Influence of handle design on the surgeon's upper limb movements, muscle recruitment, and fatigue during endoscopic suturing.
BACKGROUND: Thus far, little has been done to investigate the kinematics (motion analysis) and kinetics (muscle work, muscle fatigue, comfort) of surgeons during laparoscopic surgery. Therefore, we set out to study these ergonomic aspects of task performance in the dominant upper limb of surgeons during endoscopic suturing. METHODS: Three different handles - conventional finger loop, rocker, and ball handle prototype - were compared in a study involving 10 surgeons suturing porcine enterotomies with each of the three instruments. The endpoints were performance parameters, motion analysis and muscle work, and fatigue of the surgeon's dominant upper limb; subjective scores for comfort level and maneuverability were also elicited from the subjects. RESULTS: Task quality and efficiency during endoscopic suturing, were significantly better with the ball and rocker handle needle drivers than with the finger loop instrument, with lower angular velocity at the elbow and shoulder joints, more pronation, and less supination. The integrated muscle work was much lower for both the rocker and the ball handles. Significant muscle fatigue, especially of the arm flexors and deltoid, was observed only with finger loop instruments. Comfort and maneuverability rating scores were higher with both handles than with the conventional finger loop. The ball handle was easier to maneuver, but it was somewhat less comfortable than the rocker system. CONCLUSION: A different pattern of joint movements, a reduction in muscle power exerted during endoscopic suturing, and hence an absence of muscle fatigue were documented with ergonomic needle drivers (rocker and ball) when compared to the conventional finger loop instruments. These differences translate to better and more efficient task performance with enhanced comfort.