Work-related musculoskeletal injury (WRMSI) has been studied and documented extensively in many professions over the past two decades. This study intensified in the early 1990’s as downsizing and rightsizing became a popular way for corporations to improve their profitability. The resulting intensification of work demands with resultant increases in incidence of WRMSI stimulated efforts to better define the relationship between work activities and WRMSI incidence. Numerous surveys by different authors were sent out to collect data on occupational injury. These were typically research oriented, local in scope and tended to be small in terms of the number of surveyed participants. What was interesting about these surveys was that many reported a very high incidence of occupational injury in diagnostic medical sonographers.

The Society of Diagnostic Medical Sonography (SDMS) was also receiving reports of WRMSI in sonographers and this prompted them to pay for a large survey. In late 1996 through early 1997 a survey was conducted using 3000 sonographers randomly selected from the American Registry Diagnostic Medical Sonographers (ARDMS) data base. The survey was funded by the SDMS, Canadian Society of Diagnostic Medical Sonographers (CSDMS), and the British Columbia Ultrasound Society (BCUS).

The data indicated that the majority of injuries were in the neck and shoulder, closely followed by the wrist and back. It is important to also note the amount of eyestrain since this leads to compensatory bad posture and further injury. Many of those responding to the survey stated that they suffered from headaches and blurred vision due to inadequate lighting. As might be expected from the nature of the work sonographers perform, the occurrence of reported pain is highest for the neck, shoulders and upper back (Figure 1).

Figure 1: Distribution of complaints by body region

The goals of this survey were to:

• Determine prevalence of MSI and correlate known work and personal factors.
• Develop instruments, protocols and methods to quantify risks.
• Design and test interventions
• Recommend work load/procedural changes.
• Recommend modification or redesign of equipment and/or environment.

The survey was a 21-page questionnaire divided into 5 sections.

• Section 1
• Work experience
• General Health
• Background Information
• Questions on age, gender,
• smoking, wearing of lenses
• state of health, exercise habits,
• hobbies
• Section 2
• Work schedule and tasks
• Section 3
• Work equipment
• Section 4
• Problems, pain and discomfort
• Section 5
• Work environment and corporate culture

The questionnaire was returned from 983 out of 3000 sonographers from the United States, for a 33% return rate. Two hundred and eleven out of 232 sonographers from British Columbia returned the survey for an outstanding return rate of 92%. The questionnaire was piloted in British Columbia but was not changed making it possible to include the data in the final statistics. The survey was also mailed to all Canadian sonographers except those living in British Columbia and 427 out of 1088 were returned for a 39% response rate. The grand total of returned questionnaires was 1,621. The data was published in a paper published in JDMS 13:219-227 Sept/Oct, 1997, authored by Pike, Russo, Berkowitz, Baker, and Lessoway.

RESULTS OF THE SURVEY:
The average time of actual scanning is 17.8 days per month and 6.8 hours per day. The average length of a work day, not including “on-call” was 8.3 hours. Fifty-seven percent of sonographers scanned while seated. Risk factors for injury are related not only to how much time is spent holding a transducer and exerting force but also to the time spent in a static position. The survey showed that 30 % of respondents typically maintained static posture during scanning for less than 10 minutes, 31.4% for 10-15 minutes and 29.1% for 15-30 minutes. Over 30 minutes accounted for 9.5%.

When asked to describe the pain they experienced:

• 90% reported an aching feeling
• 56% experienced stiffness
• 40% reported sharp pain or cramping
• 33% had weakness, numbness or burning

Of those reporting pain

• 55% saw a physician / medical professional
• Of these, 81.7% received diagnosis, however only 45.8% received any kind of treatment

Of those receiving treatment

• 67.7% said it had been moderately or very effective
• 28.3% said the treatment had been slightly effective
• 4.0% reported no treatment effect

In general, sonographers have a positive perception of their work environment and corporate culture. However, respondents indicated they had some concerns over work schedule, work tasks and lack of support services.

Work environment concerns included:

• Inability to schedule overtime or extra work in advance (61%)
• Inability to take scheduled breaks (56%)
• Lack of control over work (54%)
• Repetitive work tasks (61%)
• Lack of work schedule support (40%)
• Lack of helpful personal development support services (40%)

Eighty-four percent of respondents reported they had experienced pain or discomfort since starting work as a sonographer

• 81% from the SDMS study
• 87.2% from the CSDMS study
• 91% from the BCUS study

Of these, 96.5% thought it was related to scanning, 88.9% still experience pain or discomfort and had done so for an average of 5 years (58.068 months). The average length of time the respondents had been in the profession was 11 years.

Figure 2: Age distribution of respondents

Data from the same survey showed that the average age of practicing sonographers who responded to the study is 42 years and that 80% of respondents were between the ages of 30 and 50, and 11.5% were under 30 years of age (Figure 2). Sonography is typically not a first career for most sonographers and the average length of time that the respondents had been in the field was 11 years. There is a higher incidence of musculoskeletal complaints in the chronologically older population which may account for part of the problem found. However, force, duration, static position, equipment design, lack of education on risk factors by the end user and workstation design are more likely to be the cause of the international problem.

Figure 3: Incidence of "severe" pain as a subset of those reporting pain.

Research on WRMSI in other professions has shown a direct correlation between the length of time that work activity associated with MSI is sustained and both the incidence and severity of WRMSI. Many types of WRMSI can be greatly reduced by introducing interruptions to sustained activity, in the form of rest breaks or by modifying the work flow to incorporate activities which use different muscles and joints, thus giving the body time to recover from potentially injurious activity. The number of breaks which sonographers are able to take during the work day thus becomes a critical factor. The survey highlighted this as a major problem (Figure 4).

Figure 4: Number of breaks during the work day.

Figure 4 shows the number of breaks of 10 minutes or more per day on average that the respondent sonographers reported. Over half reported receiving no breaks during the work day. This is important because breaks provide opportunity for the muscles and tendons to recover from sustained use.

Figure 5: Activities associated with pain.

Respondents were asked to identify those activities that they felt were causative of the pain they reported experiencing and to rate these activities on a scale of 1-5 with 5 being most likely to cause pain or exacerbation of pain and 1 being least likely. The most commonly reported activities are graphed in Figure 5.

Figure 6: Impact of WRMSI

The impact of WRMSI is not limited to the workplace. Injury to muscles, tendons and joints can affect the individual’s ability to participate in recreation, household tasks, and ultimately in the ability to sustain work. Respondents were asked to indicate where they experienced pain (the top three bars of Figure 6) and whether the pain compromised their ability to engage in specified activities (the bottom 4 bars of Figure 6). It is interesting that the number of responses indicating absent from work was quite low compared with similar surveys in other professions. This most likely reflects the overall positive attitude that sonographers have about their work and that they choose to continue working even when experiencing significant pain. Contributing to this is also concern for ones co-workers who will have to pick up the work-load for the absent staff member. This causes many to work beyond the point where they should stop and get medical treatment; this may lead to an increase in the number of career ending injuries. Sonographers may also be aware of others in their department who are also suffering from similar injuries and may feel that it is inappropriate for them to seek relief by staying off work. Finally there is a significant amount of denial until pain and discomfort reaches an intolerable level.

OTHER DATA, OTHER FINDINGS: Figure 7: Volume of procedures performed per sonographer per year

The data graphed in Figure 7 was consolidated from three different sources and represents the volume of procedures per sonographer over a period of 8 years. The numbers for 1992 come from data collected by the AHRA to study manpower in radiology departments. The AHRA repeated this study in 1995. The data for 2000 came from the Sonographer Benchmark study by the SDMS and the SDMS Foundation. Figure 7 demonstrates a dramatic increase in work load for sonographers between 1995 and 2000. This is the most likely explanation for the parallel increase in the complaints about occupational injury as manpower shortages take their toll on the profession.

The data above was presented as part of written testimony to Elaine Chao the Labor Secretary under the Bush administration. Two representatives from the SDMS testified during the Clinton administration regarding occupational injury in sonographers in 1999. You may view this testimony at www.sdms.org under workzone. After the OSHA standard signed into law by Clinton was rescinded by Bush the Labor Secretary took further public testimony and the same two representatives responded on behalf of the SDMS and the sonography community.

DISCUSSION:
The high incidence of occupational injury in the field of Sonography is truly alarming. While meat cutters and bar code scanners in grocery stores are considered high-risk occupations their incidence of injury is substantially less than that for sonographers. The British Columbia survey has been repeated in Australia, Canada, and New Zealand and recently in the United Kingdom. The results of all of these surveys (Figure 8) show an equal or higher incidence rate than the United States.

Figure 8: Incidence of reported pain among sonographers by country.

Although sonographers in these countries perform ultrasound slightly differently and the type of studies they perform also differ, they are all performing procedures using essentially the same equipment, and technique. This means that something very fundamental to the process of performing ultrasound scans must be at root of this problem.

In the next article we will explore how sonographers can reduce their vulnerability to WRMSI and future articles will provide advice on taking positive action to reduce the incidence of WRMSI in the ultrasound workplace.

Sonographers and physicians who scan can reduce their vulnerability to WRMSD through education. It is imperative to know the risk factors for occupational injury if you are going to be able to reduce your risk or prevent these conditions.

One of the main risk factors is reaching. This can occur with either or both arms and can cause pain and discomfort in the shoulder and neck. To reduce reaching of the non-scanning arm pull the equipment as close as possible towards you. You should attempt to reduce the reach to no more than 30 centimeters. This requires there to be enough leg room under the scanner console to accommodate your legs. If this is not possible you need to stand to scan. Avoid keeping your arm extended over the control panel or freeze button. Reaching with your scanning arm can be avoided by positioning the patient correctly. The patient’s body should be close to the operator and the part of the patient’s body to be scanned should be in line with your shoulder. Do not scan with you arm extended behind you as this produces torque on the shoulder and requires the neck to be twisted in the opposite direction to view the monitor.

Twisting of the trunk and neck was one of the main complaints from sonographers. This is avoided by putting your weight evenly on both feet when standing and using your abdominal muscles to support your trunk when sitting. To avoid twisting of the neck position the monitor directly in front of you by bringing the equipment parallel and touching the table the patient is lying on. Do not tilt the monitor to share the image with your patient. If the patient is to be allowed to watch the study a monitor needs to be provided on the wall for their viewing.

Wrist flexion and extension is another risk factor and is often seen when sonographers do not take the time to support their wrist. Keep your wrist in a neutral position. Do not leave your wrist on the edge of the keyboard. When moving equipment push with straight wrists and avoid twisting motion of the trunk while trying to control the direction of movement of the equipment. If the equipment has wheels that can be locked in one direction, always lock the leading wheels so that you can more easily steer the equipment. If you have difficulty moving heavy equipment do not hesitate to ask for assistance and advocate for lighter equipment in future purchases.

To reduce abduction of the arm the table must be lowered and the chair raised. The goal is to reduce the angle of abduction to 30 degrees or less. To accomplish this the patient must be positioned near the edge of the table such that the patient’s side is touching the sonographer’s side.

Don’t scan like this. The table is too high and the chair too low. See how many other elements of poor ergonomics you can spot in this picture.

Do scan like this. With the table lower and the chair higher the angle of abduction is now les than 30 degrees. The patient and the machine have also been repositioned to further improve the ergonomics of the scanning process.

Many sonographers grip the transducer unnecessarily tight. The use of well fitting textured-finger gloves can also assist with this. Do not wear gloves that are too large, as this also requires more grip once the gel is applied. How tight you grip the transducer is more a result of habit than necessity. Your grip needs to be only tight enough to avoid dropping the transducer and to maintain control.

Cables should not be draped around your neck or allowed to just hang freely. A cable brace works well to prevent torque on the wrist. Select transducers with flexible, light-weight cables whenever possible.

Scan head design is very important as well as how you hold the transducer. Experiment with various ways of holding the scan head to learn how to minimize stress on structures of the hand. Avoid a pinch grip and try as much as possible to use a power grip. This will take getting used to and you will have less fine motor skill for a while but eventually you will find ways to use this grip for at least part of the study. Explore changing your grip for various parts of the scan in order to distribute stress across different muscle groups.

Make ergonomics part of the buying decision for the next piece of equipment for your lab and look for equipment features that compliment the types of scanning you most often perform.

Avoid static positions and make sure there is variety in the types of scans you do. Avoid scheduling the same type of procedures back to back whenever possible. Take mini breaks to relax your arm, hand, fingers, and neck. Take a few seconds every 8 minutes to relax before continuing the study. Do not schedule add on patients during your lunch breaks, this time is needed to reduce the stress on your muscles and tendons. Do not go from scanning to PACS and back to scanning without allowing for muscle recovery time. Take many brief breaks during the day rather than long breaks only once or twice.

By being aware of the potential for WRMSI you can make optimal choices in scheduling studies, setting a reasonable work pace, while still managing the heavy demands that all of us face in the workplace today.