The Ergonomic Comparison of Endoscopist's Hand/Arm Movement and Relevant Muscle Load Between the Diagnostic and Therapeutic Upper Gastrointestinal Endoscopy

OBJECTIVES: There have been little quantitative studies of ergonomics in the upper gastrointestinal endoscopy. We aimed to identify the ergonomic characteristics of both diagnostic (esophagogastroduodenoscopy; EGD) and therapeutic (endoscopic submucosal dissection; ESD) endoscopy in terms of the movement range of the endoscopist's hand/arm holding the endoscope and muscle activity during procedures, in a preclinical setting. METHODS: (1) Optical reflective markers attached to the standard flexible endoscope were traced using a multiple motion capture system during EGD and ESD. The data were processed to generate three-dimensional XYZ coordinate data for each procedure. (2) Wireless electromyogram electrodes were attached to eight muscles in the left hand, forearm, shoulder, neck and back. Muscle activation during EGD and ESD was assessed as % maximal voluntary contraction (%MVC). RESULTS: (1) The motion capture was performed during 13 EGDs and 12 ESDs. On all XYZ axes, the movement range of the endoscope was significantly smaller during ESD than EGD (X; p < 0.001, Y; p = 0.015, Z; p < 0.001). (2) The EMG was recorded during 15 EGDs and eight ESDs. The higher mean %MVC of the pronator teres muscle (52.1%) and the extensor carpi radialis muscle (39.3%) was observed during all procedures. The %MVC tended to be higher during ESD (34.1%) than EGD (28.9%) in an analysis including all muscles (p = 0.078). CONCLUSIONS: Our study is the first to show therapeutic endoscopy had the smaller movement range of the endoscope, but the larger muscle activity than diagnostic endoscopy. These data could deepen our ergonomic understanding of endoscopy and help to optimize endoscopic techniques and/or relevant working environment.