Dynamic postural control in injured collegiate cross-country runners is not associated with running-related injury.

BACKGROUND: Biomechanical factors have been associated with running-related injury, but associations are unclear. Dynamic postural stability may be a factor related to injury that has not been studied extensively. RESEARCH QUESTION: Does dynamic postural control differ in those with a history of running-related injury or those who go on to sustain a running-related injury? METHODS: Sixty-five (45 injured; 20 uninjured) and fifty-eight (13 injured; 45 uninjured) collegiate cross-country runners were available for our retrospective and prospective analyses. Time to stabilization and dynamic postural stability index were collected during two separate jump landing tasks (forward and lateral direction) for each leg. Retrospective injury was tabulated by a running history survey. Prospective injuries were recorded by a licensed athletic trainer during the competitive season. Differences in postural stability were compared between injured and uninjured groups and between limbs using two-way ANOVA's. An overall group by leg comparison was completed for each task. RESULTS: The non-dominant limb demonstrated better postural stability indices regardless of injury history. An interaction was observed between limbs and history of injury for the anterior-posterior time to stabilization for the lateral task. The non-dominant limb demonstrated better medio-lateral postural stability indices and time to stabilization during the lateral task, regardless of prospective injury. SIGNIFICANCE: Dynamic postural stability was reduced in the dominant limb, but no clear differences were seen between injured and uninjured runners. This suggests dynamic postural stability may be altered in individuals with a history of a running-related injury, but no relationship to subsequent injury was substantiated. Further work is needed to understand how dynamic postural stability may be related to running-related injury.

Error tolerance: an evaluation of residents' repeated motor coordination errors.

BACKGROUND: The study investigates the relationship between motor coordination errors and total errors using a human factors framework. We hypothesize motor coordination errors will correlate with total errors and provide validity evidence for error tolerance as a performance metric. METHODS: Residents' laparoscopic skills were evaluated during a simulated laparoscopic ventral hernia repair for motor coordination errors when grasping for intra-abdominal mesh or suture. Tolerance was defined as repeated, failed attempts to correct an error and the time required to recover. RESULTS: Residents (N = 20) committed an average of 15.45 (standard deviation [SD] = 4.61) errors and 1.70 (SD = 2.25) motor coordination errors during mesh placement. Total errors correlated with motor coordination errors (r[18] = .572, P = .008). On average, residents required 5.09 recovery attempts for 1 motor coordination error (SD = 3.15). Recovery approaches correlated to total error load (r[13] = .592, P = .02). CONCLUSIONS: Residents' motor coordination errors and recovery approaches predict total error load. Error tolerance proved to be a valid assessment metric relating to overall performance.

Working volume: validity evidence for a motion-based metric of surgical efficiency.

BACKGROUND: The aim of this study was to evaluate working volume as a potential assessment metric for open surgical tasks. METHODS: Surgical attendings (n = 6), residents (n = 4), and medical students (n = 5) performed a suturing task on simulated connective tissue (foam), artery (rubber balloon), and friable tissue (tissue paper). Using a motion tracking system, effective working volume was calculated for each hand. Repeated measures analysis of variance assessed differences in working volume by experience level, dominant and/or nondominant hand, and tissue type. RESULTS: Analysis revealed a linear relationship between experience and working volume. Attendings had the smallest working volume, and students had the largest (P = .01). The 3-way interaction of experience level, hand, and material type showed attendings and residents maintained a similar working volume for dominant and nondominant hands for all tasks. In contrast, medical students' nondominant hand covered larger working volumes for the balloon and tissue paper materials (P < .05). CONCLUSIONS: This study provides validity evidence for the use of working volume as a metric for open surgical skills. Working volume may provide a means for assessing surgical efficiency and the operative learning curve.

Advanced Engineering Technology for Measuring Performance.

The demand for competency-based assessments in surgical training is growing. Use of advanced engineering technology for clinical skills assessment allows for objective measures of hands-on performance. Clinical performance can be assessed in several ways via quantification of an assessee's hand movements (motion tracking), direction of visual attention (eye tracking), levels of stress (physiologic marker measurements), and location and pressure of palpation (force measurements). Innovations in video recording technology and qualitative analysis tools allow for a combination of observer- and technology-based assessments. Overall the goal is to create better assessments of surgical performance with robust validity evidence.

Operative skill: quantifying surgeon's response to tissue properties.

BACKGROUND: The aim of this study was to investigate how tissue characteristics influence psychomotor planning and performance during a suturing task. Our hypothesis was that participants would alter their technique based on tissue type with each subsequent stitch placed while suturing. MATERIALS AND METHODS: Surgical attendings (n = 6), residents (n = 4), and medical students (n = 5) performed three interrupted sutures on different simulated materials as follows: foam (dense connective tissue), rubber balloons (artery), and tissue paper (friable tissue). An optical motion tracking system captured performance data from participants' bilateral hand movements. Path length and suture time were segmented by each individual stitch placed to investigate changes to psychomotor performance with subsequent stitch placements. Repeated measures analysis of variance was used to evaluate for main effects of stitch order on path length and suture time and interactions between stitch order, material, and experience. RESULTS: When participants sutured the tissue paper, they changed their procedure time (F(4,44) = 5.14, P = 0.017) and path length (F(4,44) = 4.64, P = 0.003) in a linear fashion with the first stitch on the tissue paper having the longest procedure time and path length. Participants did not change their path lengths and procedure times when placing subsequent stitches in the foam (P = 0.910) and balloon materials (P = 0.769). CONCLUSIONS: This study demonstrates quantifiable real-time adaptation by participants to material characteristics during a suturing task. Participants improved their motion-based performance with each subsequent stitch placement indicating changes in psychomotor planning or performance. This adaptation did not occur with the less difficult tasks. Motion capture technology is a promising method for investigating surgical performance and how surgeons adapt to operative complexity.

Idle time: an underdeveloped performance metric for assessing surgical skill.

BACKGROUND: The aim of this study was to evaluate validity evidence using idle time as a performance measure in open surgical skills assessment. METHODS: This pilot study tested psychomotor planning skills of surgical attendings (n = 6), residents (n = 4) and medical students (n = 5) during suturing tasks of varying difficulty. Performance data were collected with a motion tracking system. Participants' hand movements were analyzed for idle time, total operative time, and path length. We hypothesized that there will be shorter idle times for more experienced individuals and on the easier tasks. RESULTS: A total of 365 idle periods were identified across all participants. Attendings had fewer idle periods during 3 specific procedure steps (P < .001). All participants had longer idle time on friable tissue (P < .005). CONCLUSIONS: Using an experimental model, idle time was found to correlate with experience and motor planning when operating on increasingly difficult tissue types. Further work exploring idle time as a valid psychomotor measure is warranted.