Points of pain

Aug. 1, 1998
The study of occupational injuries, especially repetitive- motion injuries, includes examining the design of workplaces. Most workplace modifications are inexpensive, ranging from adjustable chairs or foot rests to workstations that have variable work surfaces. Such alterations significantly reduce workplace stress.

Certain workplace modifications help hygienists prevent occupational injuries.

Charron Contival

The study of occupational injuries, especially repetitive- motion injuries, includes examining the design of workplaces. Most workplace modifications are inexpensive, ranging from adjustable chairs or foot rests to workstations that have variable work surfaces. Such alterations significantly reduce workplace stress.

Alleviating workplace stress increases employee productivity and efficiency, as well as morale. There are also noticeable decreases in lost workdays, employee turnover, and workers` compensation claims resulting from repetitive-motion injuries.

What is a repetitive-motion injury? Generally, it`s defined as any injury to the musculoskeletal structure caused by repeated identical or similar motions performed during the routine course of a person`s job duties. The most common example is carpal tunnel syndrome, which is caused by the overextention or overuse of the wrist, resulting in inflammation of the median nerve. The median nerve runs through a channel in the wrist called the carpal tunnel. Inflammation or swelling of the median nerve causes such symptoms as tingling or numbness in the fingers or hands, pain, burning or itching in those same areas, and, in severe cases, atrophy of the thumb muscles and general weakness of the hand.

Essentially, any musculoskeletal injury that has resulted from repeated motions - particularly those performed at work using force, vibration, or impact - can be considered a repetitive-motion injury. For example, someone who spends all day in front of an improperly positioned computer terminal might develop a pinched nerve in the neck, weakness in the arms/shoulder/hands, back pain, or leg discomfort. All such symptoms can be evidence of a repetitive-motion injury or a developing problem that needs immediate attention.

Let`s examine some specific hazards encountered in dental offices and how to minimize risks of injury.

Poor patient positioning

This is a frequent concern expressed by RDHs in our workshops and seminars. Patients positioned too low or too high can cause the hygienist to either hunch over or stretch out, neither of which is conducive to comfortable performance of job duties.

Force yourself to mentally note your patient`s position. While height placement of the patient will vary depending on the height of the hygienist, some basic rules should be followed. The patient should be in a position when reclining that allows you to perform necessary procedures without causing you to stretch out or hunch over. Your forearms should be at an angle approximately 45 to 90 degrees from your upper arms, your back should be in an upright position with a slight foward angle, and your shoulders should be straight and relaxed.

In addition, review your equipment. Chairs should be fully adjustable. Typically, the gas-operated style works best, with height adjustments available at the touch of a lever. Chairs should have moveable armrests and a footrest or rail running around the entire base of the chair. Castors should roll freely and without obstruction.

Back soreness at day`s end

This is another big concern. The cause can be rooted in several areas. Proper patient positioning can help immensely, but also you need to consider a couple of other choices. Back support belts are not a popular option, largely due to esthetics and being uncomfortable to wear, but they can help.

A recent study states that back support belts can reduce back injuries by as much as 30 percent. There are two types of back support belts: a rigid style and a softer, elastic style. According to the study, the rigid style increases intra-abdominal pressure, which, in turn, provides more support of the stomach, back muscles and vertebrae. There also is a theory that the rigid style makes it more difficult for the wearer to turn or lift improperly, reducing the risk of twisting back injuries.

Another side to preventing back soreness is exercise. That`s not a solution many of us want to hear, but it remains true. The more physically fit you are, the less tired and sore you`ll be at the end of the day. If your muscles are toned and strong, you`ll experience less fatigue and tiredness, and have a much lower risk of a back injury. A doctor, physical therapist or physical trainer can give you a specific list of exercises that, done regularly, will strengthen your back muscles.

Taking frequent breaks can alleviate back soreness. It`s not always possible to take a break during a long procedure, but you can take breaks between job duties or before your next patient arrives. A quick walk, stretching, or flexing - or even quietly sitting in a supportive chair - can be restful and rejuvenating.

Handpiece vibration

Most manufacturers of handpieces try to minimize the amount of vibration, but occasionally we see complaints in this area, usually about older equipment. While replacement of capital equipment is usually the doctor`s decision, this solution should be considered in the interest of the employee`s comfort and safety. A workers` compensation claim for carpal tunnel syndrome actually can cost more than replacing older or defective equipment.

Wrist braces or protectors also can be considered. However, they are not entirely practical. First, the wrist protector typically is designed to provide a brace, or support, from the forearm to the palm of the hand, preventing the wrist from bending or flexing inappropriately. While this helps lower the risk of inflammation in the wrist area, it also makes it virtually impossible to use normal hand position during hygiene procedures. Gloving over the wrist protector during procedures that include aerosolization of blood or saliva is an even more important concern.

Again, frequent breaks and exercises - bending, flexing and rotating the wrists and fingers - are called for. The idea is to relieve stresses and pressures by forcing the hands and wrists into moving in ways other than how you normally use them.

Computer work

There are several important things to remember in this area to avoid the risk of repetitive-motion injuries. Three-quarters of the monitor screen should be positioned at eye level or below and approximately 36 to 40 inches away from the face. This can be accomplished by using adjustable monitor arms or shelves, counter or workstation arrangements or other engineering means.

The keyboard should be on a keyboard shelf or workstation surface that allows for comfort and placement of hands and forearms at a 90-degree angle from the body. There should be room in front of the keyboard for a wrist pad or rest that offers support and relief.

The chair used for data entry also is an important component of ergonomic issues. Chairs should be fully adjustable for proper seat height and back, or lumbar, support. Whether or not the chairs should have armrests is largely determined by where the chair is being used. Sometimes armrests actually impede access to the keyboard, thus increasing the chance of injury. If the environment is appropriate, height-adjustable armrests can be useful in reducing fatigue.

Even with a fully adjustable, ergonomically designed chair, an extended period of time spent in front of a computer screen can result in leg or back pain. An adjustable footrest placed under a workstation offers a simple, effective solution.

Take some time to evaluate the amount of time during any given day that you spend doing tasks or duties that include any of the exposures we?ve discussed here. If you feel you?re at risk in developing a repetitive-motion injury, or perhaps already have some of the symptoms, discuss the situation with your employer. As we?ve pointed out, the cost of a workers? comp claim can be higher than making modifications to the work environment.

Treatments for repetitive-motion injuries range from simple solutions, such as wrist protectors, to more complicated resolutions, such as surgery or even job retraining in another field. Obviously, it?s in everyone?s best interests to avoid injuries in the workplace. A little assessment and advance planning may be all that is needed to avoid them.

Charron Contival is a free-lance writer, photographer, and business consultant based in Hollister, Calif. As the owner of a consulting firm that assists clients with OSHA-related issues, she has provided in-depth training on a variety of technical, regulatory, and procedural topics. She can be contacted at (408) 637-5599.