Intraoperative Ergonomics During Otologic Surgery as Measured by Surface Electromyography

Introduction: Previous studies have shown high rates of work-related musculoskeletal disorders (WRMD) among otolaryngologist-head and neck surgeons (OHNS). Poor surgical ergonomics can contribute to injury, pain, and reduced career longevity. Prior studies used survey data or measurements in controlled surgical simulations to characterize ergonomic risk. This study uses surface electromyography (sEMG) wireless sensors to assess surgeon muscle fatigue and strain during otologic procedures in the operating room.

Methods: Seven surgeons wore sEMG sensors over 20 otologic procedures on the upper trapezius (UT), anterior deltoid (AD), biceps of the dominant arm (DB), and biceps of the non-dominant arm (NB). Surveys, including the NASA Task Load Index (NTLX), were conducted to evaluate case difficulty and self-reported ergonomics, which were correlated to objective sEMG measurements.

Results: Worse surgeon ergonomics during a case led to higher mental demand (β = 17.9, p = 0.025), physical demand (β = 14.20, p = 0.018), and effort needed to perform the procedure (β = 12, p = 0.028). Moreover, as either UT average frequency (β = 0.9, p = 0.032), UT average amplitude (β = 0.45, p = 0.011), AD average amplitude (β = 1.26, p = 0.0028), or DB average amplitude increased (β = 1.03, p = 0.0072), NTLX overall score increased. An increase in NB average amplitude was also seen to increase mental demand (β = 2.20, p = 0.043). Additionally, as either UT average frequency (β = 0.077, p = 0.015) or DB average amplitude increased (β = 0.062, p = 0.044), perceived difficulty of the case increased.

Conclusions: This study highlights an important first step in quantifying the relationship of muscle activity on surgeon workload in different otologic procedures. This data augments our current understanding of ergonomic risk over the course of an operating room procedure rather than at a single timepoint or in a surgical simulation.