Surgical Ergonomics and Preventing Work-Related Musculoskeletal Disorders

In Brief

Implementation of surgical ergonomics should be considered to avoid work-related musculoskeletal disorders, which cause disability and affect surgeons' career longevity and productivity.

A 45-year-old gynecologist feels a snap in his wrist during robotic surgery while sitting on the console. He is permanently disabled from a tendon rupture and is unable to operate again. A 44-year-old gynecologic oncologist has to take 6 weeks off work to rehabilitate lumbar disc herniation causing pain in the hips, buttocks, and down the leg. She can perform only minor surgery for the subsequent 2 months.

To become a surgeon takes years of education and rigorous training. The job is physically and mentally demanding, but, during this intense training, minimal attention is given to the potential negative effect on a surgeon's health.¹ We believe that there needs to be a paradigm shift—to view the surgeon as a high-performance athlete. For each surgical case, the surgeon must assure mental acuity and create an environment to ensure maximal physical dexterity and longevity. This culture shift begins with an ergonomic work environment in which the environment fits the worker by creating conditions for optimal surgical performance.

The health care industry has one of the highest rates of work-related injury and illness compared with other private sectors, with 582,800 cases in 2017.² This was 153,900 more cases than in manufacturing, the next highest sector.² Specific to surgery, overuse syndrome was first reported during open surgery in 1988.³ Surgeons' work environments, with awkward postures in bent, extended, or flexed positions rather than straight or neutral positions, can cause fatigue and lead to musculoskeletal injury when held for sustained periods or performed repetitively.⁴ Symptoms can start during working hours and may improve, but, with repetitive injury, they can become permanent.⁵ These work-related musculoskeletal disorders are not uncommon in surgeons and include carpal tunnel syndrome, neck tension syndrome, cervical spine disease, lumbar degenerative disease, shoulder and wrist tendonitis, rotator cuff injury, and trigger finger.^5,6 In a meta-analysis including 5,152 surgeon surveys among all specialties, 68% reported generalized pain, 71% felt fatigue, 37% reported numbness, and 45% reported stiffness.⁷ Sixty-one percent felt that operating exacerbated the pain, and 30% took their physical symptoms into account when recommending different approaches to surgery.⁷ Pain was commonly located in the back, neck, arms, and shoulders, but only 29% of respondents sought treatment for their symptoms.^7,8

Self-sacrifice is woven into the culture of surgery. The well-being and longevity of surgeons is commonly overlooked, and injuries are under-reported. In one study, only 20% of surgeons reported their injuries to their institutions.⁸ In this same study, there was a negative effect on productivity, with 22% of injured surgeons missing work and 35% performing fewer procedures during recovery.⁸ A meta-analysis of 5,800 surgeons and interventionalists reported a pooled prevalence of pain from 35% to 60%, with 12% of the surgeons requiring a leave of absence, practice modification, or early retirement.⁷ The physician workforce is anticipated to face a shortage by 2025.⁹ Although mitigating burnout has become a crucial effort, little attention has been given to prevention of work-related musculoskeletal disorders. The true scope of the economic burden of missed days and time off work for surgeons is also under-reported.⁸ Although we acknowledge that a certain degree of musculoskeletal disorders occur among aging adults, we cannot minimize opportunities for disability prevention that can have lasting effects on a surgeon's physical and mental health.

Box 1.

Surgical Ergonomic Recommendations to Prevent Work-Related Musculoskeletal Disorders

Box 2.

Web-Application Program for Stretching Every 20–40 Minutes While Remaining Sterile

• • Neck flexion and extension
• • Left and right neck rotation
• • Shoulder rotation and shrug
• • Lower back flexion and extension
• • Side bend to left and right, curling trunk
• • Upper back and hand stretch
• • Heal and foot lift
• • Gluteus squeeze

Data from Mayo Clinic. OR-stretch videos. Accessed August 13, 2022. https://www.mayo.edu/research/labs/human-factors-engineering/or-stretch/or-stretch-videos

Each route of surgery in gynecology (vaginal, traditional or robotic laparoscopic, and open approaches) has its own unique challenges and risks. In a survey of vaginal surgeons, the reported work-related musculoskeletal disorder prevalence was 87%, with pain focused in the neck, back, and lower extremities at least once a week.¹⁰ Among those who reported work-related musculoskeletal disorders, 14% missed work and 21% modified their work hours or surgical schedules.¹⁰ In another study, 8% had required surgery for back pain.¹¹ These authors posited that surgeons who performed most of their cases vaginally were more likely to require medication for a work-related musculoskeletal disorder compared with surgeons using other routes,¹¹ likely due to the unique nature of vaginal surgery, with its constrained work space. In one study in which ergonomists were able to objectively capture awkward postures, the assistant vaginal surgeon spent significantly longer time in trunk flexion and held static deviations of both the right and left shoulder (Fig. 1).¹² The most awkward posture for both primary and assistant vaginal surgeons was neck deviation, with 27% and 41% of the total time spent in this position, respectively (Appendix 1, available online at https://links.lww.com/AOG/D10).¹² In that study, pain was noted in the neck, bilateral wrists and hands, fingers, throughout the back, right upper leg, and bilateral feet.¹²

Fig. 1.: The primary surgeon during this vaginal surgery is hunched over with trunk lateral bend because the height of the table is inappropriately low. The assistant surgeon on the patient's right is bearing weight primarily on his back (right) leg, instead of equal weight bearing, and both assistant surgeons are engaged in excessive neck flexion and lateral torquing.

Surgeons can sit or stand to perform the surgery. When comparing these different positions, both standing and sitting can lead to pain in different muscle groups. The median percentage of time spent in an awkward trunk posture was lower with standing compared with sitting, but standing was associated with a higher percentage of awkward posture for the bilateral shoulders (Appendix 2, available online at https://links.lww.com/AOG/D10).¹³ Overall, surgeons reported more discomfort when standing.¹³

Regarding open surgery, there were 123,293 open hysterectomies performed in the United States in 2018.¹⁴ Most work-related musculoskeletal disorder data for open surgeries have been reported from other specialties. Unique conditions include foot pedals requiring surgeons to stand on one leg, accommodating cords from instruments, excessive height or width of tables leading surgeons to increase trunk flexion and shoulder elevation, and use of loupes or head-mounted lamps leading to neck flexion, strain, and risk for cervicospinal injury¹⁵ (Appendix 3, available online at https://links.lww.com/AOG/D10). A survey of gynecologists in Northern Ireland reported that 23.4% felt that abdominal surgery was a primary aggravating factor causing backache.¹¹

Today, more gynecologists are performing minimally invasive surgery (MIS) using traditional laparoscopy or robotic-assisted laparoscopy, with 339,281 MIS hysterectomies performed in 2018.¹⁴ This technology is associated with a unique set of work-related musculoskeletal disorders. In a survey of members of the European Association of Endoscopic Surgery, 72% of the respondents reported experiencing pain scores of 3 or higher on a 10-point scale during traditional laparoscopic cases, 48% during robotic-assisted laparoscopic cases, and 52% during gastrointestinal endoscopic cases, with pain in the back, neck, and shoulders over the previous 7 days.¹⁶ One systematic review found that surgeons performing MIS experience more pain in the neck, arm, shoulder, hands, and legs compared with those performing open surgery and that MIS is also associated with higher odds of fatigue and numbness.¹⁷

Some aspects unique to traditional laparoscopic surgery include static positioning of the head and trunk, table height to allow for use of long instruments, fulcrum effect by long instruments through fixed trocars, exaggerated arcing movements, poor instrument design, foot pedal use placing surgeons in awkward positions, and monitor placement¹⁵ (Appendices 4 and 5, available online at https://links.lww.com/AOG/D10). Electromyogram (EMG) studies have demonstrated increased thenar, forearm, and deltoid muscle use during traditional laparoscopic knot tying compared with open surgery.¹⁸

Another consideration during traditional laparoscopy is the effect of surgeon gender on muscle activation and instrument use. After controlling for surgeon's height and duration of surgery, female laparoscopists were found to have increased muscle activation on EMG for the upper trapezius, anterior deltoid flexor carpi radialis, and extensor digitorum.¹⁹ Many traditional laparoscopic instruments are designed for a one-size-fits all model, and several studies have demonstrated a relationship among smaller hand size, female surgeons, and more strain and discomfort associated with laparoscopic instrument use.¹⁹ A study evaluating gynecologic surgeons' gender and hand size showed that these factors were not associated with grip-strength decline during a fatiguing 3-minute trial of rapid repetitive use of three energy devices; however, surgeons with smaller hand size did experience greater ergonomic workload as measured by the NASA Raw Task Load Index scale.²⁰ Suboptimal handle design combined with excessive grip pressure can lead to compression of the digital nerve of the thumb, causing paresthesia and neuropraxia.¹⁵

Robotic-assisted laparoscopic surgery is considered to be associated with less pain compared with traditional laparoscopy. However, robotic surgeons may have unique work-related musculoskeletal disorders related to increased finger pain, eye strain, and pain in the hands and neck.²¹ In robotics, surgeons must be mindful of the proper chair position, allowing for neutral positions of the knees, forearm, head, neck, and back (Appendices 6 and 7, available online at https://links.lww.com/AOG/D10).¹⁵ When looking at workload using RULA (Rapid Upper Limb Assessment) or EMG studies, robotic-assisted laparoscopic surgery is associated with benefit to some muscle groups at the cost of increased workload in other muscle groups, such as the trapezius, thenar, and trunk region.¹⁵

As we turn our attention to the overall health of our surgeon workforce, we must also highlight physical well-being. Chronic pain can have a detrimental effect on mental and physical health. Currently, there is an unmet need for ergonomic education and disability prevention.⁷ Several studies have confirmed surgeons’ and interventionalists' lack of awareness of applied ergonomic recommendations.⁸ In one study 59–99% of physicians were unaware of ergonomic recommendations at their own institutions, and none had received mandatory ergonomic training.⁶

A wealth of literature has emerged to improve surgeons' ergonomics in the operating room. In general, neutral positions are encouraged while avoiding prolonged static positions, with a goal of keeping extremities as close to the body as possible. Patient positioning for optimal view and avoidance of awkward surgeon positions is important. For laparoscopy or open surgery, the upper arms should be perpendicular to the floor, with the elbows at an approximately 90° angle, the shoulders dropped, and the hands relaxed.¹⁵ Excessive flexion, extension, or abduction of the shoulders, forearms, elbows, and wrists should be avoided.¹⁵ Neck flexion should be about 20°. Table height should be adjusted for the tallest surgeon, with the height of the patient's abdomen (including with pneumoperitoneum for laparoscopic surgery) 70–80% of the surgeon's elbow height, with step stools for other team members. Feet should remain hip width apart, with weight evenly distributed. Knees should not be locked (Figs. 2 and 3). Cords should be removed from under the surgeon’s and the teams' feet, and foot pedals should be next to the surgeon's foot, in line with the target instrument and quadrant. Antifatigue mats can help with lower extremity discomfort.¹⁵ Support hose (TED stockings) can help with lower extremity edema (Box 1).

Fig. 2.: During open surgery, the surgeon's posture should be neutral, avoiding excessive forward or lateral tilt, keeping the elbow at 90°. Feet are maintained hip-width apart, with the knees not locked, and the weight evenly distributed. Foot pedals should be aligned with surgeon and the surgeon should use antifatigue mats. Reprinted with permission, Cleveland Clinic Foundation ©2022. All rights reserved.

Fig. 3.: During laparoscopic surgery, the surgeon should maintain neck flexion <25°, with shoulders slightly retroverted and abducted at 15–30°, and the elbows at a 90–120° angle. Reprinted with permission, Cleveland Clinic Foundation ©2022. All rights reserved.

For the robotic-assisted laparoscopic approach, the patient’s arms should be tucked at their sides to accommodate maximal surgeon maneuverability. Optimal port placement should avoid excessive horizontal or vertical instrument orientation. Monitors should be at or below eye level. Robotic-assisted laparoscopic surgery best practices include “ABC—always be clutching”—to continually adjust the surgeon's ergonomics to support the elbows on the armrest and maintain the biceps and forearm at a 90–120° angle, with the wrists slightly extended and fingers bent; minimal forehead pressure on the headrest to minimize posterior neck strain; use of a stool with back and lumbar support to avoid back flexion and lumbar disc strain; locking the wheels or using a rolled-up blanket behind the stool to maintain the proper surgeon ergonomic position and prevent pushing away from the console; and adjusting the stool height and the robotic foot platform toward the operator so that the elbows, hips, and knees are at a 90° angle.²² While sitting, excessive knee flexion should be avoided and the feet should be resting on the ground.¹⁵ (Fig. 4 and Box 1).

Fig. 4.: This robotic surgeon has minimal neck flexion, with elbows supported on the armrest, the wrists in slight extension, straight, the fingers bent, and the hips and legs at a 90° angle. The back is straight, and shoulders are relaxed, with the forehead only lightly touching the head rest, and the stool has back with lumbar support, in contrast to Appendices 6 and 7 (available online at https://links.lww.com/AOG/D10). Reprinted with permission, Cleveland Clinic Foundation ©2022. All rights reserved.

Recommendations for the vaginal approach include sitting during a vaginal case and adjusting the bed height to ensure that the primary surgeon is looking straight ahead without a head-bent or back-bent position to avoid excessive neck flexion, elevating the primary vaginal surgeon's feet using a stool for support while sitting, and assistants switching sides during the case (Box 1). Use of a headlamp can decrease awkward shoulder movements in light adjustments, although it may increase the biomechanical load on the neck (Fig. 5). ¹²

Fig. 5.: Recommendations for the vaginal approach include: sitting during a vaginal case and adjusting the bed height to assure the primary surgeon is looking straight ahead without a head-bent or back-bent position, avoiding excessive neck flexion; elevating the primary vaginal surgeon's feet using a stool for support while sitting; and assistants switching sides during the case. If standing adjust height to the primary surgeon to assuring neutral head position and then having assistants stand on stools. Using antifatigue mats when possible. Trunk should be in neutral position for all surgeons and shoulders dropped and elbows 90°.

Ergonomic education and intervention may help in prevention; an ergonomics curriculum implemented among robotic-assisted laparoscopic gynecologic oncology surgeons resulted in 88% changing their practice and an improvement in pain and discomfort by 74% of those reporting strain.²³ Exercise and experience (greater number of years in practice) are protective factors against work-related musculoskeletal disorders.

Just like sports, surgery requires the surgeon to use multiple muscle groups to complete a procedure. Stretching helps to prevent muscle strain and injury in sports. Using this principle, a group of investigators studied the use of microbreaks in the operating room and found benefit in pain scores, mental focus, and improvement in physical performance without compromising operating time.^24,25 These investigators then developed a web-application program identifying appropriate muscle stretches during timed intervals (Box 2).^26,27 Not only is stretching critical to preventing muscle strain during surgery, but strength training is equally important. In another study, plastic surgeons teamed up with physical therapists to identify common awkward postures and then developed strengthening exercises in an educational video.²⁸

The imperative to address a workforce facing decreased productivity, career compromise, and disability due to work-related musculoskeletal disorders should prompt funding for further study in mechanisms of injury and appropriate targets for interventions. Surgeons should partner with industry to innovate instrumentation to address gaps in ergonomic design. Future studies should characterize the associations of surgical approach or instrumentation with specific work-related musculoskeletal disorders (eg, conventional laparoscopy and cervical spine disease) and determine the efficacy of proposed environmental, equipment, and postural modifications. Given the high stakes of work-related musculoskeletal disorders, ergonomic training and awareness should be incorporated at all levels of the medical curriculum.

In 2020, the Society of Surgical Ergonomics was founded by a group of like-minded surgeons to create awareness and to study these critical issues. The American Board of Surgery has also created an ergonomic curriculum implemented during residency. Now is the time to create a similar curriculum in gynecology. Such curricula should include common awkward postures for each surgical approach that can lead to work-related musculoskeletal disorders, appropriate stretching before and during surgery, and muscle strengthening that can be performed outside of the operating room. We can help to ensure career longevity in surgeons by incorporating awareness of surgical ergonomics in addition to burnout, depression, and attrition among physicians.