Cyclists fatalities: Forensic remarks regarding 335 cases

Bicycle injuries: A systematic review for forensic evaluation

Bicycles are employed as means of transportation across various age groups, from young students to the elderly, for work, education, health, and leisure trips. Despite not achieving high speeds, bicyclists remain vulnerable to severe and even fatal injuries when they are involved in traffic accidents. Although the rising awareness of ecological issues and traffic law enforcement mean that cyclists are increasingly susceptible to road traffic crashes and injuries. Injuries resulting from a traffic accident involving cyclists can show distinct and specific characteristics depending on the manner of occurrence. The aim of this study is to provide a systematic review of the literature on injuries sustained in cyclists involved in road accidents describing and analysing elements useful for forensic assessment. The literature search was performed using PubMed, Scopus, and Web of Science from January 1970 to March 2023. Eligible studies have investigated issues of interest to forensic medicine about traffic accidents involving bicycles. A total of 128 studies satisfied the inclusion criteria and were categorized and analyzed according to the anatomical regions of the body affected (head, neck, thoraco-abdominal, and limb injuries), and the assessment of lesions in reconstruction of the bicycle accident was examined and discussed. This review highlights that injuries resulting from a traffic accident involving cyclists can show distinct and specific characteristics depending on the manner of occurrence and the energy levels involved in the crash. The assessment of injuries offers valuable insights that integrated with circumstantial and engineering data perform the reconstruction of accident dynamics.

A Review of Cyclist Head Injury, Impact Characteristics and the Implications for Helmet Assessment Methods

Head injuries are common for cyclists involved in collisions. Such collision scenarios result in a range of injuries, with different head impact speeds, angles, locations, or surfaces. A clear understanding of these collision characteristics is vital to design high fidelity test methods for evaluating the performance of helmets. We review literature detailing real-world cyclist collision scenarios and report on these key characteristics. Our review shows that helmeted cyclists have a considerable reduction in skull fracture and focal brain pathologies compared to non-helmeted cyclists, as well as a reduction in all brain pathologies. The considerable reduction in focal head pathologies is likely to be due to helmet standards mandating thresholds of linear acceleration. The less considerable reduction in diffuse brain injuries is likely to be due to the lack of monitoring head rotation in test methods. We performed a novel meta-analysis of the location of 1809 head impacts from ten studies. Most studies showed that the side and front regions are frequently impacted, with one large, contemporary study highlighting a high proportion of occipital impacts. Helmets frequently had impact locations low down near the rim line. The face is not well protected by most conventional bicycle helmets. Several papers determine head impact speed and angle from in-depth reconstructions and computer simulations. They report head impact speeds from 5 to 16 m/s, with a concentration around 5 to 8 m/s and higher speeds when there was another vehicle involved in the collision. Reported angles range from 10° to 80° to the normal, and are concentrated around 30°-50°. Our review also shows that in nearly 80% of the cases, the head impact is reported to be against a flat surface. This review highlights current gaps in data, and calls for more research and data to better inform improvements in testing methods of standards and rating schemes and raise helmet safety.

Impact of wearing a helmet on the risk of hospitalization and intracranial haemorrhage after a sports injury

BACKGROUND

Despite their reported protective effect against the occurrence of head injuries, helmets are still used inconsistently in sports in which they are optional. We aimed to assess the impact of helmet use on the risk of hospitalization and intracranial haemorrhage for trauma occurring during sport activities.

METHODS

Retrospective cohort of all patients who presented themselves, over an 18-month period, at the emergency department of a tertiary trauma centre for an injury sustained in a sport or leisure activity where the use of a helmet is optional. Impact of helmet use was assessed using multivariable regression analyses (relative risks, RR).

RESULTS

Among the 1,022 patients included in the study, half were cyclists and 40% were skiers or snowboarders. A total of 40 % of patients wore a helmet at the time of injury, 18% had a head injury, 16% were hospitalized and 13% of patients with a head injury had an intracranial haemorrhage. Among all patients, no association was observed between hospital admission and helmet use. However, helmet use in patients with a head injury was associated with significant reductions in the risks of hospitalization (RR 0.41 [95% CI: 0.22-0.76]) and intracranial haemorrhage (RR 0.28 [95% CI: 0.11-0.71]).

CONCLUSIONS

Results suggest that, in recreational athletes who sustain a head injury, helmet use is associated with a reduced risk of hospitalization (all sports) and intracranial haemorrhage (cyclists).