DOI: 10.1148/rg.242035089
RadioGraphics 2004;24:615-627
© RSNA, 2004
Importance and Effects of Altered Workplace Ergonomics in Modern Radiology Suites1
Mukesh G. Harisinghani, MD,
Michael A. Blake, FFR(RCSI), FRCR,
Mansi Saksena, MD,
Peter F. Hahn, MD, PhD,
Debra Gervais, MD,
Michael Zalis, MD,
Leonor da Silva Dias Fernandes, MD and
Peter R. Mueller, MD
1 From the Department of Radiology, Division of Abdominal Imaging & Intervention, Massachusetts General Hospital, 55 Fruit St, White 289, Boston, MA 02114. Presented as an infoRAD exhibit at the 2002 RSNA scientific assembly. Received March 31, 2003; revision requested June 10 and received August 11; accepted August 18. Address correspondence to M.G.H. (e-mail: mharisinghani@partners.org).
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Abstract
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The transition from a film-based to a filmless soft-copy picture archiving and communication system (PACS)–based environment has resulted in improved work flow as well as increased productivity, diagnostic accuracy, and job satisfaction. Adapting to this filmless environment in an efficient manner requires seamless integration of various components such as PACS workstations, the Internet and hospital intranet, speech recognition software, paperless electronic hospital medical records, e-mail, office software, and telecommunications. However, the importance of optimizing workplace ergonomics has received little attention. Factors such as the position of the work chair, workstation table, keyboard, mouse, and monitors, along with monitor refresh rates and ambient room lighting, have become secondary considerations. Paying close attention to the basics of workplace ergonomics can go a long way in increasing productivity and reducing fatigue, thus allowing full realization of the potential benefits of a PACS. Optimization of workplace ergonomics should be considered in the basic design of any modern radiology suite.
© RSNA, 2004
Index Terms: Radiology and radiologists, design of radiological facilities • Workstation
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Introduction
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Picture archiving and communication systems (PACS) have revolutionized the practice of radiology. Filmless reading rooms are becoming the norm as technologic advances such as an integrated speech recognition system, faster networks, improved workstations, and user-friendly software improve both the efficiency and the productivity of modern day radiology practices (1). However, as traditional radiology reading rooms are rapidly being converted into filmless soft-copy reading rooms, little or no attention is being paid to reading room design—that is, to the ergonomics of the radiology workplace. Ergonomics is the applied science of designing and arranging things that people use so that the people can use these things with maximum efficiency and safety.
A radiologist working in a filmless reading room needs access not only to the PACS workstation but also to ancillary equipment such as the speech recognition system, hospital medical record system, telephone, hospital paging system, hospital intranet, and Internet (Fig 1). Such access calls for either an ergonomically designed integrated single workstation with multitasking capabilities or multiple platforms that are ergonomically situated. Lack of attention to ergo-nomic design not only decreases efficiency and productivity but can actually cause harm in the form of repetitive stress injury, eye strain, backache, and shoulder and neck pain (2).
In this article, we discuss and illustrate the ergonomic deficiencies that commonly exist in the current PACS environment with respect to vision, posture (head, hands, back), temperature and ventilation, sound, and ambient lighting. For each category, we review ergonomic challenges, discuss injury potential, and propose possible solutions.
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Vision
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Every radiologist spends hours gazing at the PACS monitor and ancillary video display terminal. Each terminal can be placed at varying distances and angles relative to the eye. Many factors affect the optimal ergonomic placement of these monitors (3).
Ergonomic challenges include monitors that are placed too high (Fig 2a) or too close (Fig 2b) or are inadequately adjusted. Glare from surrounding lights or bright outdoor lighting or inadequate contrast (ie, a dark screen surrounded by a bright wall) can also present difficulties. The radiologist may have to twist the neck constantly to see various images (Fig 2c) or read continuously without a break, resulting in prolonged near focusing.
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Figure 2a. Monitor placement. (a) If the PACS monitor is placed too high, the radiologist must extend the neck, which may cause fatigue and pain. (b) If the PACS monitor is placed too close to the radiologist, he or she may experience increased eye strain and fatigue. (c) Improper seating of the radiologist and poor positioning of the PACS monitor results in repetitive neck twisting and undue muscle strain. (d, e) It is currently recommended that the top edge of the PACS monitor be 15°-50° below eye level (black line in d). Alternatively, the monitor can be placed as shown in e to achieve the recommended viewing angle. This position is better suited for simultaneous interaction with patients and computer-related processes and reduces eye and neck strain.
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Figure 2b. Monitor placement. (a) If the PACS monitor is placed too high, the radiologist must extend the neck, which may cause fatigue and pain. (b) If the PACS monitor is placed too close to the radiologist, he or she may experience increased eye strain and fatigue. (c) Improper seating of the radiologist and poor positioning of the PACS monitor results in repetitive neck twisting and undue muscle strain. (d, e) It is currently recommended that the top edge of the PACS monitor be 15°-50° below eye level (black line in d). Alternatively, the monitor can be placed as shown in e to achieve the recommended viewing angle. This position is better suited for simultaneous interaction with patients and computer-related processes and reduces eye and neck strain.
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Figure 2c. Monitor placement. (a) If the PACS monitor is placed too high, the radiologist must extend the neck, which may cause fatigue and pain. (b) If the PACS monitor is placed too close to the radiologist, he or she may experience increased eye strain and fatigue. (c) Improper seating of the radiologist and poor positioning of the PACS monitor results in repetitive neck twisting and undue muscle strain. (d, e) It is currently recommended that the top edge of the PACS monitor be 15°-50° below eye level (black line in d). Alternatively, the monitor can be placed as shown in e to achieve the recommended viewing angle. This position is better suited for simultaneous interaction with patients and computer-related processes and reduces eye and neck strain.
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Figure 2d. Monitor placement. (a) If the PACS monitor is placed too high, the radiologist must extend the neck, which may cause fatigue and pain. (b) If the PACS monitor is placed too close to the radiologist, he or she may experience increased eye strain and fatigue. (c) Improper seating of the radiologist and poor positioning of the PACS monitor results in repetitive neck twisting and undue muscle strain. (d, e) It is currently recommended that the top edge of the PACS monitor be 15°-50° below eye level (black line in d). Alternatively, the monitor can be placed as shown in e to achieve the recommended viewing angle. This position is better suited for simultaneous interaction with patients and computer-related processes and reduces eye and neck strain.
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Figure 2e. Monitor placement. (a) If the PACS monitor is placed too high, the radiologist must extend the neck, which may cause fatigue and pain. (b) If the PACS monitor is placed too close to the radiologist, he or she may experience increased eye strain and fatigue. (c) Improper seating of the radiologist and poor positioning of the PACS monitor results in repetitive neck twisting and undue muscle strain. (d, e) It is currently recommended that the top edge of the PACS monitor be 15°-50° below eye level (black line in d). Alternatively, the monitor can be placed as shown in e to achieve the recommended viewing angle. This position is better suited for simultaneous interaction with patients and computer-related processes and reduces eye and neck strain.
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Increased vision-related problems such as eye strain, irritation and fatigue, and constant headache may arise. Some of the symptoms associated with increased eye strain include sore, tired, itchy, dry, or burning eyes; headaches; difficulty in refocusing as one looks from the video display terminal to source documents and back; blurred or double vision; color fringes after images; and photophobia.
The top edge of the display terminal should be no higher than eye level. In fact, the current recommendation is for the top edge to be 15°–50° below eye level (Fig 2d, 2e) (4). The eye-to-screen distance should be at least 25 inches and preferably greater. The resting point of vergence (RPV) is the distance at which the lines of sight for the two eyes converge when there is nothing to gaze at (eg, in total darkness). The RPV varies among individuals but averages about 45 inches when looking straight ahead and 35 inches with a 30° downward gaze angle (4). Viewing objects farther than the RPV has not been found to cause any problems. For viewing objects closer than the RPV, "farther is better." If you can read the monitor, it is not too far away. If you cannot read the characters, it is preferable to make them larger (by increasing the displayed font size) than to bring the monitor closer. The top of the monitor should be slightly farther from the eyes than the bottom of the monitor. The lighting should be indirect and glare free, irrespective of whether it is wall-mounted or ceiling-suspended lighting. Blinds and shades should be used to control outside lighting. Frequent short breaks are generally suggested to optimize performance and minimize fatigue; a reasonable but not yet scientifically proved strategy would be to look 20 feet away for 20 seconds every 20 minutes.
The two most common types of monitors in use today are cathode ray tube (CRT) monitors and liquid crystal display (LCD) monitors. CRT and LCD monitors are based on completely different technologies and thus have quite different display characteristics. Newer generation, higher brightness, active matrix LCD displays should be preferred for general purposes (5). Monitor specifications that must be adjusted to minimize eye strain include the refresh rate, which refers to the speed at which a screen is refreshed or updated. The vertical scan rate is expressed in hertz and tells how many times per second the screen is repainted from top to bottom. The higher the vertical scan rate, the less flicker can be noticed on the screen. The standard for a flicker-free CRT display is a vertical scan rate of 75 Hz or higher (Fig 3).
LCD monitors offer several advantages over conventional CRT monitors. (a) LCD monitors are compact and lightweight, taking up less desktop space (Fig 4a). However, a CRT screen can be looked at from a very wide angle—nearly from the side—whereas an LCD monitor typically has a smaller viewing angle and must be viewed more directly from the front (Fig 4b), although newer LCD displays with wider viewing angles are beginning to appear on the market. (b) LCD monitors consume much less energy than CRT monitors, which makes the former great for laptop and portable computers. (c) LCD monitors emit lesser amounts of potentially harmful radiation than do CRT monitors.
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Figure 4a. Comparison of LCD and CRT monitors. (a) Drawing illustrates how an LCD monitor (light area) with its compact design occupies far less desk space than a CRT monitor (dark area). (b) Drawings of CRT (left) and LCD (right) monitors (top view) illustrate the smaller viewing angle of the LCD monitor. However, notice the narrower footprint of the LCD monitor.
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Figure 4b. Comparison of LCD and CRT monitors. (a) Drawing illustrates how an LCD monitor (light area) with its compact design occupies far less desk space than a CRT monitor (dark area). (b) Drawings of CRT (left) and LCD (right) monitors (top view) illustrate the smaller viewing angle of the LCD monitor. However, notice the narrower footprint of the LCD monitor.
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Posture
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Head
The human head weighs approximately 8–12 pounds, and any nonneutral position demands considerable work from the neck muscles as they continuously try to balance the head. The increased strain can also compress the neck vertebrae. Users often twist the neck to look at documents, bend it down to type, and tilt it upward or sideways to look at improperly placed monitors.
Repeatedly looking at reference materials placed to the side of the primary viewing screen (Fig 5) and looking at a keyboard for prolonged periods of time (Fig 6) pose challenges.
Other problems include overly high monitor placement, which requires the user to tilt the head back to look at the monitor (Fig 2a), or continuously working at the computer with no breaks.
Tilting the head back to look at the screen or reference material leads to tension in the neck muscles, which can cause neck and shoulder pain. Continuous tension in the neck muscles may lead to headaches. Repeated twisting of the neck will compound the problem.
Any computer station that is used for more than 2 hours a day should be reorganized so that the monitor and keyboard are directly in front of the user (Fig 7).
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Figure 7. Optimal positioning of the PACS monitor and keyboard directly in front of the radiologist with an adjacent document holder results in an ergonomically sound posture, thereby minimizing neck and upper back strain.
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The neck should always be in a neutral position while the user is looking at the monitor. A document holder should be used to position the reference material as close to the screen as possible (Fig 7). One should learn to touch type, but if one has to look down at the keyboard frequently, the screen should be lowered slightly, thereby reducing the nodding motion caused by continuously looking from the keyboard to the screen and back.
Hands
Poor position vis-à-vis the keyboard is a common source of ergonomic error and results in poor positioning of the shoulders, elbows, and wrists. If the elbows are held away from the body, the muscles in the neck, shoulders, and upper arms are under constant static load. In addition, there is an angle through the wrist (when viewed from above).
Problems arise if there are no elbow rests, which causes the elbows to hang downward (Fig 8a). Sitting too close to the keyboard causes the arms to be held away from the sides (Fig 8b), whereas sitting too far from the keyboard causes the arms to be overextended (Fig 8c). Keeping reference material in front of the keyboard forces one to stretch for the keyboard while typing. Keeping the monitor and keyboard at an angle causes the wrists to be at a bad angle when one is using the keyboard (Fig 8d). In addition, the keyboard tray may be either too high or too low, and keeping the mouse too far from the keyboard causes undue stretch when the mouse is being used (Fig 8e).
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Figure 8a. Hand posture. (a) Absence of elbow rests causes the elbows to hang downward. (b) Sitting too close to the keyboard causes the arms to be raised to the sides. (c) Sitting too far from the keyboard causes the arms to be overextended. (d) Keeping the monitor and keyboard at an angle creates a bad angle for the wrists. (e) Keeping the mouse far from the keyboard causes undue stretch during use. (f) With optimal posture, the upper arms are relaxed at the sides with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms (black lines).
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Figure 8b. Hand posture. (a) Absence of elbow rests causes the elbows to hang downward. (b) Sitting too close to the keyboard causes the arms to be raised to the sides. (c) Sitting too far from the keyboard causes the arms to be overextended. (d) Keeping the monitor and keyboard at an angle creates a bad angle for the wrists. (e) Keeping the mouse far from the keyboard causes undue stretch during use. (f) With optimal posture, the upper arms are relaxed at the sides with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms (black lines).
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Figure 8c. Hand posture. (a) Absence of elbow rests causes the elbows to hang downward. (b) Sitting too close to the keyboard causes the arms to be raised to the sides. (c) Sitting too far from the keyboard causes the arms to be overextended. (d) Keeping the monitor and keyboard at an angle creates a bad angle for the wrists. (e) Keeping the mouse far from the keyboard causes undue stretch during use. (f) With optimal posture, the upper arms are relaxed at the sides with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms (black lines).
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Figure 8d. Hand posture. (a) Absence of elbow rests causes the elbows to hang downward. (b) Sitting too close to the keyboard causes the arms to be raised to the sides. (c) Sitting too far from the keyboard causes the arms to be overextended. (d) Keeping the monitor and keyboard at an angle creates a bad angle for the wrists. (e) Keeping the mouse far from the keyboard causes undue stretch during use. (f) With optimal posture, the upper arms are relaxed at the sides with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms (black lines).
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Figure 8e. Hand posture. (a) Absence of elbow rests causes the elbows to hang downward. (b) Sitting too close to the keyboard causes the arms to be raised to the sides. (c) Sitting too far from the keyboard causes the arms to be overextended. (d) Keeping the monitor and keyboard at an angle creates a bad angle for the wrists. (e) Keeping the mouse far from the keyboard causes undue stretch during use. (f) With optimal posture, the upper arms are relaxed at the sides with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms (black lines).
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Figure 8f. Hand posture. (a) Absence of elbow rests causes the elbows to hang downward. (b) Sitting too close to the keyboard causes the arms to be raised to the sides. (c) Sitting too far from the keyboard causes the arms to be overextended. (d) Keeping the monitor and keyboard at an angle creates a bad angle for the wrists. (e) Keeping the mouse far from the keyboard causes undue stretch during use. (f) With optimal posture, the upper arms are relaxed at the sides with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms (black lines).
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The constant static load on the neck and shoulder muscles can result in chronic pain in the upper back, shoulders, and neck. An awkward hand angle causes the nerves running through the wrist to rub against the surrounding ligaments and bone, leading to repetitive stress injuries or cumulative trauma disorders (eg, carpal tunnel syndrome) and various kinds of tendon inflammation.
The upper arms should be in a relaxed position at the sides, with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms. Elbow rests are helpful for maintaining this posture (Fig 8f). The distance from the keyboard should be adjusted until one can work with the shoulders and arms in a relaxed position. The keyboard should be situated parallel to the edge of the desk when in use. Placement of documents in front of the keyboard should be avoided. The mouse must be placed close to the keyboard for combined keying and mouse use, and, whenever possible, keyboard shortcuts should be used instead of the mouse.
If possible, one should alternate hands in using the mouse. Finally, the mouse and mouse pad must be kept clean so that the extra time spent holding the mouse and making small adjustments can be minimized.
Back
As with many other things, with the radiologist’s chair, "one size does not fit all." Yet, in a busy reading room, people will often pull up the closest chair and then proceed to slouch on it for hours with poor back posture. When a radiologist sits down, the inward curve of the lower back flattens or even reverses, which puts pressure on the intervertebral disks. A few minutes spent adjusting the chair to meet one’s specific needs can go a long way in making the job less "painful."
Problems arise from sitting with bad posture (eg, slouching) (Fig 9a) or with inadequate backrests that do not provide much-needed support for the lower back. An overly high chair causes the radiologist to either slide forward or sit upright with the back unsupported (Fig 9b, 9c), and an oversized cushion digs into the back of the knees.
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Figure 9a. Back posture. (a) Slouching constitutes suboptimal and ergonomically poor posture and puts undue strain on the lower back and intervertebral disk spaces. (b, c) A chair that is adjusted too high may cause the radiologist to either slide forward or slump (b) or to sit upright with the back unsupported and the ankle joints hyperextended (c). Note also the inadequate lower back support resulting from improper placement of the backrest. (d) Proper placement of the backrest offers good lumbar ergonomics, precluding injury to the lower back.
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Figure 9b. Back posture. (a) Slouching constitutes suboptimal and ergonomically poor posture and puts undue strain on the lower back and intervertebral disk spaces. (b, c) A chair that is adjusted too high may cause the radiologist to either slide forward or slump (b) or to sit upright with the back unsupported and the ankle joints hyperextended (c). Note also the inadequate lower back support resulting from improper placement of the backrest. (d) Proper placement of the backrest offers good lumbar ergonomics, precluding injury to the lower back.
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Figure 9c. Back posture. (a) Slouching constitutes suboptimal and ergonomically poor posture and puts undue strain on the lower back and intervertebral disk spaces. (b, c) A chair that is adjusted too high may cause the radiologist to either slide forward or slump (b) or to sit upright with the back unsupported and the ankle joints hyperextended (c). Note also the inadequate lower back support resulting from improper placement of the backrest. (d) Proper placement of the backrest offers good lumbar ergonomics, precluding injury to the lower back.
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Figure 9d. Back posture. (a) Slouching constitutes suboptimal and ergonomically poor posture and puts undue strain on the lower back and intervertebral disk spaces. (b, c) A chair that is adjusted too high may cause the radiologist to either slide forward or slump (b) or to sit upright with the back unsupported and the ankle joints hyperextended (c). Note also the inadequate lower back support resulting from improper placement of the backrest. (d) Proper placement of the backrest offers good lumbar ergonomics, precluding injury to the lower back.
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Slouching causes the spine to curve outward, putting pressure on the intervertebral disks and possibly leading to acute or chronic back pain.
Every effort should be made to sit upright. The backrest on the chair should be adjusted to provide support for the lower spine. One should make sure that the seat cushion is neither too long nor too short and should be able to sit fully back in the seat without the front of the cushion pinching the back of the knees. Small adjustments in posture should be made throughout the day to relieve any tension on the lower back muscles. A footrest should be used if the chair is too high. If more lower back support is needed and purchasing a new chair is not an option, a lumbar support may be used (Fig 9d).
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Temperature and Ventilation
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The increased power requirements associated with computer workstations and monitors tends to raise the temperature in a filmless reading room. Electrical equipment not only generates heat but also dries the air. The resulting static build-up attracts dust that can irritate the eyes, nose, and throat. The most comfortable temperature for sedentary work is between 20 and 24°C (68°–75°F), with a relative humidity between 40% and 60%. However, this ideal is seldom achieved in the average filmless reading room with its numerous workstations.
As traditional film reading rooms are converted to filmless reading areas, there is no accompanying increase in air conditioning capacity. The generated heat may overwhelm the air conditioning system, resulting in increased heat and poor ventilation (6). Lack of individual controls for temperature and ventilation is another issue, because what feels hot to one person may feel cold to another.
Increased fatigue may result in decreased efficiency and productivity and increased frequency and duration of the radiologist’s "coffee breaks." Damage to electronic equipment can also occur, with decreased life of monitors and other components.
An increased-capacity air conditioning system should be included in the planning of any PACS reading room. Old air conditioning systems should be renovated. Individual controls for temperature and ventilation (similar to those in most automobiles) should be installed at each workstation. Appropriate clothing must be worn. One should consider introducing water-loving plants (eg, the bamboo family) into the work area, which helps control humidity.
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Sound
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A large filmless reading room in which many radiologists sit close together and dictate reports can create objectionable levels of ambient noise (Fig 10a). Computer workstations, consultations by telephone or in person, air conditioning noise, and overhead paging systems all contribute to the ambient noise and may cause fatigue and decreased productivity (5).
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Figure 10a. Sound-related ergonomics. (a) A large filmless reading room with many radiologists sitting close together and dictating reports can lead to objectionable levels of ambient noise. (b) Multiple dictation stations placed close together with no dividing panels can lead to increased noise levels that may adversely affect productivity and efficiency.
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Figure 10b. Sound-related ergonomics. (a) A large filmless reading room with many radiologists sitting close together and dictating reports can lead to objectionable levels of ambient noise. (b) Multiple dictation stations placed close together with no dividing panels can lead to increased noise levels that may adversely affect productivity and efficiency.
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Multiple dictation stations placed close together with no dividing panels can lead to a noisy, distracting environment (6) (Fig 10b). Other factors include the absence of acoustic dampening materials such as carpeting and sound-absorbing ceiling panels in the reading room. PACS workstations placed in other areas (eg, an emergency department) without appropriate isolation may subject radiologists to unnecessary background noise.
High levels of ambient sound hamper concentration and increase fatigue, and unwanted background noise can decrease the accuracy of computer voice recognition systems used for dictating reports.
Acoustic dampening materials such as carpeting and sound-absorbing panels may be useful in filmless reading rooms (6). Noisy equipment such as printers and copiers should be placed away from the radiology reading areas. Regular servicing of equipment such as fans and air conditioners is recommended to ensure efficient, noiseless functioning.
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Ambient Lighting
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The old film reading rooms had bright light boxes with an output ranging from 500 to 1,000 foot lamberts. Now, however, typical high-resolution 5-megapixel PACS monitors have an output in the range of 60–70 lamberts, a level that represents one-tenth of that of a conventional light box (6). Therefore, the relative balance between monitor light output and background reading room lighting plays an important role in determining the degree of radiologist fatigue as well as efficiency and accuracy.
The use of overhead fluorescent lighting markedly increases ambient light levels (5). Lack of individual control over the ambient lighting in the reading room means that if a radiologist at one workstation is reading from conventional paper or reading films while another radiologist at an adjacent workstation is viewing images on the monitor, the ambient lighting cannot be ideal for both tasks (Fig 11). Lack of partitions between workstations clearly also poses lighting challenges.
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Figure 11. Lack of individual control over the ambient lighting in a reading room can hamper the performance of simultaneous tasks by different radiologists. In this photograph, the lighting that allows one radiologist to write adversely affects the other radiologist’s ability to read studies on the PACS monitor.
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Decreased radiologist productivity (increased interpretation times), increased fatigue, and decreased accuracy can all result from suboptimal ambient lighting.
On-off light switches should be located near each workstation, with individual dimmers to enable users to adjust the lighting depending on the task being performed. Partially covered conventional light boxes should not be used as a source of ambient light. A combination of indirect overhead lighting and local task lighting should be used. Moveable partitions should be installed between workstations, and walls can be painted dark to avoid reflection.
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Designing an Ergonomically Optimal PACS and Ancillary Workstation
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Paying close attention to detail in setting up a PACS workstation will reduce most causes of pain and discomfort. The following steps should be taken to achieve an ergonomically sound working environment.
1. First, adjust the chair height so that when the fingers are placed on the middle row of the keyboard, the forearms and hands are horizontal, with the elbows directly under the shoulders and no angle formed at the wrist (Fig 12).
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Figure 12. Optimal chair height. The height should be adjusted so that the forearms and hands are horizontal, with the elbows directly under the shoulders and no angle formed at the wrist.
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2. If the undersides of the thighs are compressed, either a footrest or a lower desk is needed. Most desks in the old film reading rooms were of a standard height of about 710 mm (obviously standardized before the development of PACS). If these desks are still in use, as is the case in most centers, most users will benefit from a footrest (Fig 13). Desk height may be hard to change, but footrests can easily be purchased or even made from a box, board, cushion, or piece of stiff foam. Adjustable computer desks and chairs are now available, both of which can be useful if adjusted properly.
3. Adjust the angle of the backrest or the length of the seat cushion so that the lower back is supported, taking care to ensure that the seat cushion is not too long (Fig 14).
4. Adjust the height of the backrest so that it supports the lower back. Most radiologists set the back support either too low or not at all and thus often sit at an inappropriate angle. Sit very upright. If the shape of the backrest does not fit fully into the small of the back, consider obtaining a back support. Move the chair so that the elbows are directly under the shoulders during keyboard use. Fixed-height armrests are generally too low, often causing the user to slump down to use them. Adjustable-height armrests are usually shorter and will allow the user to sit close enough to the desk while offering valuable support, taking some of the weight of the arms off the shoulder and neck muscles (Fig 15). Short but fixed armrests can be raised by wrapping foam around them or by adding a layer of foam and wrapping fabric around the foam and the armrest.
Check the distance of the monitor. For most people, the screen should be about 22–26 inches (55–65 cm) away so that the eye focus muscles do not have to work too hard (Fig 16). Sitting much closer than this may indicate an eyesight problem, suboptimal monitor quality or settings, or a desk that is too narrow. Usable desk depth can often be increased by pulling the desk away from the wall and allowing the monitor to overhang at the back. Check the side-to-side position of the monitor; the monitor should be directly in front of the user (Fig 17). Never put the monitor in the corner, which will either make it hard to get close enough to the keyboard or require twisting of the body, which can result in back and neck problems. The document holder should be placed at about the same height and distance as the monitor screen to minimize head movement when the user looks from the document to the screen and back. The screen and the document holder should be the same distance from the eyes to avoid constant changes of focus and close enough to each other so that the operator can look back and forth without excessive neck or back movement. Sit close to the desk with nothing between you and the keyboard except a wrist rest; the elbows need to be directly under the shoulders. The far side of the keyboard should be lifted only if the elbows are below desk height.
5. Position and use the mouse as close to the body as possible. Aim to have the elbow directly under the shoulder and close to the body or on an armrest (Fig 18).
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Figure 18. The mouse should be positioned and manipulated as close to the user as possible. The elbow should be positioned directly under the shoulder and right by the side or on the armrest.
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6. A document holder should be used for documents such as references. The holder should be positioned at the same height and distance as the monitor to avoid unnecessary vertical movement of the head and thus to minimize stress on the neck muscles.
7. Eliminate any glare or reflections from the monitor. Try closing blinds and changing the position of the workstation so that the monitor is at right angles to the window. If the monitor is of the CRT type, optimal refresh rates need to be selected to reduce eye fatigue.
8. Position any additional equipment or materials (eg, telephones, paper trays, reference material) in accessible places. Try to avoid reaching and twisting.
9. Adjust the temperature, humidity, ventilation, and ambient lighting for maximum comfort.
10. In summary, while at work, remember to (a) work in "neutral," (b) use good posture, and (c) change position often.
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Conclusions
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Paying close attention to the basics of workplace ergonomics can go a long way in increasing productivity and reducing fatigue, so that the potential benefits of a PACS can be fully realized. Optimization of workplace ergonomics should be a consideration in the basic design of any modern radiology suite (Figs 19, 20).
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Footnotes
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Abbreviations: CRT = cathode ray tube,
LCD = liquid crystal display,
PACS = picture archiving and communication system,
RPV = resting point of vergence
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References
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- Reiner BI, Siegel EL, Hooper FJ, Pomerantz S, Dahlke A, Rallis D. Radiologists’ productivity in the interpretation of CT scans: a comparison of PACS with conventional film. AJR Am J Roentgenol 2001; 176:861-864.[Abstract/Free Full Text]
- Carter JB, Banister EW. Musculoskeletal problems in VDT work: a review. Ergonomics 1994; 37:1623-1648.[Medline]
- Ishihara S, Shimamoto K, Ikeda M, et al. CRT diagnosis of pulmonary disease: influence of monitor brightness and room illuminance on observer performance. Comput Med Imaging Graph 2002; 26:181-185.[CrossRef][Medline]
- Burgess-Limerick R, Plooy A, Ankrum DR. The effect of imposed and self-selected computer monitor height on posture and gaze angle. Clin Biomech (Bristol, Avon) 1998; 13:584-592.[CrossRef]
- Siegel E, Reiner B, Abiri M, et al. The filmless radiology reading room: a survey of established picture archiving and communication system sites. J Digit Imaging 2000; 13:22-23.[Medline]
- Siegel E, Reiner B. Radiology reading room design: the next generation. Appl Radiol 2002; 4:11-16.
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Abstract
Introduction
