ABSTRACT
BACKGROUND: Adding to the ergonomic inconveniences already presented by traditional laparoscopy (LAP), laparoendoscopic single-site (LESS) surgery has been found to entail other more specific problems, including greater reduction in movement freedom, in-line vision with loss of triangulation, and greater proximity of instruments. The objective of this study was to evaluate surgeons' ergonomy during LESS surgery, through the study of muscular activity, wrist angle, and hand movements, and compare it with conventional laparoscopy. METHODS: The study group was composed by 14 experienced laparoscopic surgeons, all right-handed. Each one performed dissection tasks on a physical simulator through LAP and LESS approaches. For LAP, straight laparoscopic scissors and dissector were used, whilst for LESS articulating tip scissors and dissector were chosen. During both tasks, muscular activity of biceps brachii, triceps brachii, forearm flexors and extensors, and trapezius muscles was registered through surface electromyography. Simultaneously right-hand movements and wrist angles were obtained through a motion capture data glove (CyberGlove(®)), which allowed for the use of a modified RULA test applied to the recorded angles with subsequent establishment of risk levels for the wrist joint. RESULTS: Muscular activity for trapezius (LAP 6.94 ± 4.12 vs. LESS 11.32 ± 4.68; p ≤ 0.05) and forearm extensor muscles (LAP 9.2 ± 2.45 vs. LESS 37.07 ≤ 16.05; p ≤ 0.001) was significantly lower in conventional laparoscopy compared with LESS approach. No statistical significance was obtained between the different sensors, except in 3 of the 11 analyzed CyberGlove(®) sensors. The modified RULA test showed a score of 3 for laparoscopy (unacceptable), whereas for LESS a score of 2 was obtained (acceptable), with statistically significant differences between them (p ≤ 0.05). CONCLUSIONS: The LESS approach entails greater level of muscular activity in the trapezius and forearm extensor muscles, but we have found evidences of a better wrist position during LESS compared with traditional laparoscopy.
