Doctor, when can I drive? - compensation capability while driving with restricted elbow - a biomechanical analysis.

BACKGROUND

Every joint participates in a specific range of motion (ROM) while operating a motor vehicle safely. In current literature, there is a paucity of how movement restrictions of the elbow flexion and extension can be compensated by adjacent joints to ensure safe driving. The aim of this study was to analyze movement patterns of the kinematic chain consisting of wrist, elbow, and shoulder while driving with restricted elbow joint.

METHODS

Twenty participants completed a driving course in a driving simulator in two conditions: a) free ROM of all joints vs. b) restricted right elbow in 90° flexion but with free pronation and supination. To evaluate driving performance, speed, lane accuracy, and shifting time was measured. To analyze the movement pattern, ROM of wrist, elbow, and shoulder were recorded using a full-body motion capture system. Each driving course consisted of three maneuvers, as follows: I shifting, II left turns, and III right turns. Driving performance and movement patterns of condition a) and b) were compared on maneuver I-III.

RESULTS

Driving performance: Participants drove their car slower while driving right turns with elbow restriction (a) 37.45 ± 1.66 km/h vs. b) 32.53 ± 1.18 km/h; P = .02). Driving performance was not affected while driving left turns or shifting gears (P > .05). Movement pattern: Participants used their right shoulder in a higher ROM while driving turns with restricted right elbow (P < .05) but the left arm showed no significant different movement pattern (P > .05). The ROM of the left elbow and both shoulders were significantly higher when shifting gears with restricted right elbow (P < .05).

CONCLUSION

This study first describes the changes in movement patterns of the upper extremity while driving with a restricted right elbow. Our data suggest that restricted right elbow flexion or extension can be compensated by the left arm and a different posture of the right shoulder when driving left turns. A different movement pattern of the left elbow and both shoulders is used when changing gears while driving straight. Drivers should be aware when driving turns while shifting gears, and special attention should be paid to the shoulders and left elbow when evaluating the driving capability of patients with movement restriction of the right elbow by physicians.