Quantification of motion characteristics and forces applied to tissues during suturing

Background The quantification of movement processes describes how a movement is generated. These process measures have been shown to be effective sources of feedback to facilitate motor learning and can thus be applied to teach fundamental technical skills in surgery. The aim of this study was to determine, through detailed analyses, whether specific process measures of hand motions and forces imposed on tissues during suturing were sensitive to (1) practice and (2) levels of surgical expertise. Methods Six junior surgical residents (PGY-1) and 7 faculty surgeons were required to perform 20 simulated sutures on an artificial artery model, during which time the performers’ hand movements were tracked by electromagnetic markers and the quantity of force they applied was measured by a force platform holding the arterial suturing models. The amount of wrist rotation and peak hand velocity produced during the suturing movement, peak and average forces applied to the tissue, the temporal difference between force and wrist rotation onsets, and the total suturing time were evaluated. Results Surgeons showed greater wrist rotation, higher average forces, shorter force-rotation initiation times, and shorter suturing times than did junior residents. Only the amount of wrist rotation and the time elapsed between force and wrist rotation onsets improved with practice for the junior group. Conclusions Although all 4 variables measured can be used to distinguish between expert and novice performances, only the process measures (wrist rotation and force-rotation initiation time) changed as a result of practice for the junior residents. Thus, these measures can be used to facilitate skills learning by serving as a source of detailed structured feedback to trainees.