Exploring hand coordination as a measure of surgical skill

The study aim was to identify residents' coordination between dominant and nondominant hands while grasping for sutures in a laparoscopic ventral hernia repair procedure simulation. We hypothesize residents will rely on their dominant and nondominant hands unequally while grasping for suture.

Surgical residents had 15 min to complete the mesh securing and mesh tacking steps of a laparoscopic ventral hernia repair procedure. Procedure videos were coded for manual coordination events during the active suture grasping phase. Manual coordination events were defined as: active motion of dominant, nondominant, or both hands; and bimanual or unimanual manipulation of hands. A chi-square test was used to discriminate between coordination choices.

Thirty-six residents (postgraduate year, 1-5) participated in the study. Residents changed manual coordination types during active suture grasping 500 times, ranging between 5 and 24 events (M = 13.9 events, standard deviation [SD] = 4.4). Bimanual coordination was used most (40%) and required the most time on average (M = 20.6 s, SD = 27.2), while unimanual nondominant coordination was used least (2.2%; M = 7.9 s, SD = 6.9). Residents relied on their dominant and nondominant hands unequally (P < 0.001). During 24% of events, residents depended on their nondominant hand (n = 120), which was predominantly used to operate the suture passer device.

Residents appeared to actively coordinate both dominant and nondominant hands almost half of the time to complete suture grasping. Bimanual task durations took longer than other tasks on average suggesting these tasks were characteristically longer or switching hands required a greater degree of coordination. Future work is necessary to understand how task completion time and overall performance are affected by residents' hand utilization and switching between dominant and nondominant hands in surgical tasks.