A technique for in situ intracranial strain measurement within a helmeted deformable headform.

Despite the broad use of helmets, incidence of concussion remains high. Current methods for helmet evaluation focus on the measurement of head kinematics as the primary tool for quantifying risk of brain injury. Though the primary cause of mild Traumatic Brain Injury (mTBI) is thought to be intracranial strain, helmet testing methodologies are not able to directly resolve these parameters. Computational injury models and impact severity measures are currently used to approximate intracranial strains from head kinematics and predict injury outcomes. Advancing new methodologies that enable experimental intracranial strain measurements in a physical model would be useful in the evaluation of helmet performance. This study presents a proof-of-concept head surrogate and novel helmet evaluation platform that allows for the measurement of intracranial strain using high-speed X-ray digital image correlation (XDIC). In the present work, the head surrogate was subjected to a series of bare and helmeted impacts using a pneumatically-driven linear impactor. Impacts were captured at 5,000 fps using a high-speed X-ray cineradiography system, and strain fields were computed using digital image correlation. This test platform, once validated, will open the door to using brain tissue-level measurements to evaluate helmet performance, providing a tool that can be translated to represent mTBI injury mechanisms, benefiting the helmet design processes.

Incidence of concussions and helmet use in equestrians.

OBJECTIVES: Equestrians have a high risk of concussions per hospital records. However, most concussions occur in private settings where concussions are not tracked. We determined concussion incidence by self-report, expressed per 1000 h of exposure, and determined helmet usage and concussion knowledge. DESIGN: Descriptive epidemiological study. METHODS: Equestrians were recruited using a snowball method of sampling in which enrolled participants recruited more equestrians. Participants completed a survey of equestrian experience and history of concussion, symptoms and provided estimates of hours spent in various equestrian activities. From these data, incidences of concussions were calculated. In addition, they answered questions regarding helmet usage and willingness to take risks when concussed. RESULTS: 210 participants (203 women) reported 27 ±â€¯14 years of equine experience and 728 concussions, 3.47 ±â€¯5.34 per person (0-55). Incidence while riding was 0.19/1000 h which was greater than the incidence while driving (0.02/1000 h) or handling horses (0.03/1000 h). Riders were helmeted at the time of injury 85% of the time. While concussion knowledge was high, most reported willingness to risk permanent injury by continuing to work with horses while injured. CONCLUSIONS: To our knowledge this is the first study to document incidence of concussions in equestrians: incidence is higher while riding than during football or rugby training. Helmets were far more commonly worn at the time of concussion than reported in hospital data, suggesting that helmets effectively reduce concussions severe enough to warrant urgent medical care.

Advantages and drawbacks of helmet noninvasive support in acute respiratory failure.

INTRODUCTION: Non-invasive ventilation (NIV) represents an effective strategy for managing acute respiratory failure. Facemask NIV is strongly recommended in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with hypercapnia and acute cardiogenic pulmonary edema (ACPE). Its role in managing acute hypoxemic respiratory failure (AHRF) remains a debated issue. NIV and continuous positive airway pressure (CPAP) delivered through the helmet are recently receiving growing interest for AHRF management. AREAS COVERED: In this narrative review, we discuss the clinical applications of helmet support compared to the other available noninvasive strategies in the different phenotypes of acute respiratory failure. EXPERT OPINION: Helmets enable the use of high positive end-expiratory pressure, which may protect from self-inflicted lung injury: in AHRF, the possible superiority of helmet support over other noninvasive strategies in terms of clinical outcome has been hypothesized in a network metanalysis and a randomized trial, but has not been confirmed by other investigations and warrants confirmation. In AECOPD patients, helmet efficacy may be inferior to that of face masks, and its use prompts caution due to the risk of CO2 rebreathing. Helmet support can be safely applied in hypoxemic patients with ACPE, with no advantages over facemasks.

National incidence and trends of bicycle injury.

Bicycle utilization continues to increase annually, and this trend was recently accelerated by the coronavirus disease of 2019 pandemic. There is limited epidemiologic data, however, regarding the prevalence and nature of bicycle-related injuries. Therefore, the purpose of this study is to characterize trends in bicycle-related injuries. The National Electronic Injury Surveillance System was queried for bicycle-related injuries from 2012 to 2021. Patient demographic and injury data were collected and analyzed to describe trends in incidence, patient demographics, and injury patterns associated with an emergency department encounter for a bicycle-related injury. There were an estimated 4,666,491 (95% confidence interval: 4,661,472-4,671,510) bicycle-related injuries from 2012 to 2021. The incidence of these injuries has significantly decreased over time (R = -0.983, R2 = 0.967, p < 0.001). However, the rate of injury in elderly patients increased over time. Injuries occurred most often during summer months (36%) and on weekend days (31.9%). Males and younger patients were more commonly injured. Head injuries were the most commonly affected body part among all age groups. Fractures were the most common injury type overall. Upper extremity injuries were more common than the lower extremity. Despite increased public bicycle utilization, there is a significant downtrend in bicycle-related injuries over the last decade. Injuries among elderly patients are becoming more common, who demonstrate a high rate of fracture and head injury. Fractures and head injuries were the most common injuries among all age groups, highlighting the importance of bicycle safety initiatives and helmet-wearing regardless of age.

Experimental research of energy absorbing structures within helmet samples made with the additive manufacturing method - preliminary study.

PURPOSE: This study aimed to develop an energy-absorbing structure for bicycle helmets to minimize head injuries caused by collisions. The research team explored three geometric structures produced through additive methods and compares their energy absorption properties with a standard bicycle helmet made of Expanded Polystyrene (EPS) foam. METHODS: The study prepared samples of three geometric structures (a ball, a honeycomb and a conical shape) and a fragment of a bicycle helmet made of EPS foam with the same overall dimensions. Laboratory tests were conducted using a pneumatic hammer, piston compressor, anvil, triaxial accelerometer and data processing systems. Three crash tests were performed for each type of structure, and the anvil's maximum acceleration and stopping distance after the crash were analyzed. RESULTS: The study found that the energy absorption properties of the Polylactic Acid (PLA) material printed with the incremental method were comparable or better than those of the EPS material used in helmets. The geometric structure of the energy-absorbing material played a crucial role in its effectiveness. The most promising results were obtained for the ball samples. CONCLUSIONS: The study concluded that further research on energy-absorbing structures made using the Fused Deposition Modeling (FDM) method could be useful in the production of bicycle helmets. The results show that the geometric structure of the energy-absorbing material is a crucial factor in its effectiveness. The findings suggest that the ballshaped structure made with PLA material printed using the incremental method could be a promising design for bicycle helmets to minimize head injuries caused by collisions.

Drill Intensity and Head Impact Exposure in Adolescent Football.

BACKGROUND AND OBJECTIVES: The objective of this study was to examine head-impact exposure by intensity level and position group, and to test the hypothesis that there would be an increase in cumulative head-impact exposure between drill intensities after controlling for duration in each level with air recording the lowest frequency and magnitude and live recording the highest: air < bags < control < thud < live. METHODS: We conducted a prospective, multisite study in 1 season with players from 3 high school football teams (n = 74). Each player wore a sensor-installed mouthguard, which monitored head-impact frequency, peak linear acceleration (PLA), and peak rotational acceleration (PRA). Practice drills and games were categorized by level of contact. RESULTS: A total of 7312 impacts were recorded with a median of 67 (interquartile range:128) impacts per player. After controlling for duration, increases in head-impact outcomes by level of contact were observed (air < bags = control < thud = live). Live drills had higher cumulative head-impact frequency (45.4 ± 53.0 hits) and magnitude (PLA: 766.3 ± 932.9 g; PRA: 48.9 ± 61.3 kilorad/s2) per player than other levels (P < .0001). In comparison, air drills had the lowest cumulative frequency (4.2 ± 6.9 hits) and magnitude (PLA: 68.0 ± 121.6 g; PRA: 6.4 ± 13.2 kilorad/s2). CONCLUSIONS: These data support the levels-of-contact system as a practical approach to limiting head-impact exposure in tackle football. Our findings are clinically important, because data have begun to suggest the relationship between chronic head-impact exposure and decline in brain health. Since head-impact exposure was influenced by levels of contact, regulation of the duration of certain drill intensities (eg, thud, live) may associate with reduced head-impact exposure in high school football.

Under the Helmet: Perioperative Concussion-Review of Current Literature and Targets for Research.

Patients with recent concussion experience disruption in neurocellular and neurometabolic function that may persist beyond symptom resolution. Patients may require anesthesia to facilitate diagnostic or surgical procedures following concussion; these procedures may or may not be related to the injury that caused the patient to sustain a concussion. As our knowledge about concussion continues to advance, it is imperative that anesthesiologists remain up to date with current principles. This Focused Review will update readers on the latest concussion literature, discuss the potential impact of concussion on perianesthetic care, and identify knowledge gaps in our understanding of concussion.

Role of helmet ventilation during the 2019 coronavirus disease pandemic.

Coronavirus disease 2019 (COVID-19) has been declared a pandemic by the World Health Organization; it has affected millions of people and caused hundreds of thousands of deaths. Patients with COVID-19 pneumonia may develop acute hypoxia respiratory failure and require noninvasive respiratory support or invasive respiratory management. Healthcare workers have a high risk of contracting COVID-19 while fitting respiratory devices. Recently, European experts have suggested that the use of helmet continuous positive airway pressure should be the first choice for acute hypoxia respiratory failure caused by COVID-19 because it reduces the spread of the virus in the ambient air. By contrast, in the United States, helmets were restricted for respiratory care before the COVID-19 pandemic until the Food and Drug Administration provided the 'Umbrella Emergency Use Authorization for Ventilators and Ventilator Accessories'. This narrative review provides an evidence-based overview of the use of helmet ventilation for patients with respiratory failure.

Skateboard head injuries: Are we making progress?

BACKGROUND: Skateboarding is a popular sport and U.S. trauma centers care for a significant number of skateboard-related injuries (SRIs). However, injury prevention strategies are still underdeveloped. This study was designed to compare the epidemiology, type, and location of skateboard injury as well as the use and influence of protective gear over two time periods. METHODS: This is a retrospective National Trauma Data Bank study including all patients with SRIs between 2007and 2016. Study groups were divided into two 5-year periods: 2007-2011 and 2012-2016. The incidence and severity of traumatic brain injury (TBI), as well as the compliance and effectiveness of protective gear and skate parks, was assessed in various age groups in the two study periods using univariable and multivariable analyses. Univariable analysis was used to compare the two study periods, logistic regression analysis was performed to identify independent predictors of head injury and severe TBI. RESULTS: 24,903 patients presented with SRIs: 10,594 from 2007 to 2011 and 14,309 from 2012 to 2016. Helmet use was low in both periods (5.7% and 5.4% respectively). The incidence of severe TBI (head AIS≥3) did not change significantly during the two periods (31.6% vs. 30.8%, p = 0.162). In children with severe TBI, there was no significant difference in helmet use across all ages, (10.4% vs. 11.5%, p = 0.467; 6.4% vs. 6.5%, p = 0.753; 4.2% vs. 3.7%, p = 0.201, respectively) with the lowest usage in the older than 16 years age group. On logistic regression, male gender (OR 1.526, 95% CI 1.372-1.698, p<0.001) was associated with increased odds of severe TBI, while helmet use (OR 0.534, 95% CI 0.455-0.627, p<0.001) and injuries at skate parks (OR 0.584, 95% CI 0.541-0.630, p<0.001), near home (OR 0.465, 95% CI 0.418-0.518, p<0.001), and public buildings (OR 0.386, 95% CI 0.440-0.541, p<0.001) were associated with reduced odds of severe TBI. CONCLUSIONS: Helmet use in patients with SRIs is low in all pediatric age groups. Helmet use and skate parks are protective against severe TBI. Older age children and male gender are at increased risk of severe TBI after skateboard-related injuries, and more targeted preventive education and legislation are needed.

Postoperative Infection Rates After Total Ankle Arthroplasty: A Comparison With and Without the Use of a Surgical Helmet System.

Following total joint arthroplasty, surgical site infections (SSI) and periprosthetic joint infections (PJI) are associated with increased patient morbidity and healthcare utilization. Current positive-pressure surgical sterile helmet system (SHS) were developed as a feasible, useful version of the body exhaust system.The use of SHS has not yet been proven to decrease infection rates in the orthopedic literature. The primary purpose of this study is to compare the infection rates between patients who underwent total ankle arthroplasty (TAA) with a surgical team wearing SHS versus without SHS.A retrospective chart review in patients undergoing primary TAA with the surgeon wearing SHS (Group 1) or standard surgical attire (Group 2) was conducted. The primary outcome was postoperative SSI and PJI. The rate of wound complications, revision rates, and associated procedures were also analyzed. We identified 109 patients in Group 1 and 151 patients in Group 2. The rate of SSI was 12.8% in Group 1 and 14.6% in Group 2 (p = .411). The rate of PJI was 0.92% in Group 1 and 2.6% in Group 2 (p = .411). There was no difference in revision rates between the two groups. This study suggests that SHS does not appear to protect against postoperative SSI or PJI after TAA. Conversely, we did not find a higher infection rate compared to standard surgical attire despite recent in-vitro studies suggesting SHS as a source of wound contamination. The utility of SHS does not appear to influence the prevalence of postoperative SSI or PJI.

Surgical Helmet Systems Are Associated With a Lower Rate of Prosthetic Joint Infection After Total Knee Arthroplasty: Combined Results From the New Zealand Joint Registry and Surgical Site Infection Improvement Programme.

BACKGROUND: This study aimed to identify the risk factors, in particular the use of surgical helmet systems (SHSs), for prosthetic joint infection (PJI) after total knee arthroplasty (TKA). Data recorded by the New Zealand Surgical Site Infection Improvement Programme (SSIIP) and the New Zealand Joint Registry (NZJR) were combined and analyzed. METHODS: Primary TKA procedures performed between July 2013 and June 2018 that were recorded by both the SSIIP and NZJR were analyzed. Two primary outcomes were measured: (1) PJI within 90 days as recorded by the SSIIP and (2) revision TKA for deep infection within 6 months as recorded by the NZJR. Univariate and multivariate analyses were performed to identify risk factors for both outcomes with results considered significant at P < .05. RESULTS: A total of 19,322 primary TKAs were recorded by both databases in which 97 patients had a PJI within 90 days as recorded by the SSIIP (0.50%), and 90 patients had a revision TKA for deep infection within 6 months (0.47%) as recorded by the NZJR. An SHS was associated with a lower rate of PJI (adjusted odds ratio [OR] = 0.50, P = .008) and revision for deep infection (adjusted OR = 0.55, P = .022) than conventional gowning. Male sex (adjusted OR = 2.6, P < .001) and an American Society of Anesthesiologists score >2 were patient risk factors for infection (OR = 2.63, P < .001 for PJI and OR = 1.75, P = .017 for revision for deep infection). CONCLUSION: Using contemporary data from the SSIIP and NZJR, the use of the SHS was associated with a lower rate of PJI after primary TKA than conventional surgical gowning. Male sex and a higher American Society of Anesthesiologists score continue to be risk factors for infection.

Modification of hurling helmets causing penetrating upper limb injury: A case series demonstrating opportunity for improved player safety.

BACKGROUND: The games of hurling and camogie involve fast ball movement and a substantial physical contact with opposing players. The wearing of protective helmets with faceguards became obligatory 10 years ago and resulted in a significant reduction of craniofacial injuries. However since then a trend has emerged of players modifying helmets to improve comfort and vision. As officials are not yet required to perform pre-match checks, many players enter competition with defective protective equipment which poses a risk to both themselves and others. METHODS: We present 4 cases of penetrating upper limb injury in hurlers sustained as a result of helmet faceguards. These injuries were sustained during competitive play and the affected patients presented with portions of the faceguards embedded in their wounds. Each patient required admission to hospital and exploration of their wounds under general anaesthetic. CONCLUSIONS: This case series demonstrates the dangers of modification and damage to protective helmet faceguards used in hurling and camogie. We encourage helmet manufacturers to re-engage with players to ensure that current safety equipment meets the functional demands of the modern player while adhering to approved manufacturing standards. Mandatory helmet checks before competitive games would reduce the likelihood of penetrating upper limb injury to players.

Epidemiology and Injury Pattern of E-Scooter Injuries - Initial Results. / Verletzungen mit E-Scootern ­ erste Ergebnisse zu Epidemiologie und Verletzungsmustern.

AIM: Since the introduction of shared electric scooters in Germany in June 2019, surgeons have been treating injuries caused by these devices. METHODS: In our Institution, we implemented the first registry to examine the pattern of injuries and to gather epidemiological data on persons injured while riding electric scooters. We conducted a prospective analysis of all patients treated in our Emergency Department for an injury sustained while riding an electric scooter between June 2019 and June 2020. All patients were noted in a registry (E-SCORE = E-Scooter Register). The study was approved by the institutional ethics board. Outcomes were first time of use, injuries, imaging, alcohol and helmet use, age, length of hospital stay and surgical therapy. RESULTS: 90 patients were identified. Mean age was 35.6 years (± 15.4); 65.5% were male. We diagnosed 32 fractures and 7 ligament injuries. Injuries to the head were found in 38 patients; 8 had relevant intracerebral or maxillofacial injuries. Alcohol use was noted in 18 (20%) patients, only 2 of whom wore a helmet (2.2%). 29 patients (32.2%) required surgical intervention. CONCLUSION: This study highlights the significant number of head injuries in patients riding electric scooters. Nevertheless, there are also a significant number of injuries to the bones and ligaments, which required surgical treatment. Hardly any of the patients was wearing a helmet and alcohol use was not unusual. In our opinion, scooter related injuries are leading to an growing number of vehicle related injuries and could probably benefit from some legal regulations, such as a blood alcohol limit and recommendation for helmet use. Implementation of a nationwide registry might be useful in evaluating injuries related to electric scooters.

Comparison of head impact frequency and magnitude in youth tackle football and ice hockey.

Repetitive head impacts are a growing concern for youth and adolescent contact sport athletes as they have been linked to long term negative brain health outcomes. Of all contact sports, tackle football and ice hockey have been reported to have the highest incidence of head or brain injury however, each sporting environment is unique with distinct rules and regulations regarding contact and collisions. The purpose of this research was to measure and compare the head impact frequency and estimated magnitude of brain tissue strain, amongst youth tackle football and ice hockey players during game play. Head impact frequency was documented by video analysis of youth tackle football and ice hockey game play. Impact magnitude was determined through physical laboratory reconstructions and finite element modelling to estimate brain tissue strains. Tackle football demonstrated significantly higher impact frequency (P < 0.01) and magnitude of estimated brain tissue strains (P < 0.01) compared to ice hockey. A significantly higher number of higher strain head impacts were documented in tackle football when compared to ice hockey (P < 0.01). These differences suggest that youth football players may experience increased frequency and magnitude of estimated brain tissue strains in comparison to youth hockey.

A Systematic Review of Head, Neck and-Facial Injuries in Cricket.

This systematic review was conducted to identify the incidence, nature and mechanisms of head, neck and facial (HNF) injuries in cricket and the reported use of helmets. Five databases were searched up to 30th November 2020. From peer-reviewed cricket injury studies published in English, studies reporting on HNF cricket injuries as per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were selected. Twenty-nine studies were included. HNF injuries had a cumulative total of 794/5,886 injuries equating to 13% of all injuries. Non- specified HNF injuries (n=210, 26%) were the most prevalent type of injury followed by non-specified head injuries (n=130, 16%), other non-specified fractures (n=119, 15%) and concussions (n=60, 8%).The impact of the ball was reported as the most common mechanism for sustaining HNF injuries in cricket. The use of helmet was reported in only three studies (10%). From studies reporting on HNF cricket injuries, facial fractures, and concussions were the most common specified-types of injury. There is little evidence on reporting of HNF cricket injuries as per the international cricket consensus injury definitions, as well as the use of helmets at the time of injury.

The association of padded headgear with concussion and injury risk in junior Australian football: A prospective cohort study.

OBJECTIVES: To assess whether padded headgear was associated with incidence of suspected sports-related concussion, non-sports-related concussion head injury, and injuries to other body regions in junior Australian football. DESIGN: Prospective cohort injury surveillance. METHODS: There were 400 junior players (42.5% female) enrolled across two seasons. Suspected sports-related concussion was defined by detection of observable signs on the field and medical assessment or missed match(es) due to suspected sports-related concussion. Non-sports-related concussion head injury and injuries to other body regions were defined as those that received medical assessment or resulted in a missed match. RESULTS: There were 20 teams monitored over 258 matches. 204 players (2484 player hours) wore mandated headgear throughout the season and 196 (2246 player hours) did not. The incidence rate of suspected sports-related concussion was 3.17 (95% confidence interval: 3.04-3.30) per 1000 player-hours and no differences were observed between males and females (risk ratio 1.11; 95% confidence interval: 0.40-3.06). Headgear use was not associated with suspected sports-related concussion (risk ratio 1.09; 95% confidence interval: 0.41-2.97), non-sports-related concussion head injury (risk ratio 0.27; 95% confidence interval: 0.06-1.31), or injuries to other body regions (risk ratio 1.41; 95% confidence interval: 0.79-2.53). CONCLUSIONS: Headgear use was not associated with reduced risk of suspected sports-related concussion, non-sports-related concussion head injury or injuries to other body regions. There was no difference in the rate of suspected sports-related concussion in female compared to male players, however, rates of non-sports-related concussion head injury and injuries to other body regions were higher in male players.

The roles of noninvasive mechanical ventilation with helmet in patients with acute respiratory failure: A systematic review and meta-analysis.

OBJECTIVE: To compare the safety and effectiveness between helmet and face mask noninvasive mechanical ventilation (NIMV) in patients with acute respiratory failure (ARF). METHODS: English databases included PubMed, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science. Chinese databases involved Wanfang Data, China Knowledge Resource Integrated Database and Chinese Biological Medicine Database. Randomized controlled trials (RCTs) comparing helmet and face mask NIMV for patients with ARF were searched. Meta-analysis was performed using Review manager 5.1.0. RESULTS: Twelve trials with a total of 569 patients were eligible. Our meta-analysis showed that, comparing with face mask, helmet could significantly decrease the incidences of intolerance [risk ratio (RR) 0.19; 95% confidence interval (CI) 0.09-0.39], facial skin ulcer (RR 0.19; 95% CI 0.08-0.43) and aerophagia (RR 0.15; 95% CI 0.06-0.37), reduce respiratory rate [mean difference (MD) -3.10; 95% CI -4.85 to -1.34], intubation rate (RR 0.39; 95% CI 0.26-0.59) and hospital mortality (RR 0.62; 95% CI 0.39-0.99) in patients with ARF, and improve oxygenation index in patients with hypoxemic ARF (MD 55.23; 95% CI 31.37-79.09). However, subgroupanalysis for hypercapnic ARF revealed that PaCO2 was significantly reduced in face mask group compared with helmet group (MD 5.34; 95% CI 3.41-7.27). CONCLUSION: NIMV with helmet can improve the patient's tolerance, reduce adverse events, increase oxygenation effect, and decrease intubation rate and hospital mortality comparing to face mask. However, the low number of patients from included studies may preclude strong conclusions. Large RCTs are still needed to provide more robust evidence.

[Incidence of musculoskeletal disorders in police officers riding motorcycles while on duty]. / Wystepowanie dolegliwosci ze strony narzadu ruchu u policjantów pelniacych sluzbe na motocyklach.

BACKGROUND: Riding a motorcycle involves a risk of suffering from ailments of the musculoskeletal system. These can be caused, i.a., by long-term persistence of a unfavorable body position, vibrations or the necessity of wearing a protective helmet. One of the occupational groups that use motorcycles are road traffic police officers. There are few literature reports of ailments related to riding a motorcycle, especially as regards police officers using these vehicles while on duty. The key objective of this research was to investigate the occurrence of locomotor system disorders during a motorcycle ride or after it, among Polish police officers who actively ride motorcycles. Factors which can affect the occurrence and characteristics of those disorders were also verified. MATERIAL AND METHODS: A survey including 42 questions was used in the research. After obtaining the consent from the Police Commander-in-Chief, 485 questionnaires were distributed to selected Provincial Police Headquarters, 377 of which were eventually approved for statistical analysis. RESULTS: In 57.37% of the investigated police officers who regularly rode motorcycles while on duty, ailments of the locomotor system were reported, which most often appeared after a long ride (53.46%), and usually disappeared within a few hours after its end (60.65%). The ailments were found to mostly occur in the lumbosacral (76.17%) and cervical spine (50.93%); however, the highest intensity was observed in the lumbosacral spine (5.86%) and knee joints (5.11%). Also, there was a direct connection between pain and years of service on a motorcycle (p = 0.014), the average monthly distance (p = 0.036), and past motorcycle accidents (p = 0.001), or other accidents (p = 0.002). CONCLUSIONS: The Polish police officers experience locomotor system disorders related to riding a motorcycle while on duty. The factors affecting their occurrence include experience in riding a motorcycle, the monthly distance covered, and accidents. Med Pr. 2020;71(2):177-86.

Traumatic medial clavicle fracture induced by chin bar of a full-face helmet following a downhill mountainbike accident.

Downhill mountain biking is a rapidly growing sport. In our case we want to present an isolated medial clavicular fracture following a mountain bike accident with a critical review on the used protection device. A 35 year old healthy patient presented to our hospital after bike accident during downhill mountain biking in Austria with pain over his right medial clavicle. The imaging showed a multifragmentary medial clavicle fracture with an intact SC-joint. Surgical intervention was recommended. Postoperative x-rays showed an anatomic reposition and correct plate positioning. The implant was removed after 18 months without any complications. A full-face helmet with a chin bar is used to achieve better protection of the maxilla, mandible and the teeth. In a hyperflexion situation of the cervical spine, a direct contact of the chin bar with the sternum, sc-joint and the medial clavicle can occur. This impact sets the mentioned structures on a high risk of dislocation and fracture as seen in our case. This risk can be significantly reduced by the combined use of a full face helmet and a neck brace. If the injury is properly identified, positive results can be achieved by surgery.

UK military helmet design and test methods.

The aim of this paper was to provide the military medical community with an expert summary of military helmets used by HM Armed Forces. The design of military helmets and test methods used to determine the fragmentation and non-ballistic impact protection are discussed. The helmets considered are Parachutist, Combat Vehicle Crewman, Mk6, Mk6A, Mk7 and VIRTUS. The helmets considered provide different levels of fragmentation and non-ballistic impact protection dictated by the materials available at the time of the helmet design and the end-user requirement. The UK Ministry of Defence defines the area of coverage of military helmets by considering external anatomical features to provide protection to the brain and the majority of the brainstem. Established test methods exist to assess the performance of the helmet with respect to the threats; however, these test methods do not typically consider anatomical vulnerability.