Background: The aim of this study was to determine whether immobilization of an arm has detrimental effects on driving performance.
Methods: Thirty-six healthy officers-in-training were assigned a sequence of fiberglass splints (left and right-sided above-the-elbow thumb spica and below-the-elbow splints) with use of a randomized higher-order crossover design. Runs were scored on a cone-marked driving course used for officer certification with predetermined passing requirements. Driving time, the number of cones hit per course section, and the cone-adjusted total time (a five-second penalty per hit cone) were recorded. A linear mixed-effect model with random environmental and learning effects for cone-adjusted time analysis was used. Participants rated perceived driving difficulty and safety with each splint, and ratings were compared with the Wilcoxon signed-rank test.
Results: Thirty participants completed the entire set of runs. Analysis of total cone-adjusted time revealed a significant performance decrease with the left arm in an above-the-elbow thumb spica splint (average, 22.2 seconds; p < 0.001) and with the left arm in a below-the-elbow splint (average, 16.2; p = 0.007). Analysis of forward-only course sections revealed poorer performance trends with all splints, with the worst performance with the left arm in an above-the-elbow thumb spica splint. Driving with the left arm in an above-the-elbow thumb spica splint had the highest perceived difficulty (median, 8.0) and lowest perceived safety (median, 3.0).
Conclusions: Driving performance as measured with a standardized track and scoring system was significantly degraded with splint immobilization of the left arm. Further studies are required to determine the effect of arm immobilization on normal driving conditions.
1Vanderbilt Orthopaedic Institute, Vanderbilt University Medical Center, Medical Center East, South Tower, Suites 4200 (P.Y.C.) and 3200 (J.T.W., D.R.W., J.H.R., and D.H.L.), 1215 21st Avenue South, Nashville, TN 37232
2Department of Biostatistics, Vanderbilt University Medical Center, 571 Preston Building, Nashville, TN 37232-6848