Effectiveness of bicycle helmets in preventing head injury in children: case-control study.

OBJECTIVE--To examine the risk of injury to the head and the effect of wearing helmets in bicycle accidents among children. DESIGN--Case-control study by questionnaire completed by the children and their carers. SETTING--Two large children''s hospitals in Brisbane, Australia. SUBJECT--445 children presenting with bicycle related injuries during 15 April 1991 to 30 June 1992. The cases comprised 102 children who had sustained injury to the upper head including the skull, forehead and scalp or loss of consciousness. The controls were 278 cyclists presenting with injuries other than to the head or face. A further 65 children with injuries to the face were considered as an extra comparison group. MAIN OUTCOME MEASURES--Cause and type of injury, wearing of helmet. RESULTS--Most children (230) were injured after losing control and falling from their bicycle. Only 31 had contact with another moving vehicle. Children with head injury were significantly more likely to have made contact with a moving vehicle than control children (19 (19%) v 12 (4%), P < 0.001). Head injuries were more likely to occur on paved surfaces than on grass, gravel, or dirt. Wearing a helmet reduced the risk of head injury by 63% (95% confidence interval 34% to 80%) and of loss of consciousness by 86% (62% to 95%). CONCLUSIONS--The risk of head injury in bicycle accidents is reduced among children wearing a helmet. Current helmet design maximises protection in the type of accident most commonly occurring in this study. Legislation enforcing helmet use among children should be considered.     

Injury patterns in cyclists attending an accident and emergency department: a comparison of helmet wearers and non-wearers.

OBJECTIVES--To study circumstances of bicycle accidents and nature of injuries sustained and to determine effect of safety helmets on pattern of injuries. DESIGN--Prospective study of patients with cycle related injuries. SETTING--Accident and emergency department of teaching hospital. SUBJECTS--1040 patients with complete data presenting to the department in one year with cycle related injuries, of whom 114 had worn cycle helmets when accident occurred. MAIN OUTCOME MEASURES--Type of accident and nature and distribution of injuries among patients with and without safety helmets. RESULTS--There were no significant differences between the two groups with respect to type of accident or nature and distribution of injuries other than those to the head. Head injury was sustained by 4/114 (4%) of helmet wearers compared with 100/928 (11%) of non-wearers (P = 0.023). Significantly more children wore helmets (50/309 (16%)) than did adults (64/731 (9%)) (P < 0.001). The incidence of head injuries sustained in accidents involving motor vehicles (52/288 (18%)) was significantly higher than in those not involving motor vehicles (52/754 (7%)) (chi 2 = 28.9, P < 0.0001). Multiple logistic regression analysis of probability of sustaining a head injury showed that only two variables were significant: helmet use and involvement of a motor vehicle. Mutually adjusted odds ratios showed a risk factor of 2.95 (95% confidence interval 1.95 to 4.47, P < 0.0001) for accidents involving a motor vehicle and a protective factor of 3.25 (1.17 to 9.06, P = 0.024) for wearing a helmet. CONCLUSION--The findings suggest an increased risk of sustaining head injury in a bicycle accident when a motor vehicle is involved and confirm protective effect of helmet wearing for any bicycle accident.     

Effectiveness of helmets in skiers and snowboarders: case-control and case crossover study

Objective To determine the effect of helmets on the risk of head and neck injuries in skiers and snowboarders.Design Matched case-control and case crossover study.Setting 19 ski areas in Quebec, Canada, November 2001 to April 2002.Participants 1082 skiers and snowboarders (cases) with head and neck injuries reported by the ski patrol and 3295 skiers and snowboarders (controls) with non-head or non-neck injuries matched to cases at each hill.Main outcome measures Estimates of matched odds ratios for the effect of helmet use on the risk of any head or neck injury and for people requiring evacuation by ambulance.Results The adjusted odds ratio for helmet use in participants with any head injury was 0.71 (95% confidence interval 0.55 to 0.92), indicating a 29% reduction in the risk of head injury. For participants who required evacuation by ambulance for head injuries, the adjusted odds ratio for helmet use was 0.44 (0.24 to 0.81). Similar results occurred with the case crossover design (odds ratio 0.43, 0.09 to 1.83). The adjusted odds ratio for helmet use for participants with any neck injury was 0.62 (0.33 to 1.19) and for participants who required evacuation by ambulance for neck injuries it was 1.29 (0.41 to 4.04).Conclusions Helmets protect skiers and snowboarders against head injuries. We cannot rule out the possibility of an increased risk of neck injury with helmet use, but the estimates on which this assumption is based are imprecise.     

Differences in outcomes of mandatory motorcycle helmet legislation by country income level: A systematic review and meta-analysis

BackgroundThe recent Lancet Commission on Legal Determinants of Global Health argues that governance can provide the framework for achieving sustainable development goals. Even though over 90% of fatal road traffic injuries occur in low- and middle-income countries (LMICs) primarily affecting motorcyclists, the utility of helmet laws outside of high-income settings has not been well characterized. We sought to evaluate the differences in outcomes of mandatory motorcycle helmet legislation and determine whether these varied across country income levels.Methods and findingsA systematic review and meta-analysis were completed using the PRISMA checklist. A search for relevant articles was conducted using the PubMed, Embase, and Web of Science databases from January 1, 1990 to August 8, 2021. Studies were included if they evaluated helmet usage, mortality from motorcycle crash, or traumatic brain injury (TBI) incidence, with and without enactment of a mandatory helmet law as the intervention. The Newcastle–Ottawa Scale (NOS) was used to rate study quality and funnel plots, and Begg’s and Egger’s tests were used to assess for small study bias. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were stratified by high-income countries (HICs) versus LMICs using the random-effects model. Twenty-five articles were included in the final analysis encompassing a total study population of 31,949,418 people. There were 17 retrospective cohort studies, 2 prospective cohort studies, 1 case–control study, and 5 pre–post design studies. There were 16 studies from HICs and 9 from LMICs. The median NOS score was 6 with a range of 4 to 9. All studies demonstrated higher odds of helmet usage after implementation of helmet law; however, the results were statistically significantly greater in HICs (OR: 53.5; 95% CI: 28.4; 100.7) than in LMICs (OR: 4.82; 95% CI: 3.58; 6.49), p-value comparing both strata < 0.0001. There were significantly lower odds of motorcycle fatalities after enactment of helmet legislation (OR: 0.71; 95% CI: 0.61; 0.83) with no significant difference by income classification, p-value: 0.27. Odds of TBI were statistically significantly lower in HICs (OR: 0.61, 95% CI 0.54 to 0.69) than in LMICs (0.79, 95% CI 0.72 to 0.86) after enactment of law (p-value: 0.0001). Limitations of this study include variability in the methodologies and data sources in the studies included in the meta-analysis as well as the lack of available literature from the lowest income countries or from the African WHO region, in which helmet laws are least commonly present.ConclusionsIn this study, we observed that mandatory helmet laws had substantial public health benefits in all income contexts, but some outcomes were diminished in LMIC settings where additional measures such as public education and law enforcement might play critical roles.

In a systematic review and meta-analysis, Jacob Lepard and colleagues evaluate the differences in outcomes of mandatory motorcycle helmet legislation by country-income level.     

Investigating helmet promotion for cyclists: results from a randomised study with observation of behaviour, using a semi-automatic video system

Introduction

Half of fatal injuries among bicyclists are head injuries. While helmet use is likely to provide protection, their use often remains rare. We assessed the influence of strategies for promotion of helmet use with direct observation of behaviour by a semi-automatic video system.

Methods

We performed a single-centre randomised controlled study, with 4 balanced randomisation groups. Participants were non-helmet users, aged 18–75 years, recruited at a loan facility in the city of Bordeaux, France. After completing a questionnaire investigating their attitudes towards road safety and helmet use, participants were randomly assigned to three groups with the provision of “helmet only”, “helmet and information” or “information only”, and to a fourth control group. Bikes were labelled with a colour code designed to enable observation of helmet use by participants while cycling, using a 7-spot semi-automatic video system located in the city. A total of 1557 participants were included in the study.

Results

Between October 15th 2009 and September 28th 2010, 2621 cyclists'' movements, made by 587 participants, were captured by the video system. Participants seen at least once with a helmet amounted to 6.6% of all observed participants, with higher rates in the two groups that received a helmet at baseline. The likelihood of observed helmet use was significantly increased among participants of the “helmet only” group (OR = 7.73 [2.09–28.5]) and this impact faded within six months following the intervention. No effect of information delivery was found.

Conclusion

Providing a helmet may be of value, but will not be sufficient to achieve high rates of helmet wearing among adult cyclists. Integrated and repeated prevention programmes will be needed, including free provision of helmets, but also information on the protective effect of helmets and strategies to increase peer and parental pressure.     

Nonuse of bicycle helmets and risk of fatal head injury: a proportional mortality, case�Ccontrol study

Background:

The effectiveness of helmets at preventing cycling fatalities, a leading cause of death among young adults worldwide, is controversial, and safety regulations for cycling vary by jurisdiction. We sought to determine whether nonuse of helmets is associated with an increased risk of fatal head injury.

Methods:

We used a case–control design involving 129 fatalities using data from a coroner’s review of cycling deaths in Ontario, Canada, between 2006 and 2010. We defined cases as cyclists who died as a result of head injuries; we defined controls as cyclists who died as a result of other injuries. The exposure variable was nonuse of a bicycle helmet.

Results:

Not wearing a helmet while cycling was associated with an increased risk of dying as a result of sustaining a head injury (adjusted odds ratio [OR] 3.1, 95% confidence interval [CI] 1.3–7.3). We saw the same relationship when we excluded people younger than 18 years from the analysis (adjusted OR 3.5, 95% CI 1.4–8.5) and when we used a more stringent case definition (i.e., only a head injury with no other substantial injuries; adjusted OR 3.6, 95% CI 1.2–10.2).

Interpretation:

Not wearing a helmet while cycling is associated with an increased risk of sustaining a fatal head injury. Policy changes and educational programs that increase the use of helmets while cycling may prevent deaths.One cyclist dies in Canada each week, and cycling fatalities account for more than 2% of traffic fatalities, a leading cause of death in young adults.¹ Cycling safety regulations vary by jurisdiction, and controversy remains about the effectiveness of safety measures such as helmets. There is strong evidence that helmets prevent nonfatal head injuries,² but very limited evidence exists related to fatal head injuries. A meta-analysis of case–control studies showed a protective effect of helmets against head injuries, but it was based on just 4 case fatalities in which helmets were not worn.³ Another large study involving 1710 cycling collisions found a trend toward a protective effect of helmets, but included only 14 fatalities.⁴ The existing literature leaves open the possibility that helmets prevent nonfatal head injuries, but not fatal ones.We sought to determine whether cycling without a helmet was associated with an increased risk of sustaining a fatal head injury.     

Head injury in facial impact--a finite element analysis of helmet chin bar performance

The chin bar of a motorcycle helmet protects the rider from facial and head injuries. To evaluate the protective performance of chin bars against head injuries from facial impacts, an explicit finite element method was used to simulate the Snell Memorial Foundation test and a proposed drop test. The maximum acceleration and Head Injury Criterion (HIC) were employed to assess the impact-absorbing capability of the chin bar. The results showed that the proposed approach should be more practical than the Snell test, and provided more information for improving the chin bar design to protect against head injuries. The shell stiffness was important in determining the protective ability of the chin bar, but a chin bar with only an outer shell and comfort foam offered inadequate protection. An energy-absorbing liner was essential to increase the protective performance of the chin bar and the liner density should be denser than that used in the cranial portion of the helmet. For the chin bar with energy-absorbing liner, a shell design that is less stiff would provide better protection.     

Bicycle-related injuries: a survey in a pediatric emergency department.

The number of bicycle-related injuries has risen significantly with the increased popularity of bicycle riding in Canada. The risk of injury is highest among children. To assess the magnitude of the problem and to identify the contributing factors we used a questionnaire, injury reports and patient charts to survey bicycle-related injuries among children brought to the emergency department of the Children''s Hospital of Eastern Ontario, Ottawa, between May 1 and Sept. 30, 1988. The questionnaire was completed for 517 (91%) of the 568 children; 70% were boys, and the mean age was 9.4 years. Only 2% of the patients had been wearing a helmet at the time of injury, although 13% claimed to own one for cycling. Over 60% of the accidents were attributable to carelessness or poor bicycle control; mechanical failure and environmental hazards were minor factors. Over 80% of the injuries occurred within a kilometre of the child''s home. Of the 97 children admitted to hospital 49% had head and skull injuries and 40% had limb fractures. Bicycle-related injuries represented 14.8% of all nonwinter (Apr. 1 to Oct. 31) trauma admissions among children 5 years or older. Our results further document bicycle-related injuries as an important childhood problem and underscore the need for improved safety measures.     

The Impact of the Thai Motorcycle Transition on Road Traffic Injury: Thai Cohort Study Results

Objectives

The aim of this study was to investigate the impact of motorcycle to car transitioning and urbanisation on traffic injury rates in Thailand.

Design

Analysis of two consecutive surveys of a large national cohort study.

Setting

Thailand.

Participants

The data derived from 57,154 Thai Cohort Study (TCS) participants who provided relevant data on both the 2005 and 2009 surveys.

Primary and secondary outcome measures

Motorcycle and car traffic crash injury self-reported in 2009, with twelve months’ recall.

Results

In 2009, 5608(10%) participants reported a traffic crash injury. Most crashes involved a motorcycle (74%). Car access increased and motorcycle use decreased between 2005 and 2009. Among those who used a motorcycle at both time points, traffic injury incidence was 2.8 times greater compared to those who did not use a motorcycle at either time point. Multivariable logistic regression models were used to test longitudinal and cross sectional factors associated with traffic crash injury: in the adjusted model, cars were negatively and motorcycles positively associated with injury. Living in an urban area was not injury protective in the adjusted model of traffic crash injury.

Conclusions

Ongoing urbanisation in Thailand can be expected to lead to further reductions in road traffic injuries based on transition from motorcycles to cars in urban areas. Cities, however, do not provide an intrinsically safer traffic environment. To accommodate a safe transition to car use in Thailand, traffic infrastructural changes anticipating the growing car density in urban areas is warranted.     

Pediatric and Youth Traffic-Collision Injuries in Al Ain,United Arab Emirates: A Prospective Study

Aim

To study the mechanism of road traffic collisions (RTC), use of safety devices, and outcome of hospitalized pediatric and youth RTC injured patients so as to give recommendations regarding prevention of pediatric RTC injuries.

Methods

All RTC injured children and youth (0–19-year-olds) who were admitted to Al Ain City’s two major trauma centers or who died after arrival to these centers were prospectively studied from April 2006 to October 2007. Demography of patients, road-user and vehicle types, crash mechanism, usage of safety devices, injured body regions, injury severity, Revised Trauma Score, Glasgow Coma Scale, intensive care unit admissions, hospital stay and mortality were analyzed.

Results

245 patients were studied, 69% were vehicle occupants, 15% pedestrians, 9% motorcyclists and 5% bicyclists. 79% were males and 67% UAE citizens. The most common mechanism of RTC was rollover of vehicle (37%) followed by front impact collision (32%). 32 (13%) of vehicle occupants were ejected from car. 63% of ejected occupants and 70% of motorcyclists sustained head injuries. Only 2% (3/170) vehicle passengers used seatbelts and 13% (3/23) motorcyclists a helmet.

Conclusions

Male drivers and UAE nationals were at high risk of RTC as drivers and as motorcyclists. Ejection rate was high because safety restraint use was extremely low in our community. More education and law enforcement focusing especially on car/booster seat use is needed.     

Simulation-based assessment for construction helmets

In recent years, there has been a concerted effort for greater job safety in all industries. Personnel protective equipment (PPE) has been developed to help mitigate the risk of injury to humans that might be exposed to hazardous situations. The human head is the most vulnerable to impact as a moderate magnitude can cause serious injury or death. That is why industries have required the use of an industrial hard hat or helmet. There have only been a few articles published to date that are focused on the risk of head injury when wearing an industrial helmet. A full understanding of the effectiveness of construction helmets on reducing injury is lacking. This paper presents a simulation-based method to determine the threshold at which a human will sustain injury when wearing a construction helmet and assesses the risk of injury for wearers of construction helmets or hard hats. Advanced finite element, or FE, models were developed to study the impact on construction helmets. The FE model consists of two parts: the helmet and the human models. The human model consists of a brain, enclosed by a skull and an outer layer of skin. The level and probability of injury to the head was determined using both the head injury criterion (HIC) and tolerance limits set by Deck and Willinger. The HIC has been widely used to assess the likelihood of head injury in vehicles. The tolerance levels proposed by Deck and Willinger are more suited for finite element models but lack wide-scale validation. Different cases of impact were studied using LSTC's LS-DYNA.     

The effects of topology and relative density of lattice liners on traumatic brain injury mitigation

This paper evaluates the effects of topology and relative density of helmet lattice liners on mitigating Traumatic Brain Injury (TBI). Finite Element (FE) models of new lattice liners with prismatic and tetrahedral topologies were developed. A typical frontal head impact in motorcycle accidents was simulated, and linear and rotational accelerations of the head were recorded. A high-fidelity FE model of TBI was loaded with the accelerations to predict the brain response during the accident. The results show that prismatic lattices have better performance in preventing TBI than tetrahedral lattices and EPS that is typically used in helmets. Moreover, varying the cell size through the thickness of the liner improves its performance, but this effect was marginal. The relative density also has a significant effect, with lattices with lower relative densities providing better protection. Across different lattices studied here, the prismatic lattice with a relative density of 6% had the best performance and reduced the peak linear and rotational accelerations, Head Injury Criterion (HIC), brain strain and strain rate by 48%, 37%, 49%, 32% and 65% respectively, compared to the EPS liner. These results can be used to guide the design of lattice helmet liners for better mitigation of TBI.     

Eye injuries in squash: a preventable disease.

As more Canadians are taking up squash the incidence of eye injuries is increasing dramatically. Over 2-1/2 years, 23 cases from one urban practice were examined. Almost half of the group required inhospital treatment. Five patients sustained a permanent decrease in vision; these cases involved three corneal scars, one cataract and one macular cyst. Patients wearing glasses or hard contact lenses appear to be more susceptible to serious eye injury. Experience does not appear to reduce the likelihood of eye injuries; the patients in this study had played squash for 5.6 years on the average. Consequently the medical profession must take the lead by encouraging squash players to use protective equipment now available to reduce the incidence of these injuries that pose so much personal hazard.     

Rebreathing in a subject wearing an integral crash helmet.

The respired air of a volunteer was analysed while he was wearing a variety of integral crash helmets. Observations were made with and without a protective balaclava, bib or scarf, or both. Rebreathing occurred and the peak inspired oxygen tension fell as low as 16.0 kPa (120 mm Hg) with a minimum inspired carbon dioxide of 2.1 KPa (16.0 mm Hg). Accessories worn or attached to the helmet which restrict airflow into the helmet should not be used. Attention should be paid to the "air conditioning" of helmets when worn with flameproof balaclavas and bibs.     

Effect of alternating G loads on the activities of a human operator wearing a protective helmet

Specific types of operator activity make it necessary to wear a helmet protecting the head against various physical factors. Wearing a heavy helmet for a long time may affect the quality of operator activity when the operator is exposed to alternating G loads. Studies have been performed using a dynamic model of a vehicle subjected to considerable alternating G loads. Crash test dummies have been used to test a system protecting the cervical region of the spinal column. The effects of accelerations, vibrations, and the time of wearing helmets with different weights on the functional state and operator performance have been studied. Data on the effects of helmet weight on some physiological, psychological, and biomechanical reactions of human operators are reported. Some relationships have been found that have practical implications for the functional improvement of the operator component of vehicle operation.     

Factors Associated with Injuries among Commercial Motorcyclists: Evidence from a Matched Case Control Study in Kampala City,Uganda

Introduction

Road traffic injuries are the eighth leading cause of death globally and the most affected are young people aged 15–29. By 2030 road traffic deaths will become the fifth leading cause of death unless urgent action is taken. Motorcyclists are among the most vulnerable road users and in Uganda they contribute 41% of all road traffic injuries. This paper establishes factors associated with the injuries of commercial motorcycle riders also known as boda-boda riders in Kampala, Uganda’s capital city.

Methods

The study was matched case-control with a case being a boda-boda rider that was seen at one of the 5 major city hospitals with a road traffic injury while a control was a boda-boda rider that was at the parking stage where the case operated from before the injury. The sample size was 289 riders per arm and data collection took 7 months. A structured questionnaire was used to collect data on background and exposing factors. Being matched case-control data conditional logistic regression was used in the analysis.

Results

Factors independently associated with injury among motorcyclists were younger age group, being a current alcohol drinker (OR = 2.30, 95%CI: 1.19–4.45), lower engine capacity (<100cc)(OR = 5.03, 95%CI: 2.91–8.70), riding experience of less than 3 years, not changing a motorcycle in past 1 year (OR = 2.04, 95%CI: 1.19–3.52), riding for a longer time in a day (OR = 6.05, 95%CI: 2.58–14.18) and sharing a motorcycle (OR = 8.25, 95%CI:2.62–25.9). Other factors associated with injury were low level of knowledge of traffic rules, being stopped by police for checks on condition of motorcycle/license/insurance, working till late.

Recommendations

More road safety sensitization is required among riders to raise awareness against sharing motorcycles, working for a longer time and alcohol consumption. Police enforcement of drink-driving laws should include riders of commercial motorcycles. Investigate the validity of motorcycle riding licenses and test the riding competency of all who got licenses in last 3 years.     

Non-fatal injuries sustained by seatbelt wearers: a comparative study.

The injuries sustained by 969 drivers and front-seat passengers in road-traffic accidents were studied. Altogether 196 (20-2%) of the drivers and passengers were wearing seat belts and 773 (79-8%) were not. The injuries among the two groups differed greatly in both severity and distribution. A total of 54 (27-6%) of the seatbelt wearers sustained one or more fractures compared with 300 (38-8%) of the non-wearers, and 18 (9-2%) of the seatbelt wearers were severely injured compared with 300 (38-8%) of the non-wearers. Soft-tissue injuries to the face were sustained by only 29 (14-8%) of the seatbelt wearers compared with 425 (55%) of the non-wearers. Since wearing seatbelts may become compulsory, the type and pattern of injuries to be expected in wearers should be appreciated.     

Finite element analysis for the evaluation of protective functions of helmets against ballistic impact

The ballistic impact of a human head model protected by a Personnel Armor System Ground Troops Kevlar^® helmet is analysed using the finite element method. The emphasis is to examine the effect of the interior cushioning system as a shock absorber in mitigating ballistic impact to the head. The simulations of the frontal and side impacts of the full metal jacket (FMJ) and fragment-simulating projectile (FSP) were carried out using LS-DYNA. It was found that the Kevlar^® helmet with its interior nylon and leather strap was able to defeat both the FMJ and FSP without the projectiles penetrating the helmet. However, the head injuries caused by the FMJ impact can be fatal due to the high stiffness of the interior strap. The bulge section at the side of the Kevlar^® helmet had more room for deformation that resulted in less serious head injuries.