Higher physical workload risks with NOTES versus laparoscopy: a quantitative ergonomic assessment Gyusung Lee • Erica Sutton • Tameka Clanton • Adrian Park Received: 5 May 2010 / Accepted: 8 October 2010 Ó Springer Science+Business Media, LLC 2010 Abstract Background Research confirms that surgeons experience physical symptoms due to the unfavorable ergonomics of laparoscopy. The physical effects of performing Natural Orifice Transluminal Endoscopic Surgery (NOTES)— potentially the next evolutionary surgical step—are only now being quantitatively and systematically assessed. This study investigates NOTES- and laparoscopy-related phys- ical workloads through biomechanical analyses. Methods Fourteen surgeons with varying laparoscopic experience were recruited. Each participant completed ring transfer and triangle transfer tasks using two surgical platforms: laparoscopy and NOTES. Motion capture and electromyography (EMG) systems recorded biomechanical data for quantitative physical workload assessment. The normalized cumulative muscular workload (NCMW) and mean muscular workload (MMW) were obtained from EMG data. Then normalized performance time (NPT) was compared between the two surgical platforms. The overall NCMW was considerably greater when participants per- formed tasks using the NOTES platform (1315.8 ± 116.9%) compared with traditional laparoscopy (153.9 ± 18.8%). Results Performing NOTES required eight to nine times higher muscular workload (NCMW: NOTES 1315.8%, laparoscopy 153.9%, p \ 0.05) when compared with tra- ditional laparoscopy. This result was shown to be caused by the following: (1) six to eight times longer NPT with NOTES (p \ 0.05) and (2) higher average activation levels shown in regard to biceps, extensor digitorum communis, and thenar compartment (p \ 0.05), the muscles respon- sible for specific joint movements to hold and operate the scope. Conclusion This study demonstrated that performing NOTES is significantly more challenging for surgeons than laparoscopy. The greater amount of muscular exertion required is linked to higher ergonomic risks. Based on the depth and strength of our results, we propose that an alternative NOTES platform be designed, one that over- comes the awkward operational mechanism of the dual- working-channel flexible endoscope. Keywords Laparoscopy Á NOTES Á Ergonomics Á Physical workload Á Endoscopy Á MIS With Natural Orifice Transluminal Endoscopic Surgery (NOTES), intra-abdominal procedures are performed not with rigid laparoscopic instruments but with flexible instruments delivered via flexible endoscopes. The flexible endoscopes are designed to go through natural orifices, thus avoiding the need for abdominal wall incisions [1, 2]. Early experiences in both laboratory and human cases have Presented at the 12th WCES, April 14–17, 2010, National Harbor, MD. G. Lee Á E. Sutton Á T. Clanton Á A. Park (&) Division of General Surgery, Department of Surgery, School of Medicine, University of Maryland, 22 South Greene Street, Room S4B14, Baltimore, MD 21201, USA e-mail: apark@smail.umaryland.edu G. Lee e-mail: glee@smail.umaryland.edu E. Sutton e-mail: esutton@smail.umaryland.edu T. Clanton e-mail: tclanton@smail.umaryland.edu A. Park University of Maryland, Baltimore, MD, USA 123 Surg Endosc DOI 10.1007/s00464-010-1443-x