Injury patterns among pedestrians using assistive mobility devices

Abstract

Introduction: As the population ages, growing numbers of individuals are turning to assisted mobility devices (AMDs) to maintain independence. These devices often place users in a seated position. Like ambulatory pedestrians, pedestrians seated in an AMD are at risk for involvement in an automobile versus pedestrian crash. The purpose of this study is to compare the injury pattern and comorbidities of standing pedestrians struck by an automobile versus those of seated pedestrians.

Methods: The Arizona State Trauma Registry was queried for pedestrians struck by an automobile between 2010 and 2015. Using ICD 9 and 10 codes as well as other available documentation, seated pedestrians were identified and matched based on age and gender to standing pedestrians. Presence of co-morbidities, injury pattern, Injury Severity Score (ISS), hospital length of stay (LOS), and mortality were compared between the two groups.

Results: There were 70 seated pedestrians identified, matched to 140 standing pedestrians. Co-morbidities were present in 89% of seated pedestrians vs 66% of standing pedestrians (p = 0.002). Functional dependence was more prevalent in the seated pedestrians (21% vs 1%, p = 0.004). There were not significant differences in the proportion of AIS injuries by body region. However, within the thoracic region, seated pedestrians were more likely to suffer pulmonary contusions: 14% vs 4%, p = 0.05.

Conclusions: The injury pattern for seated pedestrians differs slightly from that of standing pedestrians struck by an automobile. However, seated pedestrians are more likely to have co-morbid conditions that may complicate care. These findings are important when caring for the injured pedestrian and performing injury prevention outreach.

Keywords: Assistive mobility device; Automobile; Injury pattern; Kinematics; Pedestrian.