Introduction

Ergonomics plays an important role in the work environment however it does not receive due attention. Many are unaware of the terminology much less the specifics it contributes to an efficient, safe, and productive workplace.

The term “ergonomics” is derived from the Greek words “ergon” meaning work and “nomos” meaning natural laws or arrangement. Ergonomics can be defined as the scientific study of people at work, in terms of equipment design, workplace layout, working environment, safety, productivity, and training. This depends on many factors including anatomy, physiology, psychology, and engineering. Simply, it can be said that ergonomics is the science of best suiting the worker to his workspace.

Ergonomics may also be referred to as the human factor in certain places. Considering that ergonomics involved in the operative room is vital for increasing efficiency and minimizing the fatigue of the surgical team. Ergonomics is essential in centers with high volume, where long continuous working time and repetitive actions are the norms.

Human errors have been classified in the following categories:

  1. (a)

    Mistakes: The surgeon makes an error because of an incorrect interpretation of the anatomy or situation, e.g., mistaking the CBD for the cystic duct and dividing it.

  2. (b)

    Slips: The surgeon makes the right decision but carries out the wrong action (e.g., presses the “cut” instead of the “coagulation” pedal on the electrocautery).

  3. (c)

    Lapses: The surgeon neglects to perform a procedure or a specific step in a procedure (e.g., forgets to check the integrity of a colonic anastomosis using air insufflation before closing).

There are various factors to consider in the OR during laparoscopic surgery which can ease the access and make working in such a setting productive and well-organized. Though they may seem insignificant initially however incorporating them into the daily workplace will reap benefits over time [1,2,3].

Straight Line Principle

The visual monitor from the surgery should be adjusted before the surgery to avoid undesirable postures or neck-straining for a prolonged time.

The monitor should be adjusted during the surgery if required depending on the surgical field to keep the visual plane in a straight line.

In the horizontal plane, the monitor should be straight ahead of the surgeon and in line with the surgical field along with the forearm–instrument motor axis. Additional monitors should be used if the assistants and nurses are standing in a different or opposite to the operating surgeon/operative field to avoid fatigue for the assistants (Fig. 1).

Fig. 1
An illustration of an exposed abdomen of a patient during an operation. One instrument is inserted in the navel, one is directly on the colon, while the other one is in another organ beside it. A straight line travels from the surgeon to the video monitor.

Straight line principle: the surgeon, the operative field, and the monitor should be in a straight line for maximum efficiency

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Triangulation

The placement of ports by surgeons is based on individual preference and experience. To facilitate easy instrument handling and to have a good visualization, trocars should be placed in a triangular manner. This is known as triangulation (Fig. 2). The target organ should be about 15 cm from the camera port. The remaining trocars are placed similarly in an arc at 5–7 cm on either side of the camera port. More ports can be placed in the same arc with a gap between instruments to prevent clashing. This allows the instruments to work freely at a 60–90° angle with no clashing and fighting with the other instruments (Fig. 3).

Fig. 2
An illustration of an exposed abdomen of a patient during an operation. An instrument is inserted in the navel, down to an organ. Two other instruments are also indicated beside, making a triangle formation.

Triangulation: This is important to avoid fighting and clashing of instruments and easy tiring

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Fig. 3
An illustration of an exposed abdomen of a patient during an operation. Three instruments are inserted inside. Two solid lines form the upper side of the diamond, while 2 broken lines form the lower side of the diamond. A horizontal broken line passes from one side to the other.

Baseball diamond concept

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When the endo-laparoscope is situated lateral to the working instruments, it is called “sectorization.” This makes it more challenging to work with all lateral ports as the vision is also lateralized, but with practice and use of an angled laparoscope, it can be adapted.

Manipulation Angle

The manipulation angle is the angle formed between two working instruments (active and assisting). The ideal manipulation angle is between 45–60° (Fig. 4); a smaller or larger angle is associated with increased maneuvering difficulty and poorer performance. A narrow angle will cause clashing and fighting between instruments, while a larger angle will result in the need to abduct the arms more leading to straining of the shoulder muscles.

Fig. 4
An illustration of an exposed abdomen of a patient during an operation. A see-through of organs. Two opposite circles from left and right form a V-shaped angle via broken lines. The angle is 60 degrees. These circles are connected to a bigger circle above them via broken lines.

Ideal manipulation angle

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Elevation Angle

The elevation angle is the angle between the instrument and the horizontal plane. There is a direct correlation between the manipulation and elevation angles. They should be equal to each other for maximum efficiency. For example, with a manipulation angle of 60°, the corresponding optimal elevation angle, which yields the shortest execution time and optimal performance is also 60° (Fig. 5).

Fig. 5
A side view illustration of an abdomen with 3 equipment inserted inside, forming a triangle formation. Instruments 1 and 2 are angled at a double-headed arrow labeled 2. Instruments 1 and 3 are angled at a double-headed arrow labeled 1. Instrument 3 is angled to an imaginary line at a double-headed arrow labeled 3.

Manipulation, Elevation, and Azimuth angle shown in a patient. 1. Manipulation angle, 2. Azimuth angle, 3. Elevation angle

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Azimuth Angle

The azimuth angle is the angle between the instrument and the optical axis of the endoscope. The ideal azimuth angle for easy and maximum productivity ranges from 30–45°.

Surgeons’ Body Posture

The ideal position for the laparoscopic surgeon is a relaxed stance with the arms slightly abducted, retroverted, and rotated inward at the shoulder level and the elbow should be bent at a 90–120° angle and the neck slightly flexed with a downward gaze. The operating table with clamps on the side for attachments can obstruct the surgeons/assistants from standing in the desired position. These should be organized so that they are at least obstructive position and removed if unnecessary.

Position of Visual Display (Monitor)

The position of the monitor depends on the size of the screen that is being used. However, ideally, the monitor should be 90–200 cm away in the straight line across from the surgeon in a gaze-down view. This is easier to attain by the use of ceiling booms which will help the movement of the monitor in forward/backward as well as up/down direction rather than on a trolley placed on the ground as then the height cannot be adjusted.

It is also beneficial to occasionally relax the body and mind by moving around, looking away from the monitor, and letting go of the instruments. In open surgery, the surgeon unconsciously takes these minibreaks but forgets during laparoscopic operations which are usually more intense with the surgeon/assistants in a more stationary position.

Gaze-Down View

The screen should be positioned lower than the surgeon’s eye level to avoid neck extension and straining. The most comfortable viewing direction is approximately 15° below the eye level to avoid the chin-up position. Viewing distance is dependent on the monitor size. It should be far enough to avoid straining on the eyes usually at 90–200 cm distance (Fig. 6).

Fig. 6
An illustration of a surgeon holding two instruments during laparoscopy. Two imaginary lines are viewed based on the eye level of the surgeon. In front of the surgeon are two monitors are placed.

Ideal surgeon stance, ideal monitor and table height during laparoscopy

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Height of Operating Surface (Table)

The operating table must be adapted to the surgeon’s height and position. The table’s height should be adjusted in such a way that laparoscopic instrument handles are slightly below the level of the surgeon’s elbows which should be flexed at a 90–120° angle. This is usually 0.8 times the elbow height of the surgeon.

Foot Pedal Location

Pedals should be placed near the surgeon’s foot and lined in the same direction as the instruments, toward the target quadrant and laparoscopic monitor. This allows surgeons to activate the pedal without twisting their body or the leg. Newer pedals with built-in footrest are preferable as it prevents the surgeon from keeping the foot hanging in the air.

Port Placement and Instruments

The ports should be placed such that the various instruments do not clash with each other. Also while the placement of the ports it should be noted that the ports should lie slightly obliquely pointed toward the target quadrant. This is of importance especially in obese patients to avoid working against the abdominal wall with a poorly inserted trocar.

Instruments should be inserted such that at least half of the instrument is inside the patient. If less than half of the instrument is inserted inside the abdominal wall then excessive motion at the shoulder will be required, which is likely to fatigue the surgeon sooner. After the instruments have been inserted into the ports they should be roughly at, or slightly below, the level of the surgeon’s elbows.

When it is necessary to continuously grasp tissues it is recommended to use an instrument that has a lock or ratchet mechanism that will maintain the force, also palming an instrument instead of using finger bows to hold it or using external fixators help in such conditions.

Surgeons and Team Placement

The surgeon can stand on either side or between the legs of the patient depending on the easy access, comfort, and preference to maintain a straight line principle. The assistant/nurse also should stand such that the view of the monitor is not obliquely placed or blocked by another. It is advisable to use multiple monitors to avoid visual obstruction, especially on ceiling booms to be height adjustable depending on the OR team.

Ambient Room Lighting

The OR should have the capacity to be dimmed during laparoscopic surgery to avoid glare and visual discomfort to the surgeon and the operating team. However, it should not be too dark for the assistants/scrub nurses/circulating nurses to pass instruments or hamper movement in the OR.

Scrubs and Footwear

The scrubs used should not be oversized or small to cause a restriction in the movement. The scrubs and the footwear should be light and well ventilated. The scrubs should not have too many pockets or items placed in them to drag down the scrubs to cause discomfort.

Technical Advancement and Clutter of Equipment

With the use of laparoscopy, there are extra instruments and equipment that are required, these take up valuable space hence a laparoscopic OR should be bigger. Also, since all the equipment are numerous and bulkier therefore they should be circulated using trolleys to avoid fatigue and musculoskeletal strain. The tubes and scopes should be organized on and off the operating table so that they do not cross and get tangled. Usually, each team has their method to achieve this and is usually perfected over time. Also, the assistant/nurse can help during the operation to maintain order. The Mayo’s trolley should be placed such that it avoids excessive turning and torsion of the scrubbed nurse/assistant while passing the instruments.

Conclusion

With the increasing use of technology in the field of laparoscopy, there are newer physical and mental challenges. This warrants more attention to promote better ergonomics in laparoscopy by encouraging the medical field to promote the principles of ergonomics and to conduct training using these ergonomic guidelines and also by promoting research in this field for a better understanding.

These matters though they seem minor and insignificant however, in the long run, they can lead to medical problems as well as decrease the efficiency of the surgeon/OR team and increase the operative time thus indirectly increasing OR cost, patient recovery time, and admission period.

The most common reason for the inability of ergonomics to be applied optimally is lack of awareness, communication gap, and lack of knowledge about associated medical problems. It is advised to have an active member/team who can communicate the properties and benefits of ergonomics to the rest of the OR for its implementation and smooth movement throughout the OR.