Pogo-Sticks and Maxillofacial Injuries: A Review of 619 Head and Neck Injuries

PURPOSE

The purpose of this study is to explore head and neck injuries secondary to accidents involving pogo sticks.

MATERIALS AND METHODS

We conducted a 20-year cross-sectional study using the National Electronic Injury Submission System (NEISS). Head and neck injuries resulting from the use of a pogo-stick were included. The predictor variables were demographics, type, site, context of injury, and season in which the injury occurred. The primary outcome variable was admission rate, used to estimate the severity of the injury. We employed chi-squared and independent sample tests to determine whether an association existed or not. We conducted a multivariate logistic regression model to determine the odds of admission for all significant variables.

RESULTS

A total of 619 pogo stick injuries were included, with 96.1% under 18 years of age. The decrease in the number of injuries from the year 2000 to 2019 was significant (P = .003). Nearly all patients were under 18 (96.1%), with the remaining few being 18 or older. Laceration (43.8%) was the most common primary diagnosis. The head (37.2%) was the most commonly injured anatomical region, followed by the face (32.8%). The majority of the injuries took place at the patient's home (85.9%). Patients with head injuries were more likely to be admitted relative to patients who didn't suffer head injuries (P < .01). Concerning primary diagnosis, patients who suffered fractures and internal organ injuries were more likely to be admitted relative to patients without the respective injuries (P < .01). On the contrary, patients who suffered lacerations were less likely to be admitted than patients who did not suffer lacerations (P < .01). After controlling for all possible covariates, fracture (OR, 12.31; P < .01) was independently associated with increased odds of admission. Additionally, compared to all other injuries, fractures were roughly 21 times (P < .05) more likely to get admitted. Patients under 18 were less likely to suffer an internal organ injury relative to patients age 18 or older (P < .05).

CONCLUSIONS

Head and neck injuries secondary to pogo sticks illustrated a predilection to the head. Fractures were the culprit behind the significantly increased odds of admission. Hence, all sectors of society should conceive different measures and implement them to protect against skull fractures (ie, helmet). Despite the decline in popularity of pogo sticks over the last two decades, all remaining riders should wear a helmet as religiously as bicycles or scooter riders to protect against skull fractures.

Intoxication is a Significant Risk Factor for Severe Craniomaxillofacial Injuries in Standing Electric Scooter Accidents

PURPOSE

Standing electric scooters are a relatively new mode of transportation that are becoming increasingly popular in large metropolitan areas. The purpose of this study was to characterize injury patterns and identify risk factors for craniomaxillofacial injuries in standing electric scooter accidents.

METHODS

This retrospective cohort study used a Clinical Data Warehouse search engine to identify patients who sustained standing electric scooter accidents from 2017 to 2019 using the International Classification of Diseases 10th revision codes. Predictors including patient demographics, presence of intoxication, helmet use, mechanism of injury, and other noncraniomaxillofacial injuries sustained at the time of standing electric scooter injury were identified. Patients were grouped as per the presence or absence of craniomaxillofacial injuries so that risk factors could be identified for craniomaxillofacial injuries in standing electric scooter accidents. Logistic regression analysis was performed to identify potential risk factors and association for craniomaxillofacial injuries.

RESULTS

The sample was composed of 165 patients with a mean age of 30.3 years and 73.9% were men. Of them, 38 (23.0%) sustained craniomaxillofacial trauma. They were ten times more likely to have been intoxicated than those who did not have craniomaxillofacial injuries (4.7 vs 52.6%). Concomitant injuries of the extremities and the craniomaxillofacial region were rare indicating that in many cases the arms and legs were not outstretched to "break the fall." The high numbers of mandibular fractures to the condylar, subcondylar, and symphyseal regions (23.8, 33.3, and 28.6%, respectively), Le Fort fractures (18.4%), and frontal sinus fractures (15.8%) indicate that falls in the anterior-posterior direction occur with the main point of impact occurring at the chin, midface, and forehead.

CONCLUSIONS

Intoxication may inhibit or depress protective reflexes that leave the face and head vulnerable during standing electric scooter accidents.

The effectiveness of different types of motorcycle helmets - A scoping review

BACKGROUND

Protective helmets may reduce the risk of death and head injury in motorcycle collisions. However, there remains a large gap in knowledge regarding the effectiveness of different types of helmets in preventing injuries.

OBJECTIVE

To explore and evaluate the effectiveness of different types of motorcycle helmets; that is the association between different helmet types and the incidence and severity of head, neck, and facial injuries among motorcyclists. Also, to explore the effect of different helmet types on riders.

METHODS

A systematic search of different scientific databases was conducted from 1965 to April 2019. A scoping review was performed on the included articles. Eligible articles were included regarding defined criteria. Study characteristics, helmet types, fixation status, retention system, the prevention of injury or reduction of its severity were extracted.

RESULTS

A total of 137 studies were included. There was very limited evidence for the better protection of full-face helmets from head and facial injury compared to open-face and half-coverage helmets. There was however scarce evidence for the superiority of a certain helmet type over others in terms of protection from neck injury. The retention system and the fixation status of helmets were two important factors affecting the risk of head and brain injury in motorcyclists. Helmets could also affect and limit the riders in terms of vision, hearing, and ventilation. Multiple solutions have been discussed to mitigate these effects.

CONCLUSION

Full-face helmets may protect head and face in motorcycle riders more than open-face and half-coverage helmets, but there is not enough evidence for better neck protection among these three helmet types. Helmets can affect the rider's vision, hearing, and ventilation. When designing a helmet, all of these factors should be taken into account.

Potential of Soft-Shelled Rugby Headgear to Reduce Linear Impact Accelerations

The purpose of this study was to examine the potential of soft-shelled rugby headgear to reduce linear impact accelerations. A hybrid III head form instrumented with a 3-axis accelerometer was used to assess headgear performance on a drop test rig. Six headgear units were examined in this study: Canterbury Clothing Company (CCC) Ventilator, Kukri, 2nd Skull, N-Pro, and two Gamebreaker headgear units of different sizes (headgears 1-6, respectively). Drop heights were 238, 300, 610, and 912 mm with 5 orientations at each height (forehead, front boss, rear, rear boss, and side). Impact severity was quantified using peak linear acceleration (PLA) and head injury criterion (HIC). All headgear was tested in comparison to a no headgear condition (for all heights). Compared to the no headgear condition, all headgear significantly reduced PLA and HIC at 238 mm (16.2-45.3% PLA and 29.2-62.7% HIC reduction; P < 0.0005, η p 2 = 0.987-0.991). Headgear impact attenuation lowered significantly as the drop height increased (32.4-5.6% PLA and 50.9-11.7% HIC reduction at 912 mm). There were no significant differences in PLA or HIC reduction between headgear units 1-3. Post hoc testing indicated that headgear units 4-6 significantly outperformed headgear units 1-3 and additionally headgear units 5 and 6 significantly outperformed headgear 4 (P < 0.05). The lowest reduction PLA and HIC was for impacts rear orientation for headgear units 1-4 (3.3 ± 3.6%-11 ± 5.8%). In contrast, headgear units 5 and 6 significantly outperformed all other headgear in this orientation (P < 0.0005, η p 2 = 0.982-0.990). Side impacts showed the greatest reduction in PLA and HIC for all headgear. All headgear units tested demonstrated some degree of reduction in PLA and HIC from a linear impact; however, units 4-6 performed significantly better than headgear units 1-3.

Night Vision Goggle and Counterweight Use Affect Neck Muscle Activity During Reciprocal Scanning

BACKGROUND: Mass, moment of inertia, and amplitude of neck motion were altered during a reciprocal scanning task to investigate how night vision goggles (NVGs) use mechanistically is associated with neck trouble among rotary-wing aircrew.METHODS: There were 30 subjects measured while scanning between targets at 2 amplitudes (near and far) and under 4 head supported mass conditions (combinations of helmet, NVGs, and counterweights). Electromyography (EMG) was measured bilaterally from the sternocleidomastoid and upper neck extensors. Kinematics were measured from the trunk and head.RESULTS: Scanning between the far amplitude targets required higher peak angular accelerations (7% increase) and neck EMG (between 1.24.5% increase), lower muscle cocontraction ratios (6.7% decrease), and fewer gaps in EMG (up to a 59% decrease) relative to the near targets. Increasing the mass of the helmet had modest effects on neck EMG, while increasing the moment of inertia did not.DISCUSSION: Target amplitude, not head supported mass configuration, had a greater effect on exposure metrics. Use of NVGs restricts field-of-view, requiring an increased amplitude of neck movement. This may play an important role in understanding links between neck trouble and NVG use.Healey LA, Derouin AJ, Callaghan JP, Cronin DS, Fischer SL. Night vision goggle and counterweight use affect neck muscle activity during reciprocal scanning. Aerosp Med Hum Perform. 2021; 92(3):172181.

Pediatric snow sport injuries differ by age

BACKGROUND

Unintentional injury is the leading cause of death among pediatric patients. There were 13,436 injuries related to snow sports in those younger than 15 in 2015, with 4.8% requiring admission. These sports are high-risk given the potential for injury even when using protective equipment. We hypothesized that snow sport injury patterns would differ based on patient age.

METHODS

A cross-sectional analysis of the 2009 and 2012 Kids' Inpatient Database was performed. Cases of injuries were identified and analyzed using ICD-9 codes. National estimates were obtained using case weighting. Multivariable logistic regression was used to assess for confounders.

RESULTS

Within 745 admissions, there was a statistically significant decrease in skull/facial fractures with increasing age and a statistically significant increase in abdominal injuries with increasing age. Children in early and middle childhood were at increased odds of being hospitalized with skull/facial fractures, while older children were more likely hospitalized with abdominal injuries.

CONCLUSIONS

Within the pediatric snow sport population, younger children are more likely to experience head injuries, while older children are more likely to experience abdominal injuries. Further research is needed to determine the origin of this difference, and continued legislation on helmets is also necessary in reducing intracranial injuries.

LEVEL OF EVIDENCE

III.

Comparing the risky behaviours of shared and private e-scooter and bicycle riders in downtown Brisbane, Australia

Electric scooter (e-scooter) use has increased internationally, with concerns about injuries to riders and pedestrians, and reports of non-use of helmets, excessive speed, drink-riding and underage riding. E-scooter regulations vary widely among jurisdictions, with likely effects on the extent and nature of safety issues. This study was conducted in downtown Brisbane, Australia, where e-scooters must be ridden on the footpath, bicycles are allowed on the road and the footpath, and helmet use is mandatory for bicycle and e-scooter riders of all ages. It examined involvement in illegal and risky behaviours, and interactions with pedestrians. Shared and private e-scooters, and shared and private bicycles were compared to assess the relative influences of type of vehicle and shared use. Observations at six sites in downtown Brisbane in February 2019 recorded 711 shared e-scooters, 90 private e-scooters, 274 shared bicycles and 2788 private bicycles. Illegal riding (not wearing a helmet, riding on the road, or carrying a passenger) was more prevalent among shared than private e-scooters (49.6 % vs. 12.2 %). Non-use of helmets was more common among riders of shared e-scooters (38.6 %, OR = 20.995, p < .001) and shared bicycles (18.8 %, OR = 10.994, p < .001) than private bicycles (1.5 %); occurred more often on the footpath than the road (20.1 % vs. 1.8 %, OR = 3.004, p < .001); and occurred more between 2 and 4 pm than between 7 and 9a.m. (21.3 % vs. 5.5 %, OR = 1.711, p < .01). More than 90 % of e-scooters, about half of shared bicycles and about a quarter of private bicycles were ridden on the footpath, with about 40 % within 1 m of at least one pedestrian. When there were pedestrians within 1 m, conflict rates ranged from zero to 1.5 % and no collisions were observed. At least for helmet non-use, the results suggest that risky behaviours are more prevalent among users of shared schemes, and that this difference is accentuated for e-scooters. Interactions with pedestrians are common but conflicts rarely occur in footpath riding. Further observational and survey studies are recommended to better understand the factors influencing the perceptions and behaviours of shared and private e-scooters and pedestrians. The knowledge gained from these studies needs to be integrated with injury outcome data to determine the appropriateness of rules for maximum speeds and locations of riding in terms of both rider and pedestrian safety.

A spatiotemporal analysis of motorcyclist injury severity: Findings from 20 years of crash data from Pennsylvania

Motorcyclists face higher risks of severe injuries in crashes compared to motor vehicle drivers who are often protected by seatbelts and airbags during collisions. A report by the National Highway Traffic Safety Administration reveals that motorcyclists have 27 times the risk of fatality in traffic crashes as much as motor vehicle drivers. Previous studies have identified a list of risk factors associated with motorcyclist injury severity and generated valuable insights for countermeasures to protect motorcyclists in crashes. These studies have shown that wearing helmets and/or motorcycle-specific reflective clothing and boots, driving alcohol/drug-free, and obeying traffic regulations are good practices for safe motorcycling. However, these practices and other risk factors are likely to interact with local geographic, socio-economic, and cultural contexts, leading to diversified correlations with motorcyclist injury severity, which remains under-explored. Such correlations may exhibit variations across space and time. The objective of this study is to revisit the correlates of motorcyclist injury severity with a focus on the spatial and temporal variations of correlations between risk factors and injury severity. This study employed an integrated spatiotemporal analytical approach to mine comprehensive statewide 20 years' motorcycle-involved traffic crashes (N = 50,823) in Pennsylvania. Non-stationarity tests were performed to examine the significance of variations in spatially and temporally local correlations. The results show that most factors, such as helmet, engine size, vehicle age, pillion passenger, at-fault striking, and speeding, hold significant non-stationary relationships with motorcyclist injury severity. Furthermore, cluster analysis of estimations reveals the regional similarities of correlates, which may help practitioners develop regional motorcyclist safety countermeasures.

Characteristics of injuries according to types of personal mobility devices in a multicenter emergency department from 2011 to 2017: A cross-sectional study

Personal mobility devices (PMDs) have emerged as new factors in motor vehicle accidents, and related injuries are increasing. We aimed to describe the characteristics of PMD-related injuries presented to emergency departments (EDs) through a cross-sectional study for 7 years.This study is a multicenter cross-sectional study using the Emergency Department-based Injury In-Depth Surveillance database in South Korea. We identified all PMD-related injuries from 2011 to 2017 based on text searching. We categorized them into 3 groups based on their distinguishable characteristics: electric standing scooter (E-scooter), electric self-balancing wheel (E-wheel), and electronic board (E-board).A total of 448 PMD-related injuries were observed during the observation period. E-scooter-, E-wheel-, and E-board-related injuries occurred in 284, 138, and 26 cases, respectively. Most patients were between the ages of 19 and 59 years (69.2%), men (66.3%), and injured because of leisure activity (61.2%). The mechanism of injury was mostly traffic accidents (75.2%), but regarding injuries involving E-wheel and E-board, 25.4% and 30.8% of patients slipped from the device. The most commonly injured body part was the head, which accounted for 58.1% of E-scooter injuries, 38.4% of E-wheel injuries, and 53.9% of E-board injuries. Only 6 of all patients wore a helmet at the time of accident.PMD users and PMD-sharing programs are increasing, and more accidents are expected in the future. As PMDs are convenient to move and more people are willing to use them, proper riding and safety rules based on the type of PMD are needed to reduce the risk of injury. The results of this study can be used as basic data for developing safety policies.

Helmet chinstrap protective role in maxillofacial blast injury

BACKGROUND

The protective role of helmet accessories in moderating stress load generated by explosion shock waves of explosive devices is usually neglected.

OBJECTIVE

In the presented study, the protective role of the helmet chinstrap against the impulse and overpressure experienced by the maxillofacial region were examined.

METHODS

The explosion shock wave and skull interaction were investigated under three different configurations: (1) unprotected skull, (2) skull with helmet (3) skull with helmet and chinstrap. For this purpose, a 3D finite element model (FEM) was constructed to mimic the investigated biomechanics module. Three working conditions were set according to different explosive charges and distances to represent different load conditions. Case 1: 500 mg explosive trinitrotoluene (TNT), 3 cm, case 2: 1000 mg TNT, 3 cm, and case 3: 1000 mg TNT and 6 cm distance to the studied object. The explosion effect was discussed by examining the shock wave stress flow pattern. Three points were selected on the skull and the stress curve of each point position were illustrated for each case study.

RESULTS

The results showed that the helmet chinstrap can reduce the explosive injuries and plays a protective role in the maxillofacial region, especially for the mandible.

Deriving functional safety (ISO 26262) S-parameters for vulnerable road users from national crash data

Currently, advanced driver assistance systems (ADAS) and automated vehicles (AV) are designed for use in the existing road infrastructure. These partially and fully automated vehicles will be operated in a shared space not only with other vehicles but also with vulnerable road users (VRU). Even though crashes between ADAS equipped vehicles or AV and VRU seem inevitable in such a scenario, functional safety, i.e., the assessment of the quality and safety level of the automation system, plays a crucial role in minimizing the crash frequency and the injury severity. We develop a data-driven approach to injury severity estimation for functional safety, i.e., ISO 26262 S-parameters, for four types of VRU: pedestrians, bicyclists, scooterists, and motorcycle riders. To estimate the S-parameter, the 90th-percentile of the injury severity distribution in the S-scale, a population-based data set (Germany's national data set DESTATIS) is used. Since the description of the injury severity in DESTATIS is not detailed enough for a direct one-to-one mapping to the S-scale, we enhance the level of detail in the population-based data set by using additional information from the German in-depth accident study (GIDAS), an in-depth, size-limited survey of part of the same population. Thus, we are able to transform the 4-level injury scale (uninjured, slightly injures, severely injured, and fatal) of the police reports found in DESTATIS into the three breakpoints of the injury severity scale (ISS) (ISS ≥{4, 9, 16}) which in turn directly translate to the four levels of the S-scale. Furthermore, the ISS ≥9 breakpoint more or less equates to MAIS 3+, the definition of 'severe injury' in nearly all international road safety goals that look beyond fatalities. The derived injury scale transformation can be utilized to translate the injury severities of the police-reported cases to the politically needed MAIS 3+ distribution. Thus, population-based data can be directly used to estimate the proportion of these 'severely injured.' The crashes are analyzed from the perspective of the VRU as well as from the vehicle type involved. We stratified the opposing vehicles by injury mechanism: wrap projection for bonnet type passenger vehicles (BTV), forward projection for box type vehicles like light trucks (LTV), as well as single-vehicle crashes. We cluster the crash data into traffic domains based on the speed limit: shared zone, residential streets, city roads, arterial thoroughfares, rural roads, and autobahn. For each VRU type, injury mechanism, and traffic domain, the S-parameters, i.e., the 90th-percentile of the injury severity measured in S-scale, are calculated with a one-sided 95% confidence level. Exemplary applications of the results are given in the discussion: an evaluation of an AV hitting a crossing pedestrian, an in-lane swerving ADAS system for VRU avoidance, and the rating of the nominal performance of an inflatable helmet for pedestrians.

Comparison of the clinical outcomes of non-invasive ventilation by helmet vs facemask in patients with acute respiratory distress syndrome

ABSTRACT

The main aim of this study is to compare the use of non-invasive ventilation (NIV) via helmet versus face mask where different interfaces and masks can apply NIV. However, some of the limitations of the NIV face mask were air leak, face mask intolerance, and requirement of high positive end expiratory pressure, which could be resolved with the use of the helmet NIV. NIV facemask will be applied as per the facial contour of the patient. NIV helmet is a transparent hood and size will be measured as per the head size. Both groups will have a standard protocol for titration of NIV.Patients aged more than 18 years old and diagnosed with acute respiratory distress syndrome as per Berlin definition will be enrolled in the study after signing the informed consent. Subjects who met the inclusion criteria will receive 1 of the 2 interventions; blood gases, oxygenation status [Po2/Fio2] will be monitored in both groups. The time of intubation will be the main comparison factor among the 2 groups. The primary and secondary outcomes will be measured by the number of patients requiring endotracheal intubation after application of helmet device, Improvement of oxygenation defined as PaO2/FiO2 ≥ 200 or increase from baseline by 100, duration of mechanical ventilation via an endotracheal tube, intensive care unit length of stay, death from any cause during hospitalization at the time of enrolment, need for proning during the hospital stay, intensive care unit mortality, and the degree to which overt adverse effects of a drug can be tolerated by a patient including feeding tolerance.

TRIAL REGISTRATION NUMBER

NCT04507802.

PROTOCOL VERSION

May 2020.

A New Assessment of Bicycle Helmets: The Brain Injury Mitigation Effects of New Technologies in Oblique Impacts

New helmet technologies have been developed to improve the mitigation of traumatic brain injury (TBI) in bicycle accidents. However, their effectiveness under oblique impacts, which produce more strains in the brain in comparison with vertical impacts adopted by helmet standards, is still unclear. Here we used a new method to assess the brain injury prevention effects of 27 bicycle helmets in oblique impacts, including helmets fitted with a friction-reducing layer (MIPS), a shearing pad (SPIN), a wavy cellular liner (WaveCel), an airbag helmet (Hövding) and a number of conventional helmets. We tested whether helmets fitted with the new technologies can provide better brain protection than conventional helmets. Each helmeted headform was dropped onto a 45° inclined anvil at 6.3 m/s at three locations, with each impact location producing a dominant head rotation about one anatomical axes of the head. A detailed computational model of TBI was used to determine strain distribution across the brain and in key anatomical regions, the corpus callosum and sulci. Our results show that, in comparison with conventional helmets, the majority of helmets incorporating new technologies significantly reduced peak rotational acceleration and velocity and maximal strain in corpus callosum and sulci. Only one helmet with MIPS significantly increased strain in the corpus collosum. The helmets fitted with MIPS and WaveCel were more effective in reducing strain in impacts producing sagittal rotations and a helmet fitted with SPIN in coronal rotations. The airbag helmet was effective in reducing brain strain in all impacts, however, peak rotational velocity and brain strain heavily depended on the analysis time. These results suggest that incorporating different impact locations in future oblique impact test methods and designing helmet technologies for the mitigation of head rotation in different planes are key to reducing brain injuries in bicycle accidents.

Aviation Maxillofacial Shields and Blunt Impact Protection in U.S. Army Helicopter Mishaps

BACKGROUND: Maxillofacial shields (MFSs) are an available piece of aviation protective equipment designed to integrate into aircrew helmets and protect the face from wind and flying debris. Aviators have anecdotally reported that MFSs have provided blunt impact protection during impact events (i.e., a crash); however, no such cases have been formally documented in the literature.CASE REPORTS: Two cases were identified where aircrew wearing MFSs were involved in mishaps resulting in maxillofacial blunt impacts. In the first case, an OH-58 pilot struck the cyclic with his head/face during a crash. In the second case, a CH-47 crew chief was struck in the face by a maintenance panel dislodged from the aircraft. In both cases the MFS was damaged, but neither service member experienced injuries as a result of impact to the face.DISCUSSION: The cases illustrate the effectiveness of the MFS against blunt impact during aviation mishaps. While MFS use is currently optional for aircrew, it is believed that increased MFS use would result in fewer or less severe facial injuries as well as decrease the associated time and monetary losses due to injury.Weisenbach CA, McGhee JS. Aviation maxillofacial shields and blunt impact protection in U.S. Army helicopter mishaps. Aerosp Med Hum Perform. 2021; 92(1):5053.

Impact Performance Comparison of Advanced Snow Sport Helmets with Dedicated Rotation-Damping Systems

Rotational acceleration of the head is a principal cause of concussion and traumatic brain injury. Several rotation-damping systems for helmets have been introduced to better protect the brain from rotational forces. But these systems have not been evaluated in snow sport helmets. This study investigated two snow sport helmets with different rotation-damping systems, termed MIPS and WaveCel, in comparison to a standard snow sport helmet without a rotation-damping system. Impact performance was evaluated by vertical drops of a helmeted Hybrid III head and neck onto an oblique anvil. Six impact conditions were tested, comprising two impact speeds of 4.8 and 6.2 m/s, and three impact locations. Helmet performance was quantified in terms of the linear and rotational kinematics, and the predicted probability of concussion. Both rotation-damping systems significantly reduced rotational acceleration under all six impact conditions compared to the standard helmet, but their effect on linear acceleration was less consistent. The highest probability of concussion for the standard helmet was 89%, while helmets with MIPS and WaveCel systems exhibited a maximal probability of concussion of 67 and 7%, respectively. In conclusion, rotation-damping systems of advanced snow sport helmets can significantly reduce rotational head acceleration and the associated concussion risk.

Incidence and severity of electric scooter related injuries after introduction of an urban rental programme in Vienna: a retrospective multicentre study

PURPOSE

Electric scooters (e-scooters) are an emerging way of mobility in cities around the world. Despite quickly rising numbers of e-scooters, limited studies report on incidence and severity of e-scooter-associated injuries. The aim of our study was to report on these injuries and identify potential protective measures to ultimately decrease e-scooter-associated morbidity.

METHODS

We performed a retrospective multicentre study including all patients, who were admitted to three major trauma departments in Vienna from May 2018 to September 2019. We analysed patients' data, including demographics, injury pattern, types of injury and subsequent treatment.

RESULTS

A total number of 175 patients (115 males, 60 females) sustained e-scooter-associated injuries. Patients' mean age was 34.4 years [4-74]. While the mean Injury Severity Score (ISS) was 3.4, 11 patients presented with an ISS ≥ 9 and 2 patients with an ISS ≥ 16. ISS increased with age. Older patients (≥ 40 years) presented a significantly higher ISS than younger patients (< 40 years) (P = 0.011). Seventy-one patients (40.6%) sustained major injuries affecting head (35.2%) and upper extremities (36.6%). Twenty-three patients (13.1%) required surgery leading to hospitalization of 11 days on average [1-115]. E-scooter-associated injuries increased during late afternoon plateauing at 8.00 pm. However, the largest share of patients (39.2%) sustained their injuries during early night (8.00 pm to 1.59 am) with especially young adults (19-39 years) being at risk.

CONCLUSION

The popularity of rideshare e-scooters across cities worldwide seems to be on the rise, so are e-scooter-associated injuries. These injuries should be considered high-energy trauma affecting primarily head and upper extremity; indeed, 17.7% sustained major head injuries. Therefore, the mandatory use of a helmet seems to be adequate to decrease head injury-associated morbidity. Ultimately, given the remarkably high rates of nighttime injuries, an e-scooter ban during night could further cut injury numbers in half.

A three-dimensional parametric adult head model with representation of scalp shape variability under hair

Modeling the shape of the scalp and face is essential for the design of protective helmets and other head-borne equipment. However, head anthropometry studies using optical scanning rarely capture scalp shape because of hair interference. Data on scalp shape is available from bald men, but female data are generally not available. To address this issue, scalp shape was digitized in an ethnically diverse sample of 100 adult women, age 18-59, under a protocol that included whole head surface scanning and scalp measurement using a three-dimensional (3D) coordinate digitizer. A combined male and female sample was created by adding 3D surface scans of a similarly diverse sample of 80 bald men. A statistical head shape model was created by standardizing the head scan data. A total of 58 anatomical head landmarks and 12 head dimensions were obtained from each scan and processed along with the scans. A parametric model accounting for the variability of the head shape under the hair as a function of selected head dimensions was developed. The full-variable model has a mean shape error of 3.8 mm; the 95th percentile error was 7.4 mm, which were measured at the vertices. The model will be particularly useful for generating a series of representing a target population as well as for generating subject-specific head shapes along with predicted landmarks and dimensions. The model is publicly available online at http://humanshape.org/head/.

Evaluation of the performance of replaceable particulate and powered air-purifying respirators considering non-recommended wearing methods

This study evaluated the performance of two respirators, a replaceable particulate respirator (RPR) and a powered air-purifying respirator (PAPR), worn according to non-recommended methods. Ten subjects wore either an RPR or PAPR according to the recommended method, or according to a non-recommended method, with a knit cover placed between the facepiece cushion and face, with a towel placed between the facepiece cushion and face, or with the headband on a helmet. The leakage rate of each wearing variation was then measured, according to the procedure for determining the protection factor of respiratory protective equipment, using atmospheric dust as required by JIS T8150. The average leakage rate for the RPR was 1.82-10.92%, whereas that of the PAPR was 0.18-0.42%. The performance of the RPR decreased when worn in methods outside of recommendations; however, there was no significant decrease in the performance of PAPR under any method of wear. Therefore, a PAPR is recommended for work in which a replaceable or disposable particulate respirator fails to provide sufficient protection against hazardous dust substances, or for workers who are unable to use a particulate respirator according to the recommended method owing to the work environment or health conditions.

Helmet continuous positive airway pressure versus high-flow nasal cannula in COVID-19: a pragmatic randomised clinical trial (COVID HELMET)

BACKGROUND

Patients with COVID-19 and hypoxaemia despite conventional low-flow oxygen therapy are often treated with high-flow nasal cannula (HFNC) in line with international guidelines. Oxygen delivery by helmet continuous positive airway pressure (CPAP) is a feasible option that enables a higher positive end-expiratory pressure (PEEP) and may theoretically reduce the need for intubation compared to HFNC but direct comparative evidence is lacking.

METHODS

We plan to perform an investigator-initiated, pragmatic, randomised trial at an intermediate-level COVID-19 cohort ward in Helsingborg Hospital, southern Sweden. We have estimated a required sample size of 120 patients randomised 1:1 to HFNC or Helmet CPAP to achieve 90% power to detect superiority at a 0.05 significance level regarding the primary outcome of ventilator free days (VFD) within 28 days using a Mann-Whitney U test. Patient recruitment is planned to being June 2020 and be completed in the first half of 2021.

DISCUSSION

We hypothesise that the use of Helmet CPAP will reduce the need for invasive mechanical ventilation compared to the use of HFNC without having a negative effect on survival. This could have important implications during the current COVID-19 epidemic.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04395807 . Registered on 20 May 2020.

The effect of the scalp on the effectiveness of bicycle helmets' anti-rotational acceleration technologies

OBJECTIVE

Medical data has lead to the common understanding that bicycle helmets need to be improved to better protect against brain injuries resulting from rotational acceleration. Although many different technologies exist for reducing rotational acceleration during impacts, the lack of an official testing standard means that their evaluation is based on customized set-ups that may differ and not represent real accident conditions. Previously, the authors have shown that scalp tissue plays an important role during helmet testing by absorbing energy and creating a low friction interface between head and helmet, thus reducing rotational accelerations and velocities. However, no published study has yet examined the effectiveness of anti-rotational helmet technologies in the presence of a biofidelic scalp layer. The objective of this study is to address this gap.

METHODS

Three different commercially available helmet models, each one equipped with a different technology, were tested in the presence of scalp tissue, in two different scenarios; with and without the technology present. The effectiveness of each of these technologies is already documented in other studies, but only in the absence of a biofidelic scalp layer. Tests were carried out using HIII headform with porcine scalp attached to the outmost layer. Motion tracking was used to compare the impact kinematics of each helmet model in both scenarios.

RESULTS

Results showed that when a biofidelic scalp layer is present, there is no statistical difference between helmet models with and without the anti-rotational technology in terms of rotational acceleration, velocity, relative rotation, impact duration and injury risk.

CONCLUSIONS

Results suggest that the presence of the scalp can obscure the functionality of anti-rotational acceleration technologies. This could indicate that the effectiveness of technologies tested in previous studies, which have not tested anti-rotational acceleration technologies in the presence of a realistic scalp layer, may exaggerate the contribution of such technologies if compared with a more biofidelic set-up. The study supports the fact that headforms should be better designed by incorporating artificial skin layers that can better imitate scalp's behavior and, in addition, provides insights for the design of technologies against rotational acceleration.

High Energy Side and Rear American Football Head Impacts Cause Obvious Performance Decrement on Video

The objective of this study was to compare head impact data acquired with an impact monitoring mouthguard (IMM) to the video-observed behavior of athletes' post-collision relative to their pre-collision behaviors. A total of n = 83 college and high school American football players wore the IMM and were video-recorded over 260 athlete-exposures. Ex-athletes and clinicians reviewed the video in a two-step process and categorized abnormal post-collision behaviors according to previously published Obvious Performance Decrement (OPD) definitions. Engineers qualitatively reviewed datasets to check head impact and non-head impact signal frequency and magnitude. The ex-athlete reviewers identified 2305 head impacts and 16 potential OPD impacts, 13 of which were separately categorized as Likely-OPD impacts by the clinical reviewers. All 13 Likely-OPD impacts were in the top 1% of impacts measured by the IMM (ranges 40-100 g, 3.3-7.0 m/s and 35-118 J) and 12 of the 13 impacts (92%) were to the side or rear of the head. These findings require confirmation in a larger data set before proposing any type of OPD impact magnitude or direction threshold exists. However, OPD cases in this study compare favorably with previously published impact monitoring studies in high school and college American football players that looked for OPD signs, impact magnitude and direction. Our OPD findings also compare well with NFL reconstruction studies for ranges of concussion and sub-concussive impact magnitudes in side/rear collisions, as well as prior theory, analytical models and empirical research that suggest a directional sensitivity to brain injury exists for single high-energy impacts.

Sensor orientation and other factors which increase the blast overpressure reporting errors

This study compared the response of the wearable sensors tested against the industry-standard pressure transducers at blast overpressure (BOP) levels typically experienced in training. We systematically evaluated the effects of the sensor orientation with respect to the direction of the incident shock wave and demonstrated how the averaging methods affect the reported pressure values. The evaluated methods included averaging peak overpressure and impulse of all four sensors mounted on a helmet, taking the average of the three sensors, or isolating the incident pressure equivalent using two sensors. The experimental procedures were conducted in controlled laboratory conditions using the shock tube, and some of the findings were verified in field conditions with live fire charges during explosive breaching training. We used four different orientations (0°, 90°, 180°, and 270°) of the headform retrofitted with commonly fielded helmets (ACH, ECH, Ops-Core) with four B3 Blast Gauge sensors. We determined that averaging the peak overpressure values overestimates the actual dosage experienced by operators, which is caused by the reflected pressure contribution. This conclusion is valid despite the identified limitation of the B3 gauges that consistently underreport the peak reflected overpressure, compared to the industry-standard sensors. We also noted consistent overestimation of the impulse. These findings demonstrate that extreme caution should be exercised when interpreting occupational blast exposure results without knowing the orientation of the sensors. Pure numerical values without the geometrical, training-regime specific information such as the position of the sensors, the distance and orientation of the trainee to the source of the blast wave, and weapon system used will inevitably lead to erroneous estimation of the individual and cumulative blast overpressure (BOP) dosages. Considering that the 4 psi (~28 kPa) incident BOP is currently accepted as the threshold exposure safety value, a misinterpretation of exposure level may lead to an inaccurate estimation of BOP at the minimum standoff distance (MSD), or exclusion criteria.

Effects of night-time bicycling visibility aids on vehicle passing distance

Bicycling at night is dangerous, with vehicle passing distances being a key concern, given that the main cause of night-time bicycling fatalities is from motorists hitting bicyclists from behind. However, little is known about vehicle passing distances at night or how they are affected by bicyclist visibility. This study assessed the impact of different bicyclist visibility configurations on vehicle passing distances at night-time. Fourteen licenced drivers with normal vision (age 24.2 ± 3.7 years) drove an experimental vehicle with low-beam headlights around a 1-km section of a closed-road circuit at night. Each lap involved passing two bicyclists displaying one of four visibility configurations: Control (red rear-facing light and reflector), Handlebars (control plus two red rear-facing lights on each handlebar), Helmet (control plus one red rear-facing light on the helmet), and Leg Retro-reflectors (control plus retro-reflective strips positioned on the knees and ankles). Participants were instructed to pass each bicyclist at a distance of 1-metre at a speed no greater than 50 km/hr, consistent with Queensland's Minimum Passing Distance rule. Participants completed eight laps, two for each configuration, in a randomised sequence. Passing distance was measured using a vehicle-mounted ultra-sonic sensor (ToughSonic14; Senix). Following each lap, participants rated the difficulty level in judging the 1-metre passing distance, as well as their estimated passing distance. Visibility configuration significantly affected passing distance (p = 0.001), with wider passing distances for the Handlebar configuration (1.54 ± 0.62 m), followed by the Helmet (1.51 ± 0.63 m), Leg Retro-reflectors (1.50 ± 0.62 m) which were all significantly greater than the Control (1.42 ± 0.57 m), but not significantly different from each other. There was also a significant effect of visibility configuration on difficulty rating (p = 0.035), with the Control rated as the most difficult, followed by Helmet, Handlebars and Leg Retro-reflectors. Overall, additional visibility aids resulted in wider vehicle passing distances, likely due to enhanced visual cues for drivers. The findings suggest that bicyclists should incorporate additional visibility aids to encourage safer passing distances of vehicles at night-time.

Subconcussive head impact exposure between drill intensities in U.S. high school football

USA Football established five levels-of-contact to guide the intensity of high school football practices. The objective of this study was to examine head impact frequency and magnitude by levels-of-contact to determine which drills had the greatest head impact exposure. Our primary hypothesis was that there would be an incremental increase in season-long head impact exposure between levels-of-contact: air<bags<control<thud<live. This observational study included 24 high-school football players during all 46 practices, 1 scrimmage, 9 junior varsity and 10 varsity games in the 2019 season. Players wore a sensor-installed mouthguard that monitored head impact frequency, peak linear acceleration (PLA), and rotational acceleration (PRA). Practice/game drills were filmed and categorized into five levels-of-contact (air, bags, control, thud, live), and head impact data were assigned into one of five levels-of-contact. Player position was categorized into lineman, hybrid, and skill. A total of 6016 head impacts were recorded during 5 levels-of-contact throughout the season. In the overall sample, total number of impacts, sum of PLA, and PRA per player increased in a near incremental manner (air<bags<control = thud<live), where live drills had significantly higher cumulative frequency (113.7±17.8 hits/player) and magnitude [2,657.6±432.0 g (PLA), and 233.9 ± 40.1 krad/s² (PRA)] than any other levels-of-contact, whereas air drills showed the lowest cumulative frequency (7.7±1.9 hits/player) and magnitude [176.9±42.5 g (PLA), PRA 16.7±4.2 krad/s² (PRA)]. There was no significant position group difference in cumulative head impact frequency and magnitude in a season. Although there was no difference in average head impact magnitude across five levels-of-contact and by position group PLA (18.2–23.2g) and PRA (1.6–2.3krad/s²) per impact], high magnitude (60-100g and >100g) head impacts were more frequently observed during live and thud drills. Level-of-contact influences cumulative head impact frequency and magnitude in high-school football, with players incurring frequent, high magnitude head impacts during live, thud, and control. It is important to consider level-of-contact to refine clinical exposure guidelines to minimize head impact burden in high-school football.

Spatial regression analysis of MR diffusion reveals subject-specific white matter changes associated with repetitive head impacts in contact sports

Repetitive head impacts (RHI) are a growing concern due to their possible neurocognitive effects, with research showing a season of RHI produce white matter (WM) changes seen on neuroimaging. We conducted a secondary analysis of diffusion tensor imaging (DTI) data for 28 contact athletes to compare WM changes. We collected pre-season and post-season DTI scans for each subject, approximately 3 months apart. We collected helmet data for the athletes, which we correlated with DTI data. We adapted the SPatial REgression Analysis of DTI (SPREAD) algorithm to conduct subject-specific longitudinal DTI analysis, and developed global inferential tools using functional norms and a novel robust p value combination test. At the individual level, most detected injured regions (93.3%) were associated with decreased FA values. Using meta-analysis techniques to combine injured regions across subjects, we found the combined injured region at the group level occupied the entire WM skeleton, suggesting the WM damage location is subject-specific. Several subject-specific functional summaries of SPREAD-detected WM change, e.g., the [Formula: see text] norm, significantly correlated with helmet impact measures, e.g. cumulative unweighted rotational acceleration (adjusted p = 0.0049), time between hits rotational acceleration (adjusted p value 0.0101), and time until DTI rotational acceleration (adjusted p = 0.0084), suggesting RHIs lead to WM changes.

The Drag Crisis Phenomenon on an Elite Road Cyclist-A Preliminary Numerical Simulations Analysis in the Aero Position at Different Speeds

The drag crisis phenomenon is the drop of drag coefficient (C_d) with increasing Reynolds number (Re) or speed. The aim of this study was to assess the hypothetical drag crisis phenomenon in a sports setting, assessing it in a bicycle–cyclist system. A male elite-level cyclist was recruited for this research and his competition bicycle, helmet, suit, and shoes were used. A three-dimensional (3D) geometry was obtained with a 3D scan with the subject in a static aero position. A domain with 7 m of length, 2.5 m of width and 2.5 m of height was created around the cyclist. The domain was meshed with 42 million elements. Numerical simulations by computer fluid dynamics (CFD) fluent numerical code were conducted at speeds between 1 m/s and 22 m/s, with increments of 1 m/s. The drag coefficient ranged between 0.60 and 0.95 across different speeds and Re. The highest value was observed at 2 m/s (C_d = 0.95) and Re of 3.21 × 10⁵, whereas the lower C_d was noted at 9 m/s (C_d = 0.60) and 9.63 × 10⁵. A drag crisis was noted between 3 m/s and 9 m/s. Pressure C_d ranged from 0.35 to 0.52 and the lowest value was observed at 3 m/s and the highest at 2 m/s. The viscous drag coefficient ranged between 0.15 and 0.43 and presented a trend decreasing from 4 m/s to 22 m/s. Coaches, cyclists, researchers, and support staff must consider that C_d varies with speed and Re, and the bicycle–cyclist dimensions, shape, or form may affect drag and performance estimations. As a conclusion, this preliminary work noted a drag crisis between 3 m/s and 9 m/s in a cyclist in the aero position.

Association of Noninvasive Oxygenation Strategies With All-Cause Mortality in Adults With Acute Hypoxemic Respiratory Failure: A Systematic Review and Meta-analysis

IMPORTANCE

Treatment with noninvasive oxygenation strategies such as noninvasive ventilation and high-flow nasal oxygen may be more effective than standard oxygen therapy alone in patients with acute hypoxemic respiratory failure.

OBJECTIVE

To compare the association of noninvasive oxygenation strategies with mortality and endotracheal intubation in adults with acute hypoxemic respiratory failure.

DATA SOURCES

The following bibliographic databases were searched from inception until April 2020: MEDLINE, Embase, PubMed, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, and LILACS. No limits were applied to language, publication year, sex, or race.

STUDY SELECTION

Randomized clinical trials enrolling adult participants with acute hypoxemic respiratory failure comparing high-flow nasal oxygen, face mask noninvasive ventilation, helmet noninvasive ventilation, or standard oxygen therapy.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted individual study data and evaluated studies for risk of bias using the Cochrane Risk of Bias tool. Network meta-analyses using a bayesian framework to derive risk ratios (RRs) and risk differences along with 95% credible intervals (CrIs) were conducted. GRADE methodology was used to rate the certainty in findings.

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality up to 90 days. A secondary outcome was endotracheal intubation up to 30 days.

RESULTS

Twenty-five randomized clinical trials (3804 participants) were included. Compared with standard oxygen, treatment with helmet noninvasive ventilation (RR, 0.40 [95% CrI, 0.24-0.63]; absolute risk difference, -0.19 [95% CrI, -0.37 to -0.09]; low certainty) and face mask noninvasive ventilation (RR, 0.83 [95% CrI, 0.68-0.99]; absolute risk difference, -0.06 [95% CrI, -0.15 to -0.01]; moderate certainty) were associated with a lower risk of mortality (21 studies [3370 patients]). Helmet noninvasive ventilation (RR, 0.26 [95% CrI, 0.14-0.46]; absolute risk difference, -0.32 [95% CrI, -0.60 to -0.16]; low certainty), face mask noninvasive ventilation (RR, 0.76 [95% CrI, 0.62-0.90]; absolute risk difference, -0.12 [95% CrI, -0.25 to -0.05]; moderate certainty) and high-flow nasal oxygen (RR, 0.76 [95% CrI, 0.55-0.99]; absolute risk difference, -0.11 [95% CrI, -0.27 to -0.01]; moderate certainty) were associated with lower risk of endotracheal intubation (25 studies [3804 patients]). The risk of bias due to lack of blinding for intubation was deemed high.

CONCLUSIONS AND RELEVANCE

In this network meta-analysis of trials of adult patients with acute hypoxemic respiratory failure, treatment with noninvasive oxygenation strategies compared with standard oxygen therapy was associated with lower risk of death. Further research is needed to better understand the relative benefits of each strategy.

Helmet Modification to PPE With 3D Printing During the COVID-19 Pandemic at Duke University Medical Center: A Novel Technique

Care for patients during COVID-19 poses challenges that require the protection of staff with recommendations that health care workers wear at minimum, an N95 mask or equivalent while performing an aerosol-generating procedure with a face shield. The United States faces shortages of personal protective equipment (PPE), and surgeons who use loupes and headlights have difficulty using these in conjunction with face shields. Most arthroplasty surgeons use surgical helmet systems, but in the current pandemic, many hospitals have delayed elective arthroplasty surgeries and the helmet systems are going unused. As a result, the authors have begun retrofitting these arthroplasty helmets to serve as PPE. The purpose of this article is to outline the conception, design, donning technique, and safety testing of these arthroplasty helmets being repurposed as PPE.

Childhood cycling fatalities in South Australia before and after the introduction of helmet legislation

In the years following the introduction of legislation in Australian states mandating the wearing of helmets, there was a decline in the number of deaths. Debate has occurred, however, as to why this occurred. The Traffic Accident Reporting System database, which records data for all police-reported crashes in South Australia, was searched for all cases of deaths occurring in the state in bicycle riders aged ≤14 years from January 1982 to December 2001. The numbers of deaths were then compared over the 10-year periods before (1982-1991) and after (1992-2001) the introduction of helmet legislation, and also on a yearly basis from 1982 to 2001. Comparing the numbers of deaths in the two periods before and after helmet legislation in 1991 showed a marked decrease in cases from 36 to 12. However, in examining the numbers of deaths per year in greater detail, it appears that these were already steadily reducing from nine cases per year in 1982 (2.9/100,000) to two cases in 1991 (0.67/100,000) to a virtual plateau after 1991 (ranging from 0 to 2 cases annually). It seems that the introduction of compulsory bicycle helmet wearing in South Australia came at a time when the numbers of child cyclist deaths had been steadily declining over the preceding decade. While helmet wearing clearly protects children who are still riding bicycles, the reasons for the reduction in numbers of deaths appears more complex than legislative change and likely involves a subtle interaction with other behavioural and societal factors and preferences.

Multi-channel whole-head OPM-MEG: Helmet design and a comparison with a conventional system

Magnetoencephalography (MEG) is a powerful technique for functional neuroimaging, offering a non-invasive window on brain electrophysiology. MEG systems have traditionally been based on cryogenic sensors which detect the small extracranial magnetic fields generated by synchronised current in neuronal assemblies, however, such systems have fundamental limitations. In recent years, non-cryogenic quantum-enabled sensors, called optically-pumped magnetometers (OPMs), in combination with novel techniques for accurate background magnetic field control, have promised to lift those restrictions offering an adaptable, motion-robust MEG system, with improved data quality, at reduced cost. However, OPM-MEG remains a nascent technology, and whilst viable systems exist, most employ small numbers of sensors sited above targeted brain regions. Here, building on previous work, we construct a wearable OPM-MEG system with ‘whole-head’ coverage based upon commercially available OPMs, and test its capabilities to measure alpha, beta and gamma oscillations. We design two methods for OPM mounting; a flexible (EEG-like) cap and rigid (additively-manufactured) helmet. Whilst both designs allow for high quality data to be collected, we argue that the rigid helmet offers a more robust option with significant advantages for reconstruction of field data into 3D images of changes in neuronal current. Using repeat measurements in two participants, we show signal detection for our device to be highly robust. Moreover, via application of source-space modelling, we show that, despite having 5 times fewer sensors, our system exhibits comparable performance to an established cryogenic MEG device. While significant challenges still remain, these developments provide further evidence that OPM-MEG is likely to facilitate a step change for functional neuroimaging.

Examining ski area padding for head and neck injury mitigation

OBJECTIVES

The injury mitigation capabilities of foam, ski-area padding was examined for headfirst impacts.

DESIGN AND METHODS

A custom-made pendulum impactor system was constructed using an instrumented, partial 50th-percentile-male Hybrid-III anthropomorphic testing device (ATD). For each test, the ATD was raised 1.0m, released, and swung into a 20-cm diameter wooden pole. Test trials were conducted with the wooden pole covered by ski area padding (five conditions of various foam types and thicknesses) or unpadded. Linear (linear acceleration and HIC₁₅) and angular (angular velocity, angular acceleration, and BrIC) kinematics were examined and used to estimate the likelihood of severe brain injury. Cervical spine loads were compared to the injury assessment reference values for serious injury. Further tests were conducted to examine the changes produced by the addition of a snowsport helmet.

RESULTS

38 test trials were recorded with a mean (±sd) impact speed of 4.2 (±0.03) m/s. Head, resultant linear acceleration, HIC₁₅, and associated injury likelihoods were tempered by ski area padding at the impact speed tested. Ski area padding did not reduce brain injury likelihood from rotational kinematics (p>0.05 for all comparisons) or reduce the cervical spine compression below injury assessment reference values. The addition of a helmet did not reduce significantly the likelihoods of brain or cervical spine injury.

CONCLUSIONS

At the impact speed tested, ski area padding provided limited impact protection for the head (for linear kinematics) but did not protect against severe brain injuries due to rotational kinematics or serious cervical spine injuries.

Analysis of Cyclist's Drag on the Aero Position Using Numerical Simulations and Analytical Procedures: A Case Study

Background: Resistance acting on a cyclist is a major concern among the cycling fraternity. Most of the testing methods require previous training or expensive equipment and time-consuming set-ups. By contrast, analytical procedures are more affordable and numerical simulations are perfect for manipulating and controlling inputs. The aim of this case study was to compare the drag of a cyclist in the aero position as measured using numerical simulation and analytical procedures. Methods: An elite male cyclist (65 kg in mass and 1.72 m in height) volunteered to take part in this research. The cyclist was wearing his competition gear, helmet and bicycle. A three-dimensional model of the bicycle and cyclist in the aero position was obtained to run the numerical simulations. Computational fluid dynamics (CFD) and a set of analytical procedures were carried out to assess drag, frontal area and drag coefficient, between 1 m/s and 22 m/s, with increments of 1 m/s. The t-test paired samples and linear regression were selected to compare, correlate and assess the methods agreement. Results: No significant differences (t = 2.826; p = 0.275) between CFD and analytical procedures were found. The linear regression showed a very high adjustment for drag (R² = 0.995; p < 0.001). However, the drag values obtained by the analytical procedures seemed to be overestimated, even though without effect (d = 0.11). Conclusions: These findings suggest that drag might be assessed using both a set of analytical procedures and CFD.

Laboratory and On-field Data Collected by a Head Impact Monitoring Mouthguard

Although concussion continues to be a major source of acute and chronic injury in automotive, athletic and military arenas, concussion injury mechanisms and risk functions are ill-defined. This lack of definition has hindered efforts to develop standardized concussion monitoring, safety testing and protective countermeasures. Recent research has provided evidence of the role of repetitive head impact exposure as a predisposing factor for the onset of concussion using developed instrumented helmets and mouthguards.To overcome this knowledge gap, we have developed, tested and deployed a head impact monitoring mouthguard (IMM) system. In this study, we deployed the IMM system to gather high quality estimates of athlete head impacts in situ. And with enough longer-term data collection, potential concussive events or mild traumatic brain injuries (mTBIs) will be gathered and ideally will provide actionable risk-based threshold.

Bicycle-related injuries in the emergency department: a comparison between E-bikes and conventional bicycles: a prospective observational study

PURPOSE

To investigate the mechanisms and severity of injuries of e-bikers compared with conventional bicycle (CB) users at the emergency department (ED) of a level 2 trauma center in the Netherlands.

METHODS

We performed a prospective observational study. All patients ≥ 16 years who presented at the ED with an e-bike or conventional bicycle accident were eligible for inclusion. Primary outcomes were mechanisms and severity of injury. Injury severity was defined by the abbreviated injury score and the injury severity score (ISS). Data were analyzed using SPSS (IBM version 24).

RESULTS

A total of 78 e-bikers and 91 CB, were included. The mean age of the e-bikers was 66.9 ± 13.6 years (CB 45.2 ± 20.5 years, P < 0.001). The Charlson comorbidity index was higher in e-bikers (3.1 vs. 1.2, P < 0.001). Mechanism of injury and ISS did not differ between the groups (median ISS 4.0), even though two e-bikers were severely injured (ISS ≥ 16). Alcohol was consumed twice as frequently in CB-related injuries (40% vs. 19.2%, P < 0.01).

CONCLUSION

In this cohort of bicycle injuries in the ED of a level 2 trauma center, e-bikers were older and had more comorbidities than CB users. Except for a higher rate of thoracic and soft-tissue trauma in e-bikers, no differences were found in the mechanism and severity of injury. While it is important to note that helmet use and alcohol avoidance have demonstrable health benefits for bicyclists, further studies to quantify these benefits are recommended.

Infant Cranial Deformity: Cranial Helmet Therapy or Physiotherapy?

Objective: To compare cranial helmet therapy (CHT) and physiotherapy (PT) for the effective treatment of positional plagiocephaly in infants in terms of improving functional recovery. Methods: This was a prospective cohort study involving 48 infants between 5–10 months of age with cranial deformities. The Cranial Vault Asymmetry Index (CVAI) and the Brunet–Lezine scale were calculated at the initiation of the study and after 40 treatment sessions. Results: The infants’ first assessment showed a delay in overall development areas with a global developmental quotient (DQ) (posture, coordination, sociability, and language) of 80.15. Although developmental improvements were observed in both groups in the Brunet–Lezine scale after treatment, the MANCOVA test showed no significant differences (F(5) = 0.82, p = 0.506, eta² = 0.09). The CVAI reduced to 4.07% during the final evaluation in the cranial helmet group and 5.85% in the physiotherapy group without any significant differences between the two therapies (p = 0.70). Conclusions: No statistically significant differences were found between CHT and PT. After treatment, improvements from baseline measurements were observed in each of the readings of cranial deformity.

Mild Hypoxia of a Skydiver Making Repeated, Medium-Altitude Aircraft Exits

INTRODUCTION: Dramatic increases in parachuting safety over the last three decades have been attributed to advances in technology and training for parachutists. However, very little is known about the physiological condition of skydivers making repeated, medium-altitude aircraft exits without using supplemental oxygen. As in aviation, human error is broadly responsible for the majority of skydiving mishaps, although it is unclear what role, if any, physiological factors contribute to these mishaps. Over the course of 2 d, a healthy, 50-yr-old male skydiver executed four normal exits (two jumps per day) from an aircraft between 13,500 and 14,000 ft (4115 and 4267 m) pressure altitude while wearing a helmet-mounted biomonitoring device (SPYDR, Spotlight Labs). On both days, after the subject's second jump, he reported feeling lightheaded and dizzy, symptoms he experiences approximately once every five jumps, and had previously attributed to the excitement of the jump. Inspection of S_po₂ and pulse data revealed that the subject was mildly hypoxic at jump altitude (S_po₂ < 90%). For all four jumps, S_po₂ did not return to normal levels until under canopy. Previous studies have evaluated the cognitive impairment of general aviation pilots operating unpressurized aircraft above 12,500 ft (3810 m) without supplemental oxygen. Alarmingly, mildly hypoxic pilots exhibited twice the rate of procedural errors as compared to normally oxygenated subjects. This study found that the skydiver exited the aircraft with mild hypoxia, which has been associated with cognitive impairment in pilots and could possibly be linked to injuries and/or fatalities.Bradke BS, Everman BR. Mild hypoxia of a skydiver making repeated, medium-altitude aircraft exits. Aerosp Med Hum Perform. 2020; 91(2):110-115.

High-speed helmeted head impacts in motorcycling: A computational study

The motorcyclist is exposed to the risk of falling and impacting ground head-first at a wide range of travelling speeds - from a speed limit of less than 50 km/h on the urban road to the race circuit where speed can reach well above 200 km/h. However, motorcycle helmets today are tested at a single and much lower impact speed, i.e. 30 km/h. There is a knowledge gap in understanding the dynamics and head impact responses at high travelling speeds due to the limitation of existing laboratory rigs. This study used a finite element head model coupled with a motorcycle helmet model to simulate head-first falls at travelling speed (or tangential velocity at impact) from 0 to 216 km/h. The effect of different falling heights (1.6 m and 0.25 m) and coefficient of frictions (0.20 and 0.45) between the helmet outer shell and ground were also examined. The simulation results were analysed together with the analytical model to better comprehend rolling and/or sliding phenomena that are often observed in helmet oblique impacts. Three types of helmet-to-ground interactions are found when the helmet impacts ground from low to high tangential velocities: (1) helmet rolling without slipping; (2) a combination of sliding and rolling; and (3) continuous sliding. The tangential impulse transmitted to the head-helmet system, peak angular head kinematics and brain strain increase almost linearly with the tangential velocity when the helmet rolls but plateaus when the helmet slides. The critical tangential velocity at which the motion transit from the rolling regime to the sliding regime depends on both the falling height and friction coefficient. Typically, for a fall height of 1.63 m and a friction coefficient of 0.45, the rolling/sliding transition occurs at a tangential velocity of 10.8 m/s (38.9 km/h). Low sliding resistance in helmet design, i.e. by the means of a lower friction coefficient between the helmet outer shell and ground, has shown a higher reduction of brain tissue strain in the sliding regime than in the rolling regime. This study uncovers the underlying dynamics of rolling and sliding phenomena in high-speed oblique impacts, which largely affect head impact biomechanics. Besides, the study highlights the importance of testing helmets at speeds covering both the rolling and sliding regime since potential designs for improved head protection at high-speed impacts can be more distinguishable in the sliding regime than in the rolling regime.

Head Movements and Neck Muscle Activity During Air Combat Maneuvering

BACKGROUND: The aim of the study was to determine the characteristics of cervical muscle activity in different head movements when using helmet mounted display in air combat maneuvering.METHODS: Cervical EMG was measured with eight F/A-18 pilots using the Joint Helmet Mounted Cueing System (JHMCS) during air combat maneuvering. In-flight G_z acceleration and continuous head position were recorded. Muscular activity was compared between head movements in isolation and combined with torso movement. In addition, the effect of the direction of head movements and the use of head support of the ejection seat on muscle activity was determined.RESULTS: Muscular loading increased in the cervical flexors and extensors when using the torso during targeting beyond the field of vision in the neutral sitting posture; the difference was significant in the flexors, but activity levels were higher in the extensors. Cervical muscles are loaded to a lesser extent if the head is kept in a stable position during G_z loading. Muscular activity in the neck muscles was higher when the pilot was moving the head out of neutral posture rather than toward neutral posture. The use of the headrest as a support decreased muscle activity in the extensors, but resulted in higher activity in the flexor muscles.DISCUSSION: All analyzed conditions were significantly affected by an increase in G_z. An increase of muscle activity with torso movements is considered as a positive factor as it reflects maintained muscular support for the cervical spine. Presented results may be helpful when specific conditioning programs and cockpit ergonomics are developed for fighter pilots.Sovelius R, Mäntylä M, Huhtala H, Oksa J, Valtonen R, Tiitola L, Leino T. Head movements and neck muscle activity during air combat maneuvering. Aerosp Med Hum Perform. 2020; 91(1):26-31.

Do Type of Helmet and Alcohol Use Increase Facial Trauma Severity?

PURPOSE

Facial trauma caused by motorcycle accidents has become a major issue because of its high prevalence and morbidity, causing death and esthetic and functional sequelae in many individuals. This work evaluated helmet and alcohol use and severity of facial fractures in motorcyclists treated at public hospitals in Pernambuco, Brazil.

PATIENTS AND METHODS

This prospective study was conducted from December 2016 to December 2018 and submitted to statistical and descriptive analysis. Variables such as gender, age, helmet use and type, previous accidents, and duration of hospitalization were collected. The Facial Injury Severity Scale was used to classify the facial fractures. The Alcohol Use Disorders Identification Test was used to verify alcohol dependence.

RESULTS

The sample was composed of 455 patients. Most were male patients (90.8%) and were aged 18 to 29 years (54.5%). Of the patients, 36.5% reported no helmet use and 31.6% reported wearing an open helmet. Alcohol use was reported in 38.7% of the group. In 79.8% of the sample, alcohol use was classified as low risk. There was a greater likelihood of having severe facial trauma if patients were aged between 30 and 39 years and had harmful or at-risk alcohol use. These patients also tended to remain hospitalized for more than 10 days. No statistically significant relationship was found with the type of helmet.

CONCLUSIONS

The individuals most affected by facial trauma were young male patients (aged 18 to 29 years). Patients aged 30 to 39 years with high-risk use and dependence on alcohol were more likely to have more complex facial trauma. The type of helmet used was not effective in reducing the severity of facial fractures.

A network-based response feature matrix as a brain injury metric

Conventional brain injury metrics are scalars that treat the whole head/brain as a single unit but do not characterize the distribution of brain responses. Here, we establish a network-based "response feature matrix" to characterize the magnitude and distribution of impact-induced brain strains. The network nodes and edges encode injury risks to the gray matter regions and their white matter interconnections, respectively. The utility of the metric is illustrated in injury prediction using three independent, real-world datasets: two reconstructed impact datasets from the National Football League (NFL) and Virginia Tech, respectively, and measured concussive and non-injury impacts from Stanford University. Injury predictions with leave-one-out cross-validation are conducted using the two reconstructed datasets separately, and then by combining all datasets into one. Using support vector machine, the network-based injury predictor consistently outperforms four baseline scalar metrics including peak maximum principal strain of the whole brain (MPS), peak linear/rotational acceleration, and peak rotational velocity across all five selected performance measures (e.g., maximized accuracy of 0.887 vs. 0.774 and 0.849 for MPS and rotational acceleration with corresponding positive predictive values of 0.938, 0.772, and 0.800, respectively, using the reconstructed NFL dataset). With sufficient training data, real-world injury prediction is similar to leave-one-out in-sample evaluation, suggesting the potential advantage of the network-based injury metric over conventional scalar metrics. The network-based response feature matrix significantly extends scalar metrics by sampling the brain strains more completely, which may serve as a useful framework potentially allowing for other applications such as characterizing injury patterns or facilitating targeted multi-scale modeling in the future.

Electric scooter injuries at Auckland City Hospital

AIM

Since the introduction of shared electric scooters to Auckland in October 2018, there have been multiple reports of injuries. We aim to examine the pattern of injuries sustained while riding electric scooters in patients presenting to hospital.

METHODS

We conducted a retrospective analysis of patients who presented to Auckland City Hospital Emergency Department (ED) between 15 October 2018 and 22 February 2019. Patients were firstly identified by ED staff and noted in a logbook, and secondly by searching the Trauma Registry database. Outcomes of interest were injuries, imaging, alcohol and helmet use, length of stay and interventions.

RESULTS

There were 180 patients identified. The median length of stay was 4.0 hours, interquartile range (IQR) 18.4 hours. One-third of patients were admitted or transferred. Common injuries were contusions, abrasions and lacerations (65.6%), fractures (41.7%) and head injuries (17.2%). One in five patients (22.2%) required an operation. Only three patients wore a helmet. Of all patients, 23.3% had consumed alcohol, and of those with head injuries; 41.9% had consumed alcohol.

CONCLUSION

This study highlights the significant number of electric scooter-related injuries, including severe head injuries. While the majority of presentations are categorised as minor trauma, these cases have placed additional demand on health system resources. This mode of transport would benefit from greater regulation, including a zero blood alcohol limit, night-time curfews, reduced speed limits and consideration of mandatory helmet use.