An ergonomics study on wrist posture when using laparoscopic tools in four techniques in minimally invasive surgery.

PURPOSE: With reference to four minimally invasive surgery (MIS) cholecystectomies, the aims were (a) to recognize the factors influencing dominant wrist postures manifested by the surgeon; (b) to detect risk factors involved in maintaining deviated wrist postures; (c) to compare the wrist postures of surgeons while using laparoscopic tools.

METHODS: Video films were recorded during live surgeries. The films were synchronized with wrist joint angles obtained from wireless electrogoniometers placed on the surgeon's hand. The analysis was conducted for five laparoscopic tools used during all surgical techniques.

RESULTS: The most common wrist posture was extension. In the case of one laparoscopic tool, the mean values defining extended wrist posture were distinct in all four surgical techniques. For one type of surgical technique, considered the most beneficial for patients, more extreme postures were noticed regarding all laparoscopic tools. We recognized a new factor, apart from the tool's handle design, that influences extreme and deviated wrist postures. It involves three areas of task specification including the type of action, type of motion patterns and motion dynamism.

CONCLUSIONS: The outcomes proved that the surgical technique which is best for the patient imposes the greatest strain on the surgeon's wrist. .