Looks like a surgeon? Impact of anthropometry on the kinematics of surgical novices: counterbalanced cross-over design study of minimally invasive surgery

To investigate the relationship between anthropometric measurements of surgical novices and their upper-body kinematics during laparoscopic (LAP) and robotic assisted (RA) tasks. A counterbalanced crossover design study was conducted. Participants were assigned by systematic alternating allocation to first perform tasks on an Inovus laparoscopic trainer (LAP) or da Vinci Xi system (RA) in a simulation suite, whilst wearing three motion analysis sensors (upper left and right arms, and mid thoracic). In total 57 surgical novices (33 female, 24 male) were recruited. Kinematic data were available for 54 participants. Height, elbow height and arm span of female participants were significantly lower than male participants, 165.6 ± 5.42 cm, 107.9 ± 4.9 cm and 163.2 ± 10.2 cm versus 181 ± 8.3 cm 118.3 ± 6.6 cm and 182.7 ± 10.3 cm respectively (p < 0.0001). Greater jerk and angular velocity were demonstrated for LAP versus RA tasks (p < 0.0001). Significant interactions between anthropometry and surgical modality were observed; decreasing elbow height correlated with significantly greater angular velocity during LAP tasks (interaction p < 0.001; jerk p = 0.005), whereas no such relationship was observed for RA tasks. The interactions for height did not remain significant after correction for multiple comparisons. There is an inverse relationship between anthropometric measurements (in particular elbow height) and angular velocity recorded during simulated LAP, but not RA, tasks. Surgical novices at the lower end of the anthropometric spectrum exhibit significantly greater angular velocity and jerk when performing LAP compared to RA tasks. These kinematic differences provide a plausible mechanistic hypothesis for the higher rates of work-related musculoskeletal injuries reported in laparoscopy, requiring future longitudinal investigation.