Ergonomics in the OR: An Electromyographic Evaluation of Common Muscle Groups Used During Simulated Flexible Ureteroscopy – a Pilot Study

Objective To assess the effects of different surgeon positions and ureteroscope types on muscle activation as measured by surface electromyography (sEMG) during simulated ureteroscopy in an endourology box-trainer model and the kidney phantom. Methods For this exploratory study, sEMG was used to quantify muscle activation of 3 endourology fellows during various ureteroscopic tasks. Electrodes were placed on the ureteroscope-holding side of the following muscles: thenar, forearm flexor, forearm extensor, biceps, triceps, deltoid, and trapezius. Subjects wore fitted lead aprons in an operating room and used a cystoscopy table with surgical drapes and an endoscopic video tower. Trials were completed with a disposable and reusable ureteroscope, both in the standing and sitting positions. Each subject performed an identical set of tasks in a phantom silicone kidney and ureteroscopy box trainer to recreate the procedural components of basketing, navigating a renal collecting system, and dusting. Raw EMG data for each task was processed and normalized as a percent of each subject's maximum voluntary contraction to allow comparison. Results The forearm extensor was the most heavily utilized muscle. The trapezius and deltoid muscles were activated more during sitting whereas the forearm flexors had increased activity during standing. The heavier reusable ureteroscope had increased forearm extensor activation compared to the disposable ureteroscope. Conclusion Preliminary data show measurable differences in muscle activation based on both surgical posture and type of ureteroscope used. This highlights the need for more extensive EMG studies to identify techniques and equipment to optimize ergonomics and potentially minimize injury during flexible ureteroscopy.