Prevention and rehabilitation of musculoskeletal pain among abdominal and pelvic surgeons with intelligent physical exercise training (IPET) and intraoperative ergonomic recommendations (ERGO): study protocol for a multicenter open-label randomized controlled trial in Denmark and North America (USA)

Abstract

Background

Surgeons are in high demand due to the ageing population’s increased need for surgery. However, the high prevalence of musculoskeletal pain (MSP) threatens their career longevity. While improving intraoperative ergonomics is crucial, physical exercise training is also widely used in managing MSP. The objective is to investigate the added effectiveness of intelligent physical exercise training (IPET) when combined with intraoperative ergonomic recommendations (ERGO), compared to ERGO alone, in reducing MSP among abdominal and pelvic surgeons.

Methods

This pragmatic, multicenter, 20-week, superiority, open-label randomized controlled trial (RCT) is conducted in two phases. Phase 1 is a 3-month ergonomic educational period (ERGO) delivered to all participants. Phase 2 is the RCT, where participants are randomized 1:1 to ERGO (control) or ERGO + IPET (intervention). ERGO provides recommendations for operating room (OR) ergonomics, including posture and microbreaks, displayed in and around ORs. IPET prescribes 50 min of individualized weekly exercise, tailored to MSP, job profile (sedentary, walking/standing, or heavy work), physical capacity, and health risk indicators, and is delivered via a mobile application. Eligible surgeons specialize in gynecology, urology, and colorectal surgery and perform ≥ 4 h/week of abdominal or pelvic surgery (robot-assisted, laparoscopic, or open, excluding vaginal surgery), and complete the Phase 1 questionnaire. Surgeons advised against exercise by their GP are excluded. Participants are recruited from regional and academic hospitals in Denmark and North America. Enrollment begins with completion of the ERGO survey and consent in the baseline questionnaire. Recruitment started 13 December 2023, with a target sample size of 83. The primary effect of interest is the between-group difference in MSP intensity (0–10 numeric rating scale) at 20 weeks in the body part reported as most painful at baseline, analyzed using a linear mixed model with baseline MSP as covariate. Harms include increases in MSP or injury, though these will not be systematically collected. Participants and research staff are not blinded. Outcome interpretation will be blinded to group allocation.

Discussion

This trial addresses a gap in strategies to mitigate MSP among surgeons by combining ergonomics recommendations with app-delivered IPET. Findings may inform strategies to improve surgeon well-being and reduce future workforce shortages.

Trial registration

Clinicaltrials.gov, NCT06112106. Registered on October 4, 2023.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-025-09178-x.

Background

Surgeons are highly specialized healthcare professionals who undergo many years of extensive training. Given the rising demand for both the number and complexity of surgeries due to an aging population and an increase in cancer-related procedures, there is a societal imperative that they remain healthy and fit for work throughout their careers [1]. However, musculoskeletal pain (MSP) is highly prevalent: a 2022 meta-analysis among gynecologists and global survey among urologists reported MSP prevalences of 82% and 81%, respectively [2, 3], with more recent data indicating no substantial change among gynecologist [4]. Similarly, a multi-specialty international survey from 2023 among laparoscopic surgeons reported a 90% pain prevalence [5], consistent with a 2019 survey among surgeons in the same specialties included in the present protocol [6, 7]. In that study, most participants reported multisite pain (two or more painful body sites), with the highest pain intensities reported in the neck, lower back, upper back, and shoulders [6, 7]. Multi-site pain has been shown to negatively affect work (21%), leisure time activities (40%), and sleep (27%) [7], and in up to 12% of surgeons it may lead to practice restrictions or early retirement [2, 8].

Working postures that involve awkward, static, and repetitive movements with high precision demands are common for surgeons and are well-known risk factors for MSP [9, 10]. The existing literature calls for better ergonomics in the operating room (OR) to mitigate what has been called “the impending epidemic” of surgeon MSP [8, 11]. Although ergonomic principles and practices have been on the agenda for decades, awareness and adoption of these practices among surgeons remain limited [11–14]. In a small study among general surgery residents, all residents reported little to no ergonomics knowledge with 68% reporting that ergonomics was rarely discussed in the operating room (OR) [15]. In a survey among US medical schools, 98% reported their students will receive less than 3 h of ergonomic education [16], which is supported by a survey among directors of surgical and interventional medical specialties in the USA where 1.5% provided formal surgical ergonomics education (SEE) and 25.4% provided informal SEE [17].

Studies indicate that greater understanding of surgical ergonomics is associated with a higher degree of application in practice, with up to 93.3% of those who are aware of ergonomic information reporting its application [11, 18]. Thus, sound ergonomic knowledge should be an integral part of any job, including performing surgery. Nevertheless, solely focusing on the surgical ergonomics in the OR, i.e., the external work demands created by the physical surroundings, may only be part of the solution and the evidence on its effects on surgeons’ musculoskeletal health is limited [19]. In contrast, the evidence on the benefits of physical exercise training in rehabilitation and prevention of MSP is well-supported [20–22]. Maintaining overall fitness and muscle strength appears to be protective against MSP when pursuing a career in surgery, as 66% of surgeons who exercise regularly (≥ 4 times per week) reported no pain, compared to 34% of those exercising less. Similarly, greater handgrip strength was protective, with MSP prevalence of 79% among surgeons with above-average strength versus 93% among those with below-average strength [6, 23].

Tailored preventive and rehabilitative physical exercise training may be even more beneficial than solely optimizing surgical ergonomics and engaging in general exercise [21]. Thus, intelligent physical exercise training (IPET) was designed to be tailored according to the individual’s occupational exposure, health status, physical capacity, and MSP [24]. The IPET program has demonstrated positive effects on workers’ health and MSP in various occupational groups with high physical work demands [22]. However, its effects on MSP rehabilitation and prevention among surgeons remain unknown.

Objective

The objective is to investigate the added effectiveness of individualized physical exercise training (IPET) when combined with intraoperative ergonomic recommendations (ERGO), compared to ERGO alone, in reducing MSP among abdominal and pelvic surgeons. Our hypothesis is that ERGO alone (control group) may prevent or lead to a slight, but not clinically relevant, reduction in MSP, and that the combination of IPET + ERGO (intervention group) will have a synergistic and clinically relevant effect, resulting in a greater reduction in MSP compared to ERGO alone.

Methods: population, interventions, outcomes

Trial design

This protocol follows the Standard Protocol Items: Recommendations for Interventional Trials guidance for reporting protocols for clinical trials (SPIRIT) [25] and adheres to the Template for Intervention Description and Replication (TIDieR) checklist [26]. The trial was registered prospectively at Clinicaltrials.gov (NCT06112106), which meets the WHO Trial Registration Data Set standards, and will adhere to the declaration of Helsinki. The trial protocol and statistical analysis plan (SAP) will be available at ClinicalTrials.gov (NCT06112106).

The trial is designed as a multicenter, superiority, open-label block-randomized controlled trial (RCT) with two parallel arms allocated in a 1:1 ratio, with a 20-week intervention period with baseline, 12-, and 20-week outcome assessments (Fig. 1). Two surgeons, representing the target study population, contributed to the trial design, trial conduct, and participated in the reporting of results.

Fig. 1.

Pre-trial and trial time-line with assessment time points

Participants are recruited from hospital departments specializing in gynecology, urology, and colorectal surgery at selected Danish and North American academic medical centers. Detailed site information is available on Clinicaltrials.gov. Recruitment and baseline assessments commenced in December 2023 and is expected to run until March 2026 or until the required sample size is attained. Figure 2 illustrates the flow of participants.

Fig. 2.

Flow of participants from the pre-trial phase through to the end of the trial

Population

Eligible persons are primary and assisting surgeons from gynecology, urology, and colorectal surgery, who perform a minimum average of 4 h per week of robot-assisted laparoscopy (RAS), laparoscopy (LAP), or open surgery (OPEN) in the abdomen or pelvis (excluding vaginal surgery), and who complete the Phase 1 follow-up questionnaire. Surgeons whose general practitioner advises against performing physical exercise training are ineligible to participate in the trial.

The intervention

The intervention consists of two phases: a pre-trial educational phase (Phase 1) and the trial phase (Phase 2) (Figs. 1 and 2).

Phase 1: pre-trial education on good ergonomics

The first phase begins 12 weeks before the trial and is initiated with a presentation on Good Ergonomics (ERGO)—recommendations on surgical ergonomics—delivered by a member of the research team. The goal is to establish a basic understanding of surgical ergonomics and its underlying rationale, forming the basis for the “standard condition,” and to create awareness of the project.

ERGO has two overall elements: recommendations on (1) improving work postures in the OR, i.e., adjusting monitor height, adjusting the robotic console to maintain a neutral position of the joints, and (2) performing intraoperative microbreaks with stretching exercises.

ERGO was informed by a systematic literature review with the aim to elucidate the effects of ergonomic practices within the OR on surgeons’ musculoskeletal health and workload (PROSPERO registration no. CRD42022354609; findings will be published separately), a review of surgical ergonomics [27], and general best-practice ergonomic guidelines from the Danish Working Environment Authority.

Improved surgical ergonomics would benefit participants by reducing physical demands during surgery, such as static, awkward, and constrained postures, which are known risk factors for developing MSP [10]. Figure 3A illustrates an ERGO poster with recommendations for LAP surgeons on maximal abduction of shoulders, optimizing the height of the table, placement of the monitor, and the angle between the instruments. Additionally, two similar posters provide surgeons with ergonomic recommendations during OPEN and RAS (Additional Figs. 3B and C).

Fig. 3.

Good Ergonomics posters. A Laparoscopic surgery B Open surgery C Robot-assisted surgery [27]

The ERGO posters will be displayed in or near the OR, in OR break rooms, in the OR-Stretch web-app, in locker rooms, and in respective departments, with local variations. The posters include a QR code linking to short videos that explain the importance of OR ergonomics and microbreaks in preventing MSP. Additionally, during the initial three weeks, support for introducing ERGO was available approximately twice per week at some participating departments.

The second ERGO element is the recommendation to perform regular (at least every 60 min) intraoperative microbreaks with stretching exercises. Often, surgeons have limited ability to take a break at their discretion and may overlook early signs of fatigue. To address this, microbreaks are short structured intraoperative breaks with guided dynamic stretching exercises targeting the upper body and trunk to lower discomfort and fatigue, stress, and maintain focus [28–30].

The microbreaks are guided either by Mayo Clinic’s OR Stretch web app [31, 32], or by a locally adapted Danish-language audio version, accessible via a QR code. The microbreak lasts approx. 90 s. At the beginning of a surgical day, the OR team is encouraged to agree on the planned frequency of microbreaks for that day’s surgeries, e.g., at 60-min intervals or at a surgically convenient time. For surgeries expected to last less than 60 min, it is suggested to perform the microbreak immediately post-surgery. Figure 4 illustrates the microbreak poster with illustrated stretching exercises and instructions that can either be read aloud by the OR nurses or listened to via audio by scanning the QR code (note: QR code not shown). The OR-stretch web-app can be accessed here: https://orstretch.mayoclinic.org/.

Fig. 4.

Poster illustrating the stretching exercises to perform during a microbreak [28, 31, 32]

Phase 2: randomized controlled trial (IPET + ERGO vs. ERGO)

The second phase is the 20-week trial period. Again, this phase is initiated with a presentation by a member of the research team introducing the RCT, the IPET concept, eligibility, and details on how to participate. Additionally, promotional materials such as informational handouts or other department-specific items may be used to raise awareness and encourage participation in the trial.

The groups

All participants will be encouraged to continue to practice the ERGO principles in their OR practice throughout the trial period. This is considered “standard condition” and represents the control group. In the intervention group, ERGO is combined with IPET, a physical exercise training concept with tailored evidence-based exercises that should be performed for a total of 50 min per week, either alone or with other intervention-group colleagues. IPET considers individual occupational exposure (e.g., sedentary, walking/standing/or heavy work), health status, physical capacity in terms of fitness, strength, and balance, as well as MSP prevalence and intensity. The theory behind IPET is that physical exercise training has a pain-relieving effect, with aerobic exercise providing acute benefits and strength training offering long-term effects [24, 33]. Further, as a result of improved muscular strength and endurance, the relative load during work is reduced, leading to less strain and less accumulated fatigue during surgery. Ultimately, this should result in a decrease in MSP [33]. The weekly 50 min IPET can be performed in one session or divided into 2–5 shorter sessions with the same effect [34].

Intelligent physical exercise training

Originally, intelligent physical exercise training (IPET) was prescribed based on physiological measurements that determined the training categories (aerobic, strength, or functional training) [24]. Over decades of research, the IPET concept evolved into a mobile application, the Intelligent Motion app (hereafter referred to as “the app”) which serves as the main component of the intervention in this trial. The app was pilot-tested among different populations, including health workers, and university employees. The self-assessed measurements and their cut-points leading to IPET exercise prescription are described in Table 1 (modified from [35], under the terms of the Creative Commons Attribution License). Each intervention group participant will receive access to their individualized IPET program through the app. Download instructions and a unique access code will be sent via e-mail to ensure that the app cannot be accessed or shared by other trial participants.

Table 1.

Cut-points leading to prescription of IPET in the Intelligent Motion app

	Variable	Measurement	Description Model	Cut-point/Group allocation
Job profile	Occupational exposure category	Self-report	How would you categorize the physical demands in your main job? (1) Mainly sedentary work that does not require physical exertion (2) Work largely performed while standing or walking (3) Standing or walking work with some lifting and/or carrying activities (4) Heavy or fast-paced work, which is strenuous	1. Sedentary: moderate to high intensity aerobic training 2. Standing/walking: high intensity interval aerobic training + function training 3. + 4. Physically heavy: whole body muscle endurance training
Physical capacity profile	Cardiovascular fitness	Self-report	How would you score your aerobic capacity compared to others of your own age and sex? Assessed on a 0–10 numerical rating scale (NRS) ranging from as poor to as good as possible	Responses below 5 (corresponding to average) lead to prescription of extra aerobic training
	Muscle strength	Self-report	How would you score your strength capacity compared to others of your own age and sex? Assessed on a 0–10 NRS ranging from as weak to as strong as possible	Responses below 5 (corresponding to average) lead to prescription of extra all-round strength training
	Balance and function	Self-assessment	Self-assessed standing time on non-dominant leg with the arms crossed over the chest (hands on the shoulders). Three trials are given	If the individual loses balance before reaching 30 s, functional training is prescribed
Health profile	Body mass index	Self-assessed or self-report	Assessed as an individual’s weight in kilograms divided by the square of height in meters	A body mass index above 25 leads to the prescription of extra aerobic training
	Musculoskeletal disorders	Self-report	For how many days in total have you had (specific body part) pain during the last 3 months/7 days? If symptoms have been prevalent for one or more days, a follow up question is asked about average pain intensity: Please indicate your level of (specific body part) pain (0–10 NRS) within the last 3 months/7 days	Any symptoms lead to prescription-specific strength training for the body part. If an individual has symptoms in more than two (tree) body parts, the pain intensity guides the prioritization

NRS numerical rating scale.

The text in italics represents the questions being asked in the app to design the IPET program.

Each participant’s 50-min IPET program will have 20 min of aerobic exercise training allocated to target their physical work demands. Depending on their profile, such as sedentary work, walking/standing, or physically heavy, the aerobic component prescribed will consist of moderate- to high-intensity aerobic training (14–15 on the Borg 6–20 scale [36], which corresponds to 77–95% of VO_2max [37]), high-intensity interval aerobic training (17–19 on the Borg 6–20 scale (> 96% of VO_2max) with rest breaks maintained at an intensity of 8–0 (< 60% VO_2max)) with functional training, or overall muscle endurance training, respectively.

The remaining 30 min will consist of a combination of aerobic-, strength- and functional training depending on individual profile [24]. Additional aerobic-or functional training can be prescribed based on physical activity profile. Any MSP will lead to the prescription of strength training for the affected body part. All participants will start with two sets of 15 repetitions, with the number of repetitions decreasing as the load is increased. See Table 2 for the strength training progression scheme.

Table 2.

IPET strength training progression scheme. RM repetition maximum

Week	No. of sets per exercise	No. of repetitions (RM load)
1	2	15
2	2	15
3	3	15
4	2	12
5	3	12
6	4	12
7	2	10
8	3	10
9	4	10
10	2	8
11	3	8
12	4	8
13	4	8
14	2	8
15	3	8
16	4	8
17	4	8
18	4	8
19	4	8
20	4	8

The training load will be adjusted using elastic resistance bands (Theraband). Participants will receive a set of four elastic bands with varying levels of tension/resistance from “very easy” to “hard” (red, green, blue and black). Guidance on selecting the appropriate elastic band and on progression/regression is available in the app, along with access to an IPET knowledge bank (Fig. 5A). Figure 5B illustrates an example of an IPET program. Training progression and competition with colleagues can be tracked in the app by creating teams and inviting colleagues to join a training community via a shared code (Fig. 5C). Only colleagues in the intervention group have access to the app and can use the code. No personal health data will be shared within the app beyond team membership and exercise progress.

Fig. 5.

App screenshots. A App knowledge bank. B Screen shot with an example of an IPET program. C Training community

Participants are encouraged to complete the exercises in their leisure time or, if possible, during working hours [24, 38–40]. The app will track user interactions, including completed training minutes per week, the frequency of app usage, and the content accessed.

Outcomes

The primary effect of interest is the between-group difference in worst MSP intensity at 20 weeks, assessed using a 11-point numerical rating scale (NRS) for the body part with the highest reported pain intensity at baseline. In cases where multiple body parts have equal pain intensity, the body part with the longest duration of pain will be selected. If both pain intensity and pain duration are equal across painful body parts, the body part baseline NRS score will be selected according to the most prevalent painful body part among Danish surgeons [7]. All outcomes are self-reported and validated questionnaires will be used where possible.

The secondary outcomes include pain case status, MSP last 7 days, MSP duration, MSP consequences, general health, burnout, and workability (Table 3). The following descriptive variables will also be collected: working conditions, use of pain medication, physical activity profile, physical resources, time spent on physical activity, and compliance with ERGO. At 20-week follow-up, participants in the intervention group will be asked to rate the app overall, its usability, and their likelihood of recommending it.

Table 3.

Summary of data collection variables and time points

	Scale/categories	Data collection instrument (unit)	Assessment time point
			Baseline	12 weeks	20 weeks
Primary outcome
Pain intensity (3 months) Median/mean [SD/IRQ]	11-point ordinal NRS scale (0 = no pain, 10 = most intense pain) the past three months in; neck, shoulders, elbows/arms, wrists/hands, upper back, lower back, hips, knees, ankle/feet	The Nordic Musculoskeletal Questionnaire (modified) [41]*	x	x	x
Secondary outcomes
Pain case status Proportion	Pain case (NRS ≥ 3) Non-Pain case (NRS < 3)	Self-constructed categories
Days with musculoskeletal pain (past 3 months) Proportion	0 days 1–7 days 8–30 days More than 30 days but not every day Every day	The Nordic Musculoskeletal Questionnaire (modified) [41]*	x	x	x
Pain intensity (7 days) Proportion	11-point ordinal NRS scale (0 = no pain, 10 = most intense pain) the last 7 days in; neck, shoulders, elbows/arms, wrists/hands, upper back, lower back, hips, knees, ankle/feet	The Nordic Musculoskeletal Questionnaire (modified) [41]*	x	x	x
Days with leisure or work affected by pain Proportion	0 days 1–7 days 8–30 days More than 30 days but not every day Every day	The Nordic Musculoskeletal Questionnaire (modified) [41]*	x	x	x
Use of pain medication Proportion	Daily  ≥ 1 time/week  ≥ 1 time/month Rarely/never	Self-constructed questions	x	x	x
General health Median/mean [SD/IRQ]	Scored 0 to 100 points with higher scores indicating a better health status	12-item short form (SF-12) [42]	x	x	x
Personal and work-related burnout Proportion	Scores range from 0 to 100, where < 50 indicates no/low burnout, 50–74 moderate burnout, 75–99 high burnout, and 100 severe burnout	Copenhagen Burnout Inventory (modified) [43, 44]¤	x	x	x
Work ability Median/mean [SD/IRQ]	Scores range from 7 to 49 with higher scores indicating better work ability	Work Ability Index (modified) [45, 46]b	x	x	x
Descriptive variables
Moderate to vigorous physical activity Proportion	Less than 30 min 30–89 min 90–149 min 150–299 min 300 min or more	Self-constructed questions inspired by the WHO physical activity recommendations [47]	x	x	x
Physical activity level during leisure time Proportion	Physically inactive Some light physical activity Regular physical activity and training Regular hard physical training for competitive sports	Saltin-Grimby Physical Activity Level Scale [48]	x
Physical resources compared to peers Median/mean [SD/IRQ]	Aerobic fitness, strength, balance 11-point ordinal NRS scale from 0 to 10 (0 = weak/poor, 10 = strong/good)	Strøyer self-reported physical resources scale (modified) [49]a	x	x	x
Working conditions Median/mean [SD/IRQ] Proportion	Surgical specialty (colorectal, gynecology, urology, other) Weekly working hours as primary and assisting surgeon	Self-constructed questions	x
Compliance with ERGO recommendations Proportion	Never Rarely Sometimes Most of the time Always Don’t know	Self-constructed questions		x	x
Compliance with IPET Median/mean [SD/IRQ]	No. of IPET minutes performed per week (average)	Self-constructed questions			x**
Rating of the IPET app Proportion	An overall rating of the app, usability, and likelihood of recommending it will be rated from 1 to 5 with a higher score indicating a better rating	Self-constructed questions			x**

All outcomes will be assessed at baseline, 12 and 20 weeks after intervention start. *A modified version of the Nordic Musculoskeletal Questionnaire about the locomotive organs [41] will be used with the 12-month prevalence replaced by a 3-month prevalence, and in case of any prevalence, the intensity of the musculoskeletal trouble will be assessed by an 11-point NRS scale (0 = no pain, 10 = most intense pain). ** Intervention-group only.

^aStrøyer’s self-assessed physical fitness scale will be used in a modified version with two of five domains of fitness excluded (endurance and flexibility) [49]

¤A modified version of The Copenhagen Burnout Inventory will be used with one of three domains excluded (clinician burnout) [43]

^bThe Work Ability Index will be modified by collapsing the list of 14 diseases in item no. 3, into five categories (problems due to an earlier accident, musculoskeletal disease, cardiovascular disease, respiratory disease, and depression or other mental illness) [50]

The Saltin Grimsby physical activity level scale [48], and the SF-12 [42] will be used with no modifications.

Participants may experience mild, short-term muscle soreness immediately after a session and for up to 72 h. This is common and a harmless and expected response to exercise. Although increases in musculoskeletal pain (MSP) or injury are also considered harms, such events have been rare in previous studies of similar interventions, with no serious side effects reported [20]. As these outcomes are not anticipated, they will not be systematically recorded.

Sample size

The prevalence of MSP among surgeons is reported to be around 90% [6, 7], with many experiencing multisite pain and a pain intensity of 3 to 4 on a 11-point NRS. An MSP intensity ≥ 3 NRS points is considered the threshold for clinically important pain [51], and defines a pain case in this trial. A pain reduction of 30–40% (corresponding to approx. 1.5 NRS points) is considered the minimum clinically important difference (MCID) [52], and this level of improvement has been demonstrated in comparable trials investigating IPET [53–55]. Therefore, the targeted MSP reduction is a between-group difference of 1.5 NRS points [52].

To detect this difference in MSP intensity between the intervention and control groups, a two-sided independent sample t test was used for the sample size calculation. With a standard deviation of 2.0 NRS points, a power of 80%, and a significance level (alpha) of 0.05; 58 participants in total are required. To account for a drop-out rate of up to 30%, the total sample size is 83 participants. The sample size calculation was performed using Stata (version 17).

Methods: assignment of interventions

Sequence generation and allocation concealment mechanism

Participants will be randomly allocated to either the control or intervention group with a 1:1 allocation ratio. The randomization will follow a computer-generated sequence with permuted and random block sizes of 4, 6 and 8 [56], stratified by pain case status. The allocation sequence list will be prepared prior to study start by a central REDCap data manager who is not involved in the trial. A member of the research group will initiate randomization by clicking a “randomize” button in the REDCap system, which will then automatically allocate participants to a group. Participants will receive automated e-mails informing them of their group status (e.g., “Congratulations, you have been enrolled in the intervention group”) along with guidance on how to download the app. The control group participants will receive a message that encourages them to continue with ERGO for the next 20 weeks and that they will be offered IPET after the trial ends.

Due to the nature of the intervention, neither the participants nor members of the research team will be blinded to group assignments.

Methods: data collection, data management, and analysis

Data collection

Data will be entered directly into REDCap by participants (survey responses), and REDCap automatically performs range checks, branching logic, and validation rules to minimize entry errors. Each participant is assigned a unique study ID to ensure de-identification. Data will be collected at four time points (Fig. 1). The first data collection occurs at the end of Phase 1, where surgeons will be asked about their awareness of the ERGO recommendations and the extent to which they have applied it in the OR. The questionnaire will also address topics such as the presence, location, and duration of MSP experienced while operating in the past three months. Further topics include awareness of and adherence to ERGO, actions taken to reduce discomfort while operating, surgical modalities used in the past three months, and whether MSP influences the selection of surgical modality. After completing the Phase 1 follow-up questionnaire, participants are invited to complete the Phase 2 RCT baseline questionnaire during which electronic informed consent to participation and data handling is obtained. Thus, only those who complete the Phase 1 follow-up questionnaire can participate in the trial. The baseline questionnaire constitutes the second data collection point. The third and fourth data collection points occur at 12 and 20 weeks after baseline. The data collection instruments can be found in the supplementary material.

Data management

Data from the online questionnaires is stored on a secure REDCap database with access limited to key research group personnel. Participants’ name and personal identification numbers will not be collected.

During the trial, data from the IPET app will be collected and stored securely by the app developer, 50 Minutes Aps, using Amazon Web Services storage facility in Germany. All data collected will be de-identified before processing, and results will be reported in aggregate at the group level. Data handling complies with Danish and American legislation on the protection of personal data. Primary research data and related materials will be securely stored at Aarhus University for at least 5 years following project completion, in accordance with university policy. Personal data will only be retained as long as necessary for the research purpose, after which it will be either anonymized, securely archived, or deleted. A detailed Data Management Plan describing procedures for coding, quality control, and security is available from the corresponding author upon reasonable request.

Data access

Access to the final trial dataset will be restricted to the study investigators at Aarhus University and collaborating institutions. In accordance with Aarhus University’s data protection policies and GDPR regulations, only de-identified data will be shared. External researchers may be granted access to anonymized datasets upon reasonable request, subject to approval by the principal investigator and relevant institutional bodies (and their Institutional Review Boards), and following the completion of a data sharing agreement.

Any significant protocol modifications, such as changes to eligibility criteria, outcomes, or analyses, will be promptly communicated to all relevant stakeholders through revised documentation.

Participant adherence and study retention

The trial approach is highly pragmatic, making it voluntary for participants to apply ERGO throughout both phases. No restrictions on concomitant care were imposed. This pragmatic approach also applies to participants in the intervention group, who are asked to download and follow the IPET instructions provided in the app. The app includes built-in features of progress notifications, and reminders to complete exercises, but no direct supervision. Participants may withdraw from the trial at any time by contacting the corresponding author. All cases of attrition, including withdrawn consent, will be recorded with reasons for withdrawal or refusal to provide follow-up data when available. To maximize retention and ensure complete follow-up data, automatic e-mail reminders will be sent up to two times: 7 and 14 days after the initial questionnaire distribution. Periodic remote monitoring of data collection will be conducted via REDCap.

Statistical methods

The primary outcome variables are MSP at 12 and 20 weeks. The primary analysis will be conducted according to the intention-to-treat principle using a linear mixed model, with MSP at weeks 12 and 20 forming the dependent variable. The model will include time (12 weeks, 20 weeks), group allocation (intervention vs. control), and a time×group allocation interaction as fixed effects with baseline MSP intensity value as covariate. Random intercepts for participants and randomization blocks will be included to account for within-person correlation and clustering induced by block randomization. The primary effect of interest is the treatment-group difference at 20 weeks. Results will be presented with corresponding 95% confidence intervals. A two-sided significance level of 0.05 will be used for all statistical tests. Missing data will be handled under the missing-at-random assumption, inherent to the mixed-model approach, and the extent of missingness will be described by trial arm and key baseline characteristics.

Details of additional analyses are provided in the SAP, which will be made available on Clinicaltrails.gov before the completion of data collection and the start of analysis. To reduce the risk of biased interpretation of results, a blind interpretation will be conducted [57]. The procedure will involve drafting two interpretations based on a review of the primary outcome data, with groups arbitrarily labeled A and B. Interpretation 1 assumes that A is the intervention group and B the control group, while interpretation 2 assumes the reverse. After agreeing on both interpretations, the randomization code is broken, and the correct interpretation is selected.

Statistical analyses will be conducted using Stata, version 17 (StataCorp LLC, College Station, TX, USA) [58].

Monitoring

No independent data monitoring committee will be established, as the trial involves low-risk, non-invasive interventions (ergonomic education and structured exercise training) with no anticipated serious adverse events. Mild, short-term muscle soreness may occur but is considered an expected and harmless response to exercise. Safety will be monitored continuously by the study investigators, and any adverse events will be reported to the institutional ethics committee in accordance with regulatory requirements.

No interim analyses are planned, and no formal stopping guidelines have been established, as the intervention is considered low-risk and the trial duration is relatively short.

Discussion

This protocol describes a pragmatic trial investigating the effectiveness of IPET in addition to ERGO in reducing MSP among abdominal and pelvic surgeons at regional and academic medical centers in Denmark and the USA. The trial combines two interventions commonly investigated in other fields—ergonomic interventions and tailored physical exercise training—to enhance the evidence base for strategies aimed at preventing or rehabilitating surgeon MSP. Such pain is associated with fatigue and decreased surgical accuracy [29], burnout [59, 60], sick leave [61], and early retirement [8, 62].

Evidence from ergonomic and exercise interventions

Previous ergonomic interventions have focused on optimizing OR ergonomics and reduce surgeons’ physical strain during operations. These interventions have included ergonomic lectures or training [15, 63, 64], posture improving strategies [65–67], intraoperative microbreaks [28–30, 68], devices to reduce muscle activation [69, 70], and pre-and post-operative stretching exercises [71]. Despite the sound biomechanical rationale behind these studies and their promising findings, most studies are primarily observational in nature. As a result, their impact on reducing MSP remains unclear due to methodological limitations such as the lack of control groups, and infrequent or short follow-up periods between pre- and post-intervention outcome assessments, and the small sample sizes. Investigating the effects of ergonomic recommendations within a rigid study design, as the one proposed in this protocol, may offer a clearer picture of the effectiveness.

In contrast, strong evidence from systematic reviews supports workplace strength training as an effective strategy for reducing MSP among physically demanding professions [21, 72], including health care workers, nurses, and hospital employees. As strength training is a core component of IPET, the program has likewise demonstrated positive effects among individuals with existing MSP, including those in occupations with pain profiles similar to surgeons [39, 53–55, 73]. Our trial is among the first to rigorously combine tailored strength training offered by IPET with ergonomic recommendations in this population. This combined approach may generate synergistic effects for mitigating surgeon MSP.

Methodological considerations

This trial protocol proposes a pragmatic randomized controlled design, which enhances external validity. The participating centers comprised regional and academic hospitals in Denmark and North America where study participants were employed; however, it is not known whether these centers are representative of the broader population of surgeons. Several other methodological considerations warrant discussion.

Eligibility criteria and participant inclusion

The overall pragmatic approach in this trial may impact internal and external validity in different ways, serving both as a limitation and a strength. For example, the eligibility criterion requiring a minimum average of 4 h of surgery per week was set arbitrarily. This threshold aimed to ensure a sufficient participant pool, while ensuring sufficient surgical exposure (case load/surgery time). A higher threshold might have excluded relevant surgeons, whereas a lower threshold might have included surgeons with insufficient surgical exposure.

The intervention is designed as a workplace-initiated intervention to manage MSP, and is applicable to all surgeons, regardless of current pain status. However, including participants without MSP may reduce the observable contrast in the primary outcome. Therefore, randomization is stratified by pain case status to enable analysis of the entire sample and of those reporting baseline pain.

App-based delivery and supervision

Previous IPET studies allowed workers to perform IPET during working hours, often with some degree of supervision [39, 53–55]. In contrast, the present trial delivers IPET via a mobile app, using elastic resistance bands for individualized, unsupervised training. This format offers flexibility, allowing surgeons to engage in IPET in their leisure time, or in the downtime between surgical cases, as there is the option to split the weekly 50 min of IPET into shorter sessions. This flexibility is intended to facilitate the integration of IPET into daily life. However, the absence of direct supervision, aside from the app-based support features, may hinder the efficacy of intervention delivery. Although this concern did not emerge among office workers who obtained comparable outcomes with or without supervision [34], these findings may not directly translate to surgeons. Nevertheless, a recent systematic review found that mobile app-interventions with tailored physical exercise programs reduced MSP by 1.4 points (95% CI: 0.6 to 2.2) on a 0–10 NRS [74]. This reduction in MSP aligns with the minimum clinically important difference (MCID) defined in the present trial, supporting the potential effectiveness of the app-based delivery model despite the absence of direct supervision.

Self-reported outcomes and measurement limitations

The pragmatic approach of the trial also extends to outcome data collection, which relies solely on online questionnaires. Unlike previous IPET trials that used objective physical measurements such as relative VO_2max, muscle strength tests, body fat percentage, and blood pressure [35], this approach saves time and resources for participants and researchers. It also tests the scalability of delivering IPET through a mobile app, thereby enhancing external validity. However, it might result in less precise estimates for variables like muscle strength and cardiorespiratory fitness. That said, given that MSP is the primary outcome, and the fact that surgeons are considered to have a high level of health literacy, the risk of bias associated with self-reported data is considered to be minimal.

Risk of contamination and control measures

There is a potential risk of contamination between the intervention and control groups, as participants are individually randomized and are aware of their group assignment. This could potentially reduce the contrast in outcomes between the groups [38, 75], offsetting any observable intervention effects. To address this, the trial was designed so group allocation does not influence interactions within OR: the ERGO guideline applies equally to all surgeons, regardless of allocation, while IPET is intended to be performed during non-operative or leisure time. Although performing IPET during work hours was mentioned as a possibility because that was the protocol in previous IPET trials, surgeons from a previous study have indicated that this is not feasible in their profession [76]. Further, access to the IPET app is restricted through unique activation codes, which are exclusively provided to the intervention group participants. This ensures that app-based teams can only be formed within this group. Additionally, to minimize the risk of protocol deviations, the control group is offered access to IPET after the trial period ends.

In summary, this pragmatic trial is expected to provide valuable insights into the effectiveness of app-delivered IPET as a preventative and rehabilitative strategy for MSP among abdominal and pelvic surgeons. Such findings may represent an important step towards improving surgeon well-being and addressing broader concerns about workforce sustainability and potential surgeon shortages.

Trial status

This is protocol version number 2, dated 2025 June 11. The recruitment began in December 2023, and the recruitment is expected to be completed in October 2025.

Abbreviations

ERGO

Ergonomic recommendations

GP

General practitioner

IPET

Intelligent physical exercise training

MSP

Musculoskeletal pain

NRS

Numerical rating scale

SAP

Statistical analysis plan

Authors’ contributions

TD and OM conceived the overall aim of the trial, and OM is the grant holder. HJC, OM, and TD designed the trial. HJC, PTJ, OM, LFS, HN, SH, TD, and KC contributed to the manuscript preparation and trial conduct planning. All authors read and approved the manuscript for publication.

Funding

Financial funding was provided by the Work Environment Research Fund and Aarhus University. The funding sources have not been involved in the design of this trial and will not be part of any execution, analysis, or interpretation of the data, or decisions to publish results.

Data availability

Data sharing is not applicable to this protocol article as no datasets will be generated or analyzed.

Declarations

Ethics approval and consent to participate

The Scientific Ethics Committees for the Central Denmark Region reviewed the protocol and found the trial to be exempted from ethics approval (ref no. 1–10-72–124-22). The institutional ethics review board of Aarhus University approved the trial (ref. no. 2023–009). Informed consent will be obtained electronically through an online questionnaire.

Consent for publication

Not applicable—study protocol (no data generated).

Competing interests

The authors declare no competing interests.