NIOSH offers solutions for sonographers | 2007-03-01…

NIOSH offers solutions for sonographers

Adjustable workspace reduces injury

Sonographers at St. Peter's University Hospital in Piscataway, NJ, were reaching as far as 24 inches, pressing with a force of 4 to 8.5 pounds to perform imaging on pregnant women. Some of their shoulder abduction angles were as high as 70 or 80 degrees. Not surprisingly, they suffered neck, shoulder, and arm pain.

"We noticed that many of the classical biomechanical stress factors associated with heavy industry jobs were part of what they do," says Daniel Habes, MSE, CPE, an industrial engineer with the Hazard Evaluations and Technical Assistance Branch of the National Institute for Occupational Safety and Health (NIOSH) in Cincinnati.

The health hazard evaluation, conducted in 1999, led to specific recommendations to reduce those stresses. Now all hospitals can follow some basic parameters offered in a new NIOSH document on "workplace solutions" for reducing musculoskeletal disorders among sonographers. (See below.)

Preventing work-related MSDs in sonography

NIOSH recommends the following controls to reduce the risk of musculoskeletal injury for sonographers:

Equipment

Provide adequate workspace for personnel, sonography equipment, the patient table, and other equipment.
Ensure that sonography equipment is fitted with a high-resolution screen that has a high refresh rate (85 Hz or higher), a noninterlaced monitor, and an easily adjustable "brightness control" to reduce eye strain. Position the equipment monitor directly in front of the sonographer.
Position the keyboard to allow the arm to be in a relaxed position, with the upper arm close to the body (minimal flexion and abduction), and the elbow at a 90-degree angle. A laptop computer may enable the sonographer to achieve a favorable position with respect to the patient. However, be aware that laptops can present other problems because the keyboard and monitor cannot be positioned separately, which makes them difficult to handle at the bedside.
Use a posture-enhancing adjustable chair to accommodate the sonographer through adjustable foot-rests, seat heights, and lock and release casters. Casters should allow for rolling between patients and the ultrasound machine when necessary, yet prevent rolling backwards when performing necessary procedures.
Use motorized adjustable tables (including those equipped with drop-down side rails) to optimize the positions of the patient and the sonographer. The table should be as narrow as possible (preferably 24 to 27 inches wide) to allow for proximity to the patient and to reduce the amount of shoulder abduction needed to reach the patient's far side.

Work Practices

Decrease the duration of static posturing:

— Vary postures throughout the day.
— Sit or stand, depending on the exam.

Decrease hand-grip pressure:

— Alternate the scanning hand and vary the grip used.
— Take short breaks.
— Loosen grip on the transducer.

Minimize awkward and extreme postures.
Increase tissue tolerances through exercise and adequate rest.

Scheduling

Schedule different types of exams for each sonographer in a workday to decrease strain on musculoskeletal tissues specific to one type of exam.
Limit the number of portable exams to help minimize those tasks with a higher number of pinch grips and increased static or awkward postures.
Consider a maximum number of scheduled exams for sonographers. Take into account existing ergonomic conditions and equipment, the type of exams performed, experience of the sonographer, and the duration of the individual exams. Because of the complexity of each diagnostic situation, it is difficult to specify an allowable limit to the number of exams per day. Until better information is obtained, take into account the total examination time per day (more exams of shorter duration or fewer exams of longer duration).

Training

Periodic training and reassessment regarding the above ergonomic interventions should include the following:

Setting up the equipment, bed, and chair.
Modifying the equipment positioning during scanning.
Positioning patients.
Using adaptive equipment or devices, such as cushions and wedges, and the patient's limbs for resting the elbows during scans.
Taking rest breaks during the procedures.
Maintaining good physical fitness and conditioning.
Optimal handling of specialized tests such as transvaginal examinations.
Having symptoms promptly evaluated by a licensed health care provider.

"Hopefully, this will get out to even more people than ever before," says Habes. After all, she adds, it's not like meatpackers, who may simply change jobs if they begin to feel pain. Sonographers "were educated to perform these procedures for a long period of time, much like any other career," he says. Even perinatalogists, who do some hands-on imaging after the sonographers complete their exam, have suffered injuries from the awkward postures and forces, he says.

Thanks to changes in design, the tools now are available to modify the work environment for sonographers and reduce the risk of injury, notes Joan Baker, MSR, RDMS, RDCS, FSDMS, a former sonographer and director of global marketing for Sound Ergonomics, a consulting firm based in Kenmore, WA. Manufacturers have created user-friendly equipment, but "it takes another decade to get that equipment integrated into the workplace," she says.

When hospitals purchase new sonography equipment or chairs or beds for sonography exam rooms, they should consider the impact on the sonographers and physicians, she says.

Sonographers need short breaks

In 1999, Habes and NIOSH colleague Sherry Baron, MD, MPH, responded to a request for a health hazard evaluation at St. Peter's University Hospital, which is affiliated with the University of Medicine and Dentistry of New Jersey. They videotaped several procedures and gave the sonographers symptom surveys that asked about pain or discomfort.

The sonographers performed about 10 extensive high-resolution ultrasound exams each day, which lasted an average of 18.5 minutes. They allowed themselves little release from the exertion during the exams.

"[E]rgonomics guidelines suggest that a rest period equal to the length of the sustained muscle exertion should take place before the exertion is repeated," Habes and Baron found, but video analysis revealed that "recovery times were never more than just a few seconds."

Meanwhile, the exam rooms had different configurations, with beds that were not height-adjustable. "Many of the factors associated with physical stress to the workers were related to the design and lack of adjustability of work station components and equipment," Habes and Baron wrote.

The sonographers could reduce some stresses by reconfiguring their workspace or posture, but they were reluctant to ask the patients to move, the evaluation showed. "Many of the technologists performed the procedures with total regard for the patient and little for themselves. They rarely asked the patient to move up or down or to lower her leg to improve their own postures or to rest their arm on the patient's leg or the edge of the bed," Habes and Baron found.

They recommended adjustable chairs and beds, elbow supports, sit/stand stools, changes in the position of the monitors, and short rest breaks during an exam.

Some education is in order, as well: The sonographers may not realize how their awkward positions cause musculoskeletal discomfort, says Habes. "I was surprised that the workers themselves could not relate the specific things they were doing to their problems," he says.