title: Ergonomic analysis of primary and assistant surgical roles.
abstract: Laparoscopic surgery is associated with a high degree of ergonomic stress. However, the stress associated with surgical assisting is not known. In this study, we compare the ergonomic stress associated with primary and assistant surgical roles during laparoscopic surgery. We hypothesize that higher ergonomic stress will be detected in the primary operating surgeon when compared with the surgical assistant.
  
  
  
  One right-hand dominant attending surgeon performed 698 min of laparoscopic surgery over 13 procedures (222 min primary and 476 min assisting), whereas electromyography data were collected from bilateral biceps, triceps, deltoids, and trapezius muscles. Data were analyzed in 1-min segments. Average muscle activation as quantified by maximal voluntary contraction (%MVC) was calculated for each muscle group during primary surgery and assisting. We compared mean %MVC values with unpaired t-tests.
  
  
  
  Activation of right (R) biceps and triceps muscle groups is significantly elevated while operating when compared with assisting (R biceps primary: 5.47 ± 0.21 %MVC, assistant: 3.93 ± 0.11, P < 0.001; R triceps primary: 6.53 ± 0.33 %MVC, assistant: 5.48 ± 0.18, P = 0.002). Mean activation of the left trapezius muscle group is elevated during assisting (primary: 4.33 ± 0.26 %MVC, assistant: 5.70 ± 0.40, P = 0.024). No significance difference was noted in the other muscle groups (R deltoid, R trapezius, left [L] biceps, L triceps, and L deltoid).
  
  
  
  We used surface electromyography to quantify ergonomic differences between operating and assisting. Surgical assisting was associated with similar and occasionally higher levels of muscle activation compared with primary operating. These findings suggest that surgical assistants face significant ergonomic stress, just as operating surgeons do. Steps must be taken to recognize and mitigate this stress in both operating surgeons and assistants.
authors.affiliation: Department of Surgery, Section of Minimally Invasive Surgery, Washington University School of Medicine, St. Louis, Missouri. Electronic address: zihnia@wudosis.wustl.edu.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Zihni
authors.affiliation: Department of Surgery, Section of Minimally Invasive Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Jaime A
authors.initials: JA
authors.lastname: Cavallo
authors.affiliation: Department of Surgery, Section of Minimally Invasive Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Shuddhadeb
authors.initials: S
authors.lastname: Ray
authors.affiliation: Department of Industrial and Manufacturing Engineering, Southern Illinois University Edwardsville, Edwardsville, Illinois.
authors.forename: Ikechukwu
authors.initials: I
authors.lastname: Ohu
authors.affiliation: Department of Industrial and Manufacturing Engineering, Southern Illinois University Edwardsville, Edwardsville, Illinois.
authors.forename: Sohyung
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Surgery, Section of Minimally Invasive Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Awad
mesh_terms: D004576:Electromyography; D006804:Ergonomics; D006801:Humans; D010535:Laparoscopy; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D066231:Surgeons
keywords: Electromyography; Ergonomics; Human factors; Laparoscopic surgery; Surgical assistants