Enhancing ergonomics in robotic surgery—a review

Introduction

The field of ergonomics is composed of three main domains: physical, cognitive, and organisational. Physical ergonomics relates to the body’s response to physical and psychological stress. Cognitive ergonomics is concerned with mental processes and organisational ergonomics with systems optimisation. An advantage of robotic surgery (RS) is improved physical and cognitive ergonomics. The ergonomic advantages of improved visualisation, posture and manipulation may be partially offset by the disadvantages of loss of haptic feedback, fatigue from longer operating time, and impairment of situation awareness because of surgeon separation (1,2).

The ergonomic advantages of RS have been well described in many studies (3). The visualisation ergonomic advantages of RS include enhanced exposure, immersive three-dimensional view, camera control by the surgeon and screen location at line of sight (4). The postural advantages include ability to sit during surgery and to rest the forearms on the robotic console bar, as well as the freedom to move without concerns about maintaining sterility. Manipulation benefits are offered through the integrated technologies of miniaturised articulated instrument with seven degrees of freedom movement, elimination of the fulcrum effect, tremor filtration, magnification effect, and control of more instruments (5). Some of the ergonomic disadvantages of RS can be overcome with development of new technology, increasing experience, and better teamwork.

Most published studies on ergonomics and RS have been simulation based and have not investigated interventions which may enhance the known ergonomic advantages or overcome the ergonomic disadvantages. User well-being is an important outcome to consider when introducing new surgical techniques and equipment. Studies have reported increasing levels of occupational injury in surgeons and poor ergonomics for surgeons is a serious performance consideration that may shorten careers. Work-related musculoskeletal disorders are common in surgeons and any intervention which can improve ergonomics should result in less time off work, practice restriction or modification, and early retirement. This review will report on interventions during RS which can reduce visual fatigue, reduce musculoskeletal pain, enhance manipulation of robotic instruments (including avoidance of robotic arm clashes), offer haptic feedback, improve robotic skills to improve efficiency, improve cognition, and overcome workflow disruptions (Table 1).

Interventions to prevent visual fatigue

Visual fatigue can occur during RS because of eye strain related to prolonged viewing of the close video screen and/or accommodative stress related to three-dimensional vision (6). Simple non-invasive interventions can be used to reduce digital eye strain during RS. There is good evidence that improved neck posture with downgaze positioning (to reduce tear film evaporation), regular screen breaks (implementing the 20:20:20 rule of 20 seconds break every 20 minutes to view an object at 20 feet), eye relaxation exercises (to reduce the work of extraocular and ciliary muscles), refractive error correction (with physical or pharmacological interventions), lubricating eye drops use (such as artificial tears containing hyaluronic acid), and blink efficiency training to induce motor memory can reduce visual fatigue (6-9).

Interventions to reduce musculoskeletal pain

The postural benefits of RS can be enhanced by ergonomic training and positioning as well as taking advantage of freedom to have microbreaks with targeted stretching. The availability of the robotic console bar to rest the forearms and reduce weightbearing during surgery and ability to clutch the finger manipulators to maintain the upper limbs in ergonomic position can reduce sustained shoulder abduction and tension of the hand muscles. Optimal ergonomic positioning involves avoidance of shoulder abduction, resting of forearms on the console bar with the elbows at right angles, maintenance of a straight back, and resting of the feet comfortably on the ground with the knees at right angles (10). Adjustment of the robotic console settings by a trained ergonomists and implementation of ergonomic training sessions have been shown to reduce pain (10,11). Knowledge about intra-operative factors which may influence poor upper limb ergonomics and compensating for them during RS can help prevent post-procedure pain (12). Coaching of novice surgeons to use the clutch control more frequently has been shown to prevent prolonged abduction of the shoulders and core rotation (13).

Increasing RS experience is an independent factor for improved ergonomic positioning. A simulation study reported a significantly higher armrest load for experienced compared with novice surgeons (14). In one study, preference of subconscious ergonomic positioning of the hands over operating without visual perception mismatch (alignment of the hand position with instrument tip position which may require lifting the forearms off the console bar) was demonstrated for an experienced robotic surgeon (15). A systematic review of four studies found microbreaks, by interrupting periods of low-level intensity, with targeted stretching during surgery significantly reduced post-operative shoulder musculoskeletal pain (16).

Other interventions which may reduce forearm fatigue include forearm compression sleeves use and strengthening exercises (11,17,18). Forearm compression sleeves can be used during RS because there is no need to maintain sterility and has the potential to improve muscle recovery. Conditioning via resistance strengthening exercises, muscle stretching, proprioception training, and massage are interventions which have been shown to reduce delayed onset muscle soreness. One study found upper limb resistance exercises to be associated with less pain and fatigue in hospital workers (19). The seated position offers an ergonomic advantage for the surgeon to rest their lower limbs and to keep their back straight. Use of an ergonomic chair has been advocated. One study however found no clinically significant difference in shoulder muscle activity with use of ergonomic chairs utilising a backrest or smaller seating (20).

In summary, ergonomic training, positioning by an ergonomics specialist, coaching to encourage more frequent use of the clutch controller, more RS experience, microbreaks with targeted stretching, use of forearm compression sleeves, and resistance strengthening training are some interventions which can help reduce musculoskeletal pain during RS.

Interventions to improve manipulation

The manipulation benefits of RS can be enhanced by optimal port placement and other considerations. One study demonstrated spacing distance between ports, alignment orientation, and use of different ports for manipulation influenced manipulation angles during robotic colorectal surgery (21). The widest manipulation angles were achieved with the recommended oblique port spacing of 8 cm (rather than 6 cm) during dissection of the colon. Avoidance of clashes between the robotic arms and the bedside assistant arm is helpful to improve access for retraction, suction and other tasks. Avoidance of situations which can lead to clashing (such dissection at the most peripheral working field or of proximal structures), optimal placement of the assistant port, and use of a second assistant port are some techniques which can improve assistant access (22). Use of the patient clearance buttons can drop the posterior elbows of the robot arms to allow more spacing between them without changing the instrument tips position inside the abdomen, thereby preventing external clashes (23).

Haptic feedback

A major disadvantage of RS is loss of force and tactile feedback. Elimination of haptic feedback can lead to inaccurate force application. The availability of three-dimensional vision can partially compensate for lack of haptic feedback via degree of tissue deformation recognition. Increasing RS experience has been associated with better tissue assessment without haptic feedback (24). In simulation studies, addition of haptic feedback resulted in reduced grasping forces, improve consistency, and improved precision (25,26). In addition, multi-modal feedback systems which allow for tactile, kinaesthetic and vibrotactile feedback has been shown to reduce force by almost 50% when compared with single modality feedback alone (27). A meta-analysis of 55 studies confirmed positive effects with regards to applied force, completion time and accuracy with the assistance of haptic feedback (28). The effect size with haptic feedback from virtual boundaries, with the creation of a safe operating zone, was similar to that with force feedback (28). Like other robotic systems such as Senhance, the new Intuitive da Vinci 5 surgical system will offer force feedback via sensors near the instrument tips. Future studies will reveal the ergonomic impact and clinical benefits of the addition of haptic feedback.

Interventions to improve robotic skills and reduce operating time

Apart from increasing real life RS experience, there are other interventions which can help improve robotic skills and reduce operating time. Robotic surgical simulator training, coaching/proctoring, and video review are some methods which can enhance robotic skills and shorten the learning curve (29-32). Video review by experienced and novice surgeons has been used to increase efficiency, improve technical skills, and for reflection (32). There are other factors which impact RS console time and they include use of hybrid technique (with laparoscopic mobilisation of the colon and robotic dissection of the rectum), previous surgical experience, use of a dedicated operating room team, and gradual introduction of complex cases (33).

Cognitive training

The relationship between cognition and RS is complex because the physical ergonomic benefits may be offset by the organisational ergonomic detriments related to team separation (34). Cognitive training can improve skills during the cognitive to integrative and then autonomous stages of motor learning (35,36). These skills include attention, memory and problem solving. Automation of constructed schemas can occur with repetition to free up working memory. The techniques of cognitive training include mentorship, cognitive simulation training, mental training and rehearsals, and cognitive task analysis (CTA). The dual console robotic system offers the opportunity of real-time assessment and constructive feedback by an expert mentor (37). Mentoring during real or simulation RS has been shown to reduce mental workload by developing not only motor skills but also cognitive skills (38). Initial mental rehearsal of a physical task without execution has been shown to be an effective intervention to improve technical RS skills (39). A meta-analysis found CTA based training, which involves expert review and analysis of the cognitive processes underpinning each key operation step, to be significantly more effective in improving technical performance than with conventional training (40). The benefit was attributed to the structured framework provided by CTA training, incorporating task sequency, important decision points and rationale, technical tips for key steps, and strategies to avoid and manage potential pitfalls.

Overcoming workflow disruptions

Surgeon separation and reduced situation awareness are the main contributor of workflow disruptions during RS (41). A review article reported a significant gap between identification of workflow issues and implementation of solutions in RS (42). Many articles recommended an intervention based on their study findings but did not evaluate outcomes of an intervention. The possible organisational interventions include team and role-specific training, adjustments to the operating room layout with better spatial configuration, use of checklist to improve coordination, enhancement of teamwork and collaborative team situation awareness, communication improvement (such as use of read-back, loop closure, and noise-cancelling headsets), and team briefing.

Support for resilience, which is an important adaptive response to unexpected events, can help overcome workflow disruptions to maintain reliable performance (43). Resilience supports can be categorised as person related (such as skills training, personality, anticipatory planning, communication, and leadership), task-related (such as ergonomics), tools and technology related (such as availability, usability, and effective functionality), organisation related (such as safety culture, team responsibilities, and education), and environment related (such as spatial requirements, setup, walking paths and ambient conditions) (44).

Conclusions

The review article has reported on interventions which can enhance the ergonomic benefits and overcome the ergonomic deficiencies of RS. Previous research on ergonomics and RS mainly reported on the physical ergonomic benefits and the organisational ergonomic detriments. Most studies were simulation based and the subjects were usually novice surgeons such as junior doctors and medical students. Therefore, the results may not be generalisable to real-life surgery and surgeons. There is a paucity of studies reporting on interventions which can further improve the ergonomics of RS. The exception are studies which have reported on interventions which enhance robotic skills. Some of the interventional studies involved surgeons performing open or laparoscopic surgery, office workers, or athletes. Most studies on interventions to reduce visual fatigue involved research on participants who used computer screens regularly. The studies investigating interventions to reduce musculoskeletal pain involved surgeons performing open surgery and sportspeople. Introduction of haptic feedback in the newer versions of the robotic console system may allow more research in real-life situations, with the results not based on simulation studies. Research into workplace disruptions have been reported frequently but most of these studies have not reported on interventions to overcome the difficulties. Some of the results of this review have been extrapolated from research not involving RS. There is potential for more direct RS research on interventions (such as the effects of screen breaks on visual fatigue) and further research on how ergonomic interventions can impact surgeon welfare and patient outcome. The clinical implications for the patient are more precise surgery and better surgical outcomes because the operating robotic surgeon is healthier and more comfortable.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, AME Surgical Journal for the series “Robotic Colorectal Surgery”. The article has undergone external peer review.

Peer Review File: Available at https://asj.amegroups.com/article/view/10.21037/asj-24-43/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://asj.amegroups.com/article/view/10.21037/asj-24-43/coif). The series “Robotic Colorectal Surgery” was commissioned by the editorial office without any funding or sponsorship. Z.H.A. served as the unpaid Guest Editor of the series and serves as an unpaid editorial board member of AME Surgical Journal from October 2024 to December 2026. The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This article does not contain any studies with human or animal subjects performed by any of the authors.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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