The presented study shows the everyday unadorned muscular tension experienced by an ear surgeon during highly demanding cochlear implantations while using a conventional tripod microscope. In line with other studies, such surgeries could lead into a head-bent and back-bent position with resulting in work-related musculoskeletal disorders [7].

A new technology of using a HMD for steering the camera head, now provides the opportunity for an upright, no longer stooped posture. It could be shown that there is a reduction of 40% of muscle tension while using a RoboticScope®, expected caused due to the upright relaxed body position.

Interestingly, there was a higher muscle tension in resting position before starting surgery in comparison to the post-surgery measurement. This observation may hint, that a certain mental tension, before a potentially challenging surgery, can lead to higher muscle tension. However, there was a significant bigger difference from pre- to post-surgery measurement while using the conventional microscope.

All surgeons were right-handed. In line with this there was higher muscle tension on the right upper trapezius muscle independent of the sight of surgery and independent of the used microscope. Nevertheless, while performing surgery on the right ear there was seen a lower muscle tension. This may be driven by the possibility for resting the right arm on the operating table while operating the right ear.

It could therefore be questioned, if a storage option for the right arm should be arranged during surgery on the left ear, to also reduce the muscle tension of the surgeon independent of the microscope. This assumption is supported by the findings of Vijendren et al. 2019, who showed a reduction in muscular complaints in microscope based surgery while using a special chair, which holds the operator’s head and provides armrests [11].

With a higher BMI, the surgeon’s sitting position could be impaired, as he or she sits further away from the patient due to the abdomen and arm and would therefore have to operate from a more outstretched arm. Surprisingly, there was no correlation between the BMI of the patient and the muscle tension of the surgeon. This could be caused due to the condition, that not the tissue overall but the degree of pneumatisation of mastoid bone has an influence of the effort of the surgery. The pneumatisation of mastoid bone depends on the development in childhood and has no primary relation to weight [12], therefore no connection between BMI and pneumatisation can be established.

As far as observed, there was an increase in muscle tension associated with the number of surgeries already performed by the surgeon on that day. While using the RoboticScope® there was only an increase from the first to the second surgery, which was much lower than the increase using the conventional microscope. Hence, it seems that the muscle tension caused by the bent over body position while using a conventional microscope intensifies over the course of the day and across the number of surgeries. This is in line with Schechet et al., who showed on the example of ophtalmologists, that surgeons who are doing a lot of surgeries and spending a lot of time in the operating theatre are at risk for musculoskeletal disorders [13].

Regarding subjective parameters of the performed surgery the perceived difficulty level of the surgery has an influence of the muscle tension regardless of the microscope. More demanding surgeries lead into a higher muscle tension. However, from the second to the third surgery a decrease was noted, but it needs to be mentioned that only three surgeries were classified as high level, so that it might be difficult to make a reliable statement here.

An intriguing observation of the study reveals that especially when using the conventional microscope, high physical activity of the surgeon on the previous day leads to a reduction in muscle tension during the operation. This appears to be an important finding. Naturally, we were able to clearly demonstrate that new microscope techniques such as the RoboticScope® lead to a significant physiological improvement in the conditions of the operation. One could also venture to hypothesize that more relaxed operating conditions lead to better surgical outcomes. However, the conventional microscope is not likely to disappear from the everyday life of an ENT doctor in the near future, so it is necessary to consider in which way the conditions at the conventional microscope can be improved. Promoting physical activity in everyday life improves the conditions of the surgeon in their profession. In Germany, it is common practice in many companies to improve the physical activity and fitness of the employees. However, this is by no means commonplace in hospitals. Therefore, it is important to conduct studies that identify and highlight possible improvements in working conditions with the conventional microscope.

The work underlies the typical constraints of a prospective clinical single-center study based on a small study population. Even though 58 cochlear implant surgeries in a few months in a single-center are a lot, statistically significant statements are difficult to make. In addition we only conducted the study with two experienced surgeons with most expertise to exclude a bias.

Results of the presented study could be regarded as hypothesis generating and more studies should be conducted. Whether the reduction in tension on the back has a long-term effect and leads to fewer back problems cannot be answered from the study. In the study, we were able to measure the maximum and minimum tension as well as the mean tension during the operation. The respective parameters are subject to fluctuations and are susceptible to artifacts.