Peer-reviewed article

Children's Height and Injury Risk With Child Restraint Systems.

Tung HF, Huang JF, Tang JM, Hu CH, Chai SW et al. · 1 Jul 2026

Summary

Written by AI, not yet AICS's view · claude-haiku-4-5-20251001

This study examined how children's height affects injury patterns when using child restraint systems versus seat belts during motor vehicle crashes. Researchers analyzed data from over 6,500 children aged 6 to 11 years who were treated at trauma centers between 2017 and 2020. The findings show that the relationship between restraint type and injury patterns changes as children grow, suggesting that fixed age or height thresholds for transitioning from car seats to seat belts may not adequately protect all children.

Key points

Children using car seats had higher rates of severe head, neck, and spinal cord injuries compared to those using seat belts
The association between restraint type and injury patterns was nonlinear and dependent on child height
Among children measuring 110 to 140 cm tall, car seat use was associated with higher prevalence of severe spinal and thoracic injuries but lower abdominal injury
Current uniform age or height thresholds for transitioning from car seats to seat belts may not account for growth-specific vulnerabilities
The study included 6,503 children, of whom 1,066 (16.4%) had used a child restraint system

Limitations

This is a retrospective observational study of injured children only, so it does not provide information about injury prevention rates or absolute risk in the general population of children in vehicles. The analysis cannot establish causation and may be affected by unmeasured confounding factors related to crash severity or other circumstances.

Abstract

Importance The transition from child restraint systems (CRSs) to seat belts (SBs) is often based on fixed age or height thresholds. However, the association between height and injury patterns among injured children remains insufficiently characterized within clinical trauma settings. Objectives To examine the association between height and regional injury patterns among children involved in motor vehicle crashes evaluated at trauma centers and to assess how these patterns vary between CRS and SB users. Design, setting, and participants This retrospective cohort study of children 6 to 11 years old who were involved in motor vehicle crashes evaluated at trauma centers used inverse probability of treatment weighting with gradient boosting machine-derived propensity scores and restricted cubic spline modeling to evaluate height-dependent associations between protective device and injury pattern. Data from the American College of Surgeons-Trauma Quality Improvement Program (2017-2020) were used. Statistical analyses were conducted between June 1, and August 31, 2025. Main outcomes and measures Prevalence of severe regional injuries (Abbreviated Injury Scale score ≥3). Results A total of 6503 children aged 6 to 11 years (mean [SD] age, 8.48 [1.69] years; 3251 male [50.0%], 3252 female [50.0%]) were identified from the database; 1066 (16.4%) had used a CRS. After weighting, CRS use was associated with a higher prevalence of severe head and neck injury (13.9% vs 10.5%; odds ratio, 1.41; 95% CI, 1.06-1.88, P = .02) and severe spinal cord injury (2.9% vs 1.8%; odds ratio, 1.70; 95% CI, 1.02-2.84, P = .04) compared with SB use. Height-dependent analysis revealed a nonlinear association between restraint type and injury patterns. Among children measuring 110 to 140 cm, CRS use was associated with a higher prevalence of severe spinal and thoracic injuries, whereas the prevalence of abdominal injury was lower within the same height range. Conclusions and relevance In this cohort study, the association between protective devices and injury patterns was height dependent and nonlinear. A shift in regional injury anatomy was observed across the 110- to 140-cm spectrum, suggesting that a uniform threshold may not adequately characterize growth-specific vulnerabilities.

Findings the Hub has extracted

Each claim below is labelled by its type of design and links back to this report.

SurvivalProtection

Problem

Children's risk of injury in motor vehicle crashes and optimal timing for transitioning from child restraint systems to seat belts

Intervention: Use of child restraint systems (car seats) compared to seat belts for children aged 6 to 11 years
Population: Children aged 6 to 11 years involved in motor vehicle crashes evaluated at trauma centers in the United States (2017-2020)

Key finding

CRS use was associated with higher prevalence of severe head and neck injury (13.9% vs 10.5%; OR 1.41, 95% CI 1.06-1.88)

Experimental