top of the foot, the sides of the foot and the back of the heel. The footbed, more commonly known as the insole, is the inside part of the shoe that runs under the bottom on the foot. The footbed of a safety shoe improves comfort for the wearer, which in turn helps to increases employee satisfaction and performance.
Selection of footwear
All risks associated with the job should be assessed to determine the specific requirements of the footwear. Workshop, maintenance and people working in mechanical laboratories or on geological, agricultural or engineering field trips should wear suitable boots with steel caps. All people working in laboratories should wear enclosed footwear. People working in chemical laboratories should wear enclosed footwear that is resistant to spills of hazardous substances. People standing or walking for long periods should wear supportive, enclosed footwear.
Fitting of footwear
The general points to be considered while selecting footwear are as follows:
- Inner side of the shoe must be straight from the heel to the end of the big toe and the shoe must grip the heel firmly
- Forepart must allow the toes freedom of movement
- Shoes must have fastenings to prevent the foot from slipping when walking
- Appropriate measurements must be done to ensure proper fit
- Consider using shock-absorbing insoles where the job requires walking or standing on hard floors
- Tight or wrinkled socks may cause discomfort so appropriate sock size should be selected
Protective footwear can have specific protective properties. Such elements include internal elements called toecaps, protecting the toes against impact and compression. The materials include steel, aluminium and certain plastics. Metal toecaps should be resistant to corrosion and plastic ones should maintain the required resistance to impact after chemical and heat exposures. Toecaps rear edges should be covered with foam to reduce foot compressions. The inserts should have appropriate dimensions and should be resistant to repeated bending. Metallic inserts should be resistant to corrosion and non-metallic ones to chemical and thermal ageing. Metatarsal protection safeguards the upper part of the metatarsus (the middle part of the foot) against crushing or contusions due to objects falling down, or cuts inflicted by sharp edges. The construction should ensure uniform distribution of the force generated during potential impact over the sole, toes and as large an area of the foot as possible.
Foot pain is common among workers that stand for long periods of time, including factory assembly line workers and brick layers. This can be controlled by following the administrative control measures. Good job design includes varied tasks requiring changes in body position and using different muscles. Job rotation, job enlargement and teamwork are all ways to make work easier on the feet. Job rotation moves workers from one job to another. It distributes standing among a group of workers and shortens the time each individual spends on their feet. Job enlargement includes more and different tasks in a worker’s duties. If it increases the variety of body positions and motions, the worker has less chance of developing foot problems. Teamwork allows workers to alternate between tasks which, in turn reduces the risk of overloading the feet. Rest breaks help to alleviate foot problems where redesigning jobs is impractical. Frequent short breaks are preferable to fewer long breaks. Redesigning the job alone will not effectively reduce foot problems if it is not combined with the proper design of the workplace. For standing jobs, an adjustable work surface can be provided. If the work surface is not adjustable, two solutions include: installing a platform to raise the shorter worker, or a pedestal to raise the object for a taller worker.
“foot injury rates are increasing and the statistics clearly emphasise that 75 percent of foot injuries are due to workers’ non-compliance with safety procedures”
Signage and flooring
By providing designated walkways, separating mobile equipment from pedestrian traffic, and by installing safety mirrors and warning signs, the incidents related to foot injuries can be decreased. In addition, proper housekeeping reduces the incident rate in the workplace. Using colour contrast like reflective strips and angular lighting to improve depth of vision in more hazardous areas such as stairs, ramps and passageways reduces the hazard of tripping and falling. Keeping safety signs in risky places where safety footwear is required when there are potential hazards is a common practice. Walking on a hard surface can cause a lot of discomfort and so anti-fatigue matting can also be useful wherever workers have to stand or walk as they provide cushioning which reduces tiredness through the feet and body. In addition, special anti-slip flooring or matting can reduce slipping incidents. If installed properly, these mats are useful, but workers may find that their feet burn and feel sore. The non-slip properties of the flooring mat cause their shoes to grab suddenly on the flooring making their feet slide forward inside the shoes. Friction inside the shoes produces heat that creates soreness and, eventually, calluses. A non-slip resilient insole can reduce this discomfort.
Foot injury rates are increasing. The statistics clearly emphasise that 75 percent of foot injuries are due to workers’ non-compliance with safety procedures. Proper housekeeping would reduce many foot injuries related to slips and trips. By wearing safety shoes appropriate to the hazardous nature of the environment, many foot injuries can be avoided. In addition, regular supervision and enforcing the workers to wear safety shoes would greatly reduce the number of injuries.