Ergonomics, the science and study of work, can teach us how to apply this information to optimize human well-being and overall work system performance.
Ergonomics is about more than good posture and nifty gadgets. It is the science and study of work, and the practice of applying data and theory to optimize human well-being and overall work system performance. The aim of ergonomics is to study and improve the “fit” between people, their jobs and their environments in order to improve performance, wellness, safety and health. Ergonomics includes physical, mental (cognitive and emotional), and organizational factors, as well as the way these factors interact within the work system. Ergonomics is as important for those in the veterinary field as in other areas of work — perhaps even more important, in some cases.
Musculoskeletal discomfort in veterinarians – the pain of practice
Musculoskeletal discomfort (MSD) and injury are common problems for those in veterinary practice. Over a five-year period, 27% of the cost of AVMA-PLIT veterinary worker compensation claims were due to “ergonomic injuries”.1 Depending on the studies, between 80% and 99% of veterinarians have experienced MSD in the past year, most commonly in the lower back, neck and shoulders. 2,3
While physical strain is an obvious culprit, it is important to remember that pain is not entirely due to biomechanical factors. It may be influenced by psychosocial factors, such as workload and lack of social or managerial support, and individual influences such as life stress, coping skills, and beliefs about and fear of pain. Low job satisfaction and high work stress are important risk factors for MSD in veterinarians. Long days and lack of breaks have been associated with this stress, and MSD has also been statistically correlated with a range of additional psychosocial factors, including stress associated with career structure, time pressures, client attitudes, lack of recognition by the public or by colleagues, lack of understanding from family or partners, and insufficient holidays.2
Physical ergonomics in veterinary medicine
Physical ergonomic risk factors in veterinary medicine include repetitive movements, forceful exertion, lifting, awkward postures, prolonged static loads, vibration or a combination of these. Some of the procedures associated with pain in veterinarians include rectal palpation, dentistry (equine and small animal), surgery, ultrasound examinations, and large animal obstetrics.2
While some hazards are inevitable in any work situation, there are ways to reduce physical risk by approaching the hazard via a risk control hierarchy (Figure 1). Not all problems will be amenable to all these controls; for example, you can’t completely eliminate the risk of injury from animals in an animal care setting. But the higher up the hierarchy you can work (eliminating the hazard or substituting a less hazardous alternative), the better protected you and your staff will be. Relying on the bottom two controls (rules and protective gear) will not give you a robust safety environment. Different ergonomic hazards may generate different solutions from different places on the hierarchy. In many cases, the staff involved with the task in question will be the ones who can devise the most usable solutions to the problem. This type of participatory ergonomics is capable of producing creative solutions as well as offering employees a sense of engagement in the process.4 Ultimately, this sense of engagement can be key to the staff adopting and using new equipment, protocols and procedures. Finally, thinking about ergonomics doesn’t have to be expensive; many solutions are already available, or may require changes in scheduling and flow rather than the purchase of expensive equipment. Furthermore, solutions that are safer for veterinarians and staff can also be less stressful for people and patients alike (e.g., calm, safe animal handling).
Specific veterinary activities: hazards and solutions
Veterinary practice varies a lot, so it’s not possible to describe the ergonomic hazards of every type of veterinary work. However, here are a few examples of how to minimize risks in certain practice areas.
1. Equine practice can be dangerous: during a 30-year career, equine practitioners can expect seven to eight work-related injuries severe enough to impede practice.5 Equine veterinarians describe dental procedures, obstetrical procedures, and the diagnosis and treatment of lameness as causing the most strain.6
Lameness exams, as well as other procedures performed on the distal limbs of horses, may require extreme postures, the application of force, and repetitive movements, and are thus overall the most ergonomically risky tasks performed by equine veterinarians. Wrist postures travel through extremes of flexion, extension and ulnar deviation during lameness exams. The risks involved in doing distal limb procedures are difficult to eliminate, but can be mitigated by postural awareness, adequate training for support staff, expertise and experience in the practitioner, practice organization (such as rotating duties among vets in the practice), educating horse and owner, and refusing to handle dangerous animals.
2. Equine dentistry is also considered by veterinarians to be very demanding for the arms, shoulders, back and neck. Motorized floats, adjustable equine head support, the use of trained staff to assist, and sedation of the horse may all help mitigate these demands. In multi-veterinarian practices, dividing the work equally among doctors may help reduce the risks from repetitive movements.
3. Small animal surgery has been associated with MSD in multiple studies. In fact, small animal veterinarians perceive surgery as second only to lifting when it comes to the development of MSD.7 A study of spay/neuter vets reported a 99% one-month period prevalence of MSD, with greater discomfort in those surgeons who spend more hours in surgery each week, and in those who work in spay/neuter for a greater number of years.3 Surgeons may reduce their fatigue and discomfort by sitting for surgery, or alternating between sitting and standing. For those who stand, the table should be adjusted to a comfortable height for each surgery. When working on deep-bodied patients, using a saddle chair or sit/stand stool may allow the surgeon to sit close to the table without interference between the table and the his/her knees.
Being able to change position during an operation, or between successive short operations, is associated with decreased fatigue and reduced pain after surgery. “Micropauses” of 15 to 30 seconds taken multiple times per hour reduce discomfort and fatigue and increase accuracy, especially if combined with active stretching or exercises that release the neck and shoulder tension inherent in surgical posture.
The use of efficient and gentle surgical techniques and appropriately maintained instruments can help minimize the forces required during surgery, thus mitigating the risk of high repetition. Further, it is possible to change grasp or technique to avoid awkward or tiring hand positions — e.g. changing between palm and tripod grasp when holding needle holders, or performing closures without the use of thumb forceps in order to avoid the pinch grip used with these devices.
Using a risk control hierarchy
As an example of using a risk control hierarchy, let’s look at a common task in veterinary practice — the lifting and carrying of animals or supplies. The first step is to identify whether there is even a problem with the lifting in your practice by knowing safe lifting limits. However, how much it is safe to lift depends on:
- Weight of load
- How many times a day do you lift the load?
- Distance of your hands from your lower back (closer = better)
- Height of lift (from floor or from above knee height? How high do you need to lift?)
- Twisting and side bending
- Working in a restricted space
- Good grip versus an irregular, bulky, floppy, unpredictable load
- Flooring condition (dry, clean, good condition, or wet or uneven)
- Communication and coordination when lifting as a team.
While many of these factors may seem hard to modify, there are some ways to mitigate them:
- Weight of load (patients): You can’t change the size of an individual patient, but you could restrict your patient population (for example, become a feline practitioner), if that fits with your mission and community needs.
- Weight of load (other stuff): Break down large supply packages into manageable armloads. Use two people to lift large heavy objects. Use equipment (rolling cart, dolly) to help lift and move large heavy objects.
- Distance of your hands from your lower back: The further the object from your center of gravity, the less weight you can lift and carry (or the more strain you will feel from a given lift), so carry as close to your body as you can. A wide stance while lifting from the floor can help you bring the weight as close as possible to the center of your body.
- Height of lift (patients): Can you lift the standing dog, rather than the down, anesthetized dog? Can you lower the table you’re lifting him onto?
- Height of lift (other stuff): Store only lightweight items on high shelves. Heavy items that need to be lifted and carried (i.e. cases of wet food or trays of instrument packs) should be near waist level.
- Avoiding twisting and side bending
- Working in a less restricted/obstructed space: Remove unnecessary obstructions from your workspace and storage space.
- Grip on load (patients): Turn a floppy unpredictable load with no handles into a firm balanced load with well-distributed handles (or even wheels!) by using a stretcher. Some clinics recover large dogs on a rolling stretcher so you don’t even have to move the dog from floor to stretcher. Use a rolling lift table to transport patients through the clinic.
In this example, progressing down the hierarchy from top to bottom, we were able to substitute the risk by limiting the patient population to smaller patients (or, you could say we eliminated the risk of lifting dogs). We used several engineering controls: stretchers, lift tables, carts and dollies; we eliminated obstacles in the way of the lift; and ensured suitable flooring conditions. These engineering controls go along with or require several administrative controls, such as rules about when staff must use lifting devices, about storage locations, and about clean dry floors.
General advice in ergonomics
Whether you are doing surgery, palpating cows, or entering data, consider the following:
- Beware of repetitive manual tasks. These tasks may require a combination of repetitive movements that can at times require force, or may be performed with awkward positioning of the hands and wrists. Such tasks can include surgery, dental work, drawing up and administering injections, using computers and tablets, and clipping and prepping patients for surgery. Alone, each of these factors (repetition, force, posture) is only moderately associated with pain in the hand and wrist, but when combined, their association with hand/wrist pain is strong.8 By reducing any one of these three factors, you can reduce the risk of hand and wrist pain. If repetition is required in the job, consider reducing force by using lighter tools or instruments, or find tools or techniques that allow for less awkward positioning.
- Avoid awkward or tiring positions. In the majority of cases, awkward postures with extreme flexion, extension, or ulnar or radial deviation are not necessary video or take photographs during the task in order to evaluate hand and body motions and postures, and to ensure that inefficient techniques are not leading to awkward positions. Many mobile phones have the capability of recording video, and may be mounted and secured in a nearby location to allow recording of the procedure. Alternatively, a second person may be able to record video while the veterinarian works. After viewing video and noting desired changes, veterinarians may be able to rely on self-monitoring to avoid prolonged static awkward positions.
- Be aware of common strains. Watch out for postures and manual strains that are common to multiple activities. The degree of neck flexion while using a laptop computer or mobile device is similar to that in surgery; too much time spent in one activity may compound the strain caused by the other. Similarly, using your thumbs on computer trackpads or for texting may exacerbate thumb pain from surgery. Fortunately, these secondary strains can often be reduced by changing our use of technology. A quick text or a short time on a laptop is fine, but for lengthier interactions with technology, consider an external mouse and keyboard to keep neck, wrist and thumb positions as neutral and strain-free as possible.
- Take micropauses. Studies on office workers9 and human surgeons10 have shown that “micropauses” of 20 seconds every 20 minutes can reduce discomfort and fatigue, and even increase accuracy. Take 20 seconds to stretch, stand up, shake out, move around. It doesn’t matter so much what specific movements you do, only that you take that time to release the muscles you are holding. The benefits may be related more to the neurological “reset” than the actual musculoskeletal results of the stretch.
- Train your body. To some extent, human bodies can adapt to musculoskeletal strains, given adequate time for rest, recover and adaptation. Ligaments will increase in strength, size and collagen content with use,11 so that veterinarians performing tasks they’re accustomed to may have greater resilience than the new recruit. Performing repeated unaccustomed movements with the hands can be a risk factor for hand and wrist disorders, so it may be valuable to begin new hires with a lighter repetitive task schedule, and then work up to a full schedule once their bodies have become conditioned to the work.
1 AVMA-PLIT, Preventing Back Injuries. Safety Bulletin, 2015. 23(2).
² Scuffham AM, et al. “Prevalence and risk factors associated with musculoskeletal discomfort in New Zealand veterinarians”. Applied ergonomics, 2010. 41(3): p. 444-53.
³ White S. “Prevalence and Risk Factors Associated with Musculoskeletal Discomfort in Spay and Neuter Veterinarians”. Animals, 2013. 3(1): p. 85-108.
⁴ Hignett S, Wilson JR, Morris W. “Finding ergonomic solutions–participatory approaches”. Occupational medicine, 2005. 55(3): p. 200-7.
⁵BEVA. “Survey reveals high risk of injury to equine vets”. Veterinary Record, 2014. 175(11): p. 263.
⁶ Loomans J, et al. “Occupational disability and job satisfaction in the equine veterinary profession: How sustainable is this ‘tough job’ in a changing world?” Equine Veterinary Education, 2008. 20(11): p. 597-607.
⁷ Scuffham AM, et al. “Tasks considered by veterinarians to cause them musculoskeletal discomfort, and suggested solutions”. New Zealand Veterinary Journal, 2010. 58(1): p. 37-44.
⁸ Bernard BP, ed. “Musculoskeletal disorders and workplace factors: a critical review of epidemiologic evidence for work-related disorders of the neck, upper extremities, and low back”. 1997, National Institute for Occupational Safety and Health, U. S. Department of Health and Human Services: Cincinnati, OH.
⁹ Barredo RDV, Mahon K. “The effects of exercise and rest breaks on musculoskeletal discomfort during computer tasks: an evidence-based perspective.” Journal of Physical Therapy Science, 2007. 19(2): p. 151.
10 Dorion D, Darveau S. “Do Micropauses Prevent Surgeon’s Fatigue and Loss of Accuracy Associated With Prolonged Surgery? An Experimental Prospective Study”. Annals of Surgery, 2013. 257(2): p. 256-259.
11 Solomonow M. “Ligaments: a source of musculoskeletal disorders”. Journal of bodywork and movement therapies, 2009. 13(2): p. 136-154