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Sports-related mild traumatic brain injury (mTBI) is a growing public health concern, affecting millions in the U.S., annually. Current helmets are primarily designed to mitigate head kinematics, despite the importance of the brain substructures mechanics in mTBI mechanism. Therefore, it is crucial to consider the dynamical behavior of brain substructures, which has been shown in prior studies to be associated with strain concentration. Here, we studied the modal behavior and strain patterns of the substructures of the brain finite element (FE) model through Dynamic Mode Decomposition. We conducted side and front impact pendulum tests on a dummy headform equipped with hockey, football, ski, and bicycle helmets. After simulating the impact tests using a brain FE model, we calculated the dynamic modes of this computational model for the whole brain, corpus callosum, brainstem, and cerebellum. The main mode of oscillation in all regions for all helmet types occurred around the frequency regime of 7–15 Hz. Also, in cerebellum, a second harmonic was observed at 40–50 Hz in front impact, and 38 and 62 Hz in side impact in bicycle and ski helmets, respectively. Furthermore, we analyzed the correlation between the modal response and peak maximum principal strain (MPS). These analyses mostly showed a direct association between the computational modal behavior and MPS, where helmet tests with closely spaced modes and high-frequency modal amplitudes led to higher MPS values. This association between the computational modal behavior and strain patterns demonstrated a potential for improving helmet designs through a novel design objective.Statement of significance: Sport-related mild traumatic brain injury (mTBI), which is one of the leading cause of death, can be reduced in severity by using headgears including helmets. Despite the recent innovations and technologies in helmet design, there are important factors that still have been missed. While it’s been shown that the brain substructures mechanics play an important role in mTBI mechanism, current helmets are designed to only mitigate the head kinematics. Moreover, dynamical behavior of these substructures, and existence of multimodal behavior in the brain are factors that have not been addressed in designing helmets. This paper shows the effect of different helmet types on modal behavior of the brain substructures and how the dynamical modes of these regions can be affected by using various helmet types.

Participants in American football experience repetitive head impacts that induce negative changes in neurocognitive function over the course of a single season. This study aimed to quantify the transfer function connecting the force input to the measured output acceleration of the helmet system to provide a comparison of the impact attenuation of various modern American football helmets. Impact mitigation varied considerably between helmet models and with location for each helmet model. The current data indicate that helmet mass is a key variable driving force attenuation, however flexible helmet shells, helmet shell cutouts, and more compliant padding can improve energy absorption. [ABSTRACT FROM AUTHOR]

Traditionally, the product design has been based on physical experiments using different prototypes. Nowadays, the evolution of the computers has an important effect on the product design, it is based on the computer software from the conception phase. This paper presents an aerodynamic evaluation of a motorcycle helmet model using CFD simulation methods. The beginning of the evaluation includes the current state of the art regarding the computational methods for evaluate the aerodynamic performance of the motorcycle helmet, followed by the mathematical approach applied in this paper establishment of the airflow regime. Another part of the paper presents the CAD design of the motorcycle helmet modelled in five variants and performing the CFD simulation at 33.34 m/s airflow velocity for each helmet variant. The resulted aerodynamic force and the aerodynamic coefficient for each simulation model are discussed in the third part of the paper. The end of the paper presents the conclusions of this aerodynamic study, highlighting the advantages and disadvantages of using the CFD simulation to establish the helmet aerodynamics. [ABSTRACT FROM AUTHOR]

Sports-related traumatic brain injuries (TBIs) are among the leading causes of head injuries in the world. Use of helmets is the main protective measure against this epidemic. The design criteria for the majority of the helmets often only consider the kinematics of the head. This approach neglects the importance of regional deformations of the brain especially near the deep white matter structures such as the corpus callosum (CC) which have been implicated in mTBI studies. In this work, we develop a dynamical reduced-order model of the skull-brain-helmet system to analyze the effect of various helmet parameters on the dynamics of the head and CC. Here, we show that the optimal head–helmet coupling values that minimize the CC dynamics are different from the ones that minimize the skull and brain dynamics (at some kinematics, up to two times stiffer for the head motion mitigation). By comparing our results with experimental impact tests performed on seven different helmets for five different sports, we found that the football helmets with an absorption of about 65–75% of the impact energy had the best performance in mitigating the head motion. Here, we found that none of the helmets are effective in protecting the CC from harmful impact energies. Our computational results reveal that the origin of the difference between the properties of a helmet mitigating the CC motion vs. the head motion is nonlinear vs. linear dynamics. Unlike the globally linear behavior of the head dynamics, we demonstrate that the CC exhibits nonlinear mechanical response similar to an energy sink. This means that there are scenarios where, at the instant of impact, the CC does not undergo extreme motions, but these may occur with a time delay as it absorbs shock energy from other parts of the brain. These findings hint at the importance of considering tissue level dynamics in designing new helmets. [ABSTRACT FROM AUTHOR]

Traditionally, the product design has been based on physical experiments using different prototypes. Nowadays, the evolution of the computers has an important effect on the product design, it is based on the computer software from the conception phase. This paper presents an aerodynamic evaluation of a motorcycle helmet model using CFD simulation methods. The beginning of the evaluation includes the current state of the art regarding the computational methods for evaluate the aerodynamic performance of the motorcycle helmet, followed by the mathematical approach applied in this paper establishment of the airflow regime. Another part of the paper presents the CAD design of the motorcycle helmet modelled in five variants and performing the CFD simulation at 33.34 m/s airflow velocity for each helmet variant. The resulted aerodynamic force and the aerodynamic coefficient for each simulation model are discussed in the third part of the paper. The end of the paper presents the conclusions of this aerodynamic study, highlighting the advantages and disadvantages of using the CFD simulation to establish the helmet aerodynamics.

Based on reverse engineering, product innovation design and 3D-printing technology, a technical route for the rapid design and development of helmet products has been constructed, and optimize the product production process, reduce the product development cycle, improve production efficiency, and complete the personalized design of helmets to improve the comfort of personnel wearing. The point cloud data of the physical model were collected by the 3D scanner, and imported to the reverse processing software (Geomagic Studio) for data processing, surface reconstruction and surface fitting. In this way, the section curve of the repaired head surface was extracted. Then, the extracted information was sent to the forward design software (SolidWorks) through the parameter exchange command for the forward design of the helmet, and the 3D model was subsequently printed. Effectively solve the traditional design method for complex surface modelling design and manufacturing, forward software measurement deviation, modelling design process is complex and tedious, time-consuming and labor-intensive, cannot well meet the product design, processing and manufacturing process is relatively cumbersome, long production cycle and other design defects, speed up enterprise product development, shorten the cycle and reduce costs. Furthermore, the adoption of 3D printing technology to output the designed 3D digital model effectively shortens the product development cycle.

Many animals have protective anatomical structures that allow for growth and flexibility; these structures contain thin seams called sutures that help the structure to absorb impacts. In this study, we parameterized the stiffness and toughness of a curved archway structure based on three geometric properties of a suture through finite element, quasi-static, three-point bending simulations. Each archway consisted of two symmetric pieces linked by a dovetail suture tab design. The three parameters included suture tab radii (1-5 mm), tangent lengths (0-20 mm), and contact angles (0-40°). In the simulations, a steel indenter was displaced 6.5 mm to induce progressive tab disengagement. Sutures with large contact angles and large tangent lengths generally led to stiffer and tougher structures. Sutures with a small tab radius exhibited the most sensitivity to the input parameters, and the smallest tab radius led to the stiffest and toughest archways. Results suggested that it was a combination of the largest number of tab repeats with the largest possible contact surface area that improved the mechanical response of the archway. The study revealed several suture geometries that hold significant promise, which can aid in the development of hemispherical 3D structures for dynamic impact applications. [ABSTRACT FROM AUTHOR]

In this study, a novel expandable bicycle helmet, which integrates an airbag system into the conventional helmet design, was proposed to explore the potential synergetic effect of an expandable airbag and a standard commuter-type EPS helmet. The traumatic brain injury mitigation performance of the proposed expandable helmet was evaluated against that of a typical traditional bicycle helmet. A series of dynamic impact simulations on both a helmeted headform and a representative human head with different configurations were carried out in accordance with the widely recognised international bicycle helmet test standards. The impact simulations were initially performed on a ballast headform for validation and benchmarking purposes, while the subsequent ones on a biofidelic human head model were used for assessing any potential intracranial injury. It was found that the proposed expandable helmet performed admirably better when compared to a conventional helmet design--showing improvements in impact energy attenuation, as well as kinematic and biometric injury risk reduction. More importantly, this expandable helmet concept, integrating the airbag system in the conventional design, offers adequate protection to the cyclist in the unlikely case of airbag deployment failure. [ABSTRACT FROM AUTHOR]

Based on reverse engineering, product innovation design and 3D-printing technology, a technical route for the rapid design and development of helmet products has been constructed, and optimize the product production process, reduce the product development cycle, improve production efficiency, and complete the personalized design of helmets to improve the comfort of personnel wearing. The point cloud data of the physical model were collected by the 3D scanner, and imported to the reverse processing software (Geomagic Studio) for data processing, surface reconstruction and surface fitting. In this way, the section curve of the repaired head surface was extracted. Then, the extracted information was sent to the forward design software (SolidWorks) through the parameter exchange command for the forward design of the helmet, and the 3D model was subsequently printed. Effectively solve the traditional design method for complex surface modelling design and manufacturing, forward software measurement deviation, modelling design process is complex and tedious, time-consuming and labor-intensive, cannot well meet the product design, processing and manufacturing process is relatively cumbersome, long production cycle and other design defects, speed up enterprise product development, shorten the cycle and reduce costs. Furthermore, the adoption of 3D printing technology to output the designed 3D digital model effectively shortens the product development cycle. [ABSTRACT FROM AUTHOR]

Background:  Kendo, a martial art developed by the samurai, is rooted deep in Japanese culture with traditional armor that has seen little change over the past centuries. Despite its century-old design, kendo helmets are manufactured without third-party testing to verify their quality and effectiveness against head trauma., Objective: To evaluate the effectiveness of different helmet stitching patterns and padding materials in mitigating impact forces that could lead to sports-related concussions (SRC) in kendo, and to assess variations in safety performance across different genders and kendo ranks (Dan and Kyu)., Methods: We collected data from 10 kendo practitioners (six males and four females), analyzing over 4,000 strikes using shinai on a sensor-equipped mannequin. Various helmet stitching patterns (ranging from 2 mm to 9 mm) and padding types (polyurethane-based and different thicknesses of cotton-based pads) were tested under controlled conditions simulating realistic impacts encountered in kendo practice., Results: The results indicated that helmets with wider stitching patterns (e.g. 8 mm and 9 mm) generally offered better energy absorption, exhibiting statistically significant lower mean g-forces with a 95% confidence interval compared to tighter patterns (2 mm, 4 mm, 6 mm, and 8 mm x 2 mm) (p < 0.001). Additionally, the polyurethane-based padding outperformed cotton-based padding by a statistically significant reduction of impact force (p < 0.001). Significant differences in striking force were also observed between genders and ranks, with male and higher-rank (Dan) practitioners delivering stronger impacts (both p < 0.001)., Conclusions: This study highlights the critical influence of helmet stitching patterns and padding materials on the protective capabilities against concussions in kendo. Even though helmets with narrower stitching patterns cost more, helmets with wider stitching patterns and polyurethane padding material provide enhanced safety benefits. We do not know how the difference in striking force between genders and ranks affects the outcome of a kendo match., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. California Northstate University Institutional Review Board issued approval 2403-02-150. This project was approved by CNU Institutional Review Board on 5/7/24. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Ta et al.)

Consideration of position-specific features of the NFL concussion environment could enable improved risk mitigation through the design of position-specific helmets to improve self-protection as well as protection for the other player with whom the contact occurs. The purpose of this paper is to quantify position-specific features of scenarios resulting in concussions to NFL players, and the players they contact, by reviewing all game footage (broadcast and non-broadcast) over 4 seasons. Position-specific features were documented for 647 concussions in which a primary exposure could be visualized, including impact source, helmet impact location, activity, and the other player with whom the contact occurred. Findings include the over-representation of helmet-to-ground impacts to the rear of the quarterback's helmet, the high frequency of impacts to the side (upper) location of both concussed players and the players they contacted regardless of position, and distinct differences in the circumstances of concussions to cornerbacks and safeties. The study shows that some features of concussion scenarios are common to all positions, but several position-specific features exist and can inform the design of position-specific helmets for NFL players. [ABSTRACT FROM AUTHOR]

Head injury in contact sports can be mitigated, in part, through the enhancement of protective helmets that may be enabled by detailed finite element models. However, many contemporary helmet FE models include simplified geometry and material properties and have limited verification and validation over a representative range of impact conditions. To address these limitations, a detailed numerical model of a modern football helmet was developed, integrated with two headforms and assessed for 60 impact conditions with excellent ratings (0.79–0.93). The strain energy of the helmet components was investigated for eight impact locations and three impact speeds. In general, the helmet shell had the highest strain energy followed by the compression shocks; however, the facemask and straps had the highest strain energy for impacts involving the facemask. The component strain energy was positively correlated with the Head Injury Criterion, while the strain energy was not strongly correlated with the Brain Injury Criterion due to the dependence on rotational kinematics. This study demonstrated the applicability of a detailed football helmet finite element model to investigate a range of impact conditions and to assess energy distribution as a function of impact location and severity as a means of future helmet optimization. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effect of half-coverage helmet use in motorcycle accidents and to investigate the difference in neuron-specific enolase serum levels in helmeted and unhelmeted person who had sustained maxillofacial fractures during motorcycle accidents. A total of 48 subjects (22 helmeted and 26 unhelmeted) sustained maxillofacial fractures were divided into three parts: upper, middle, and lower facial. All patients were scored using the Glasgow Coma Scale upon arrival at the hospital. The most prevalent maxillofacial fracture site in helmeted group was the mid-face (40.9%) and the upper-middle-lower face (26.9%) in unhelmeted group. There was no statistical significant difference between neuron-specific enolase serum levels in helmeted group (11.52 mg/ml) compared to unhelmeted group (14.49 ng/ml) (p > 0.05). Half-coverage helmets provided motorcyclists with only limited protection in the head and facial areas. Unhelmeted motorcycle riders sustained comparable injuries compared to half-coverage helmet users.

A helmet used by motorcyclists is always of critical importance for the safety of the rider. A well-designed helmet should be able to absorb as much energy as possible and to diffuse it to the whole helmet during an impact. This project is intended to improve the design features with respect to thermal comfort of Helmet shell. The vital design features of helmets are extent of protection, ISO head form, and peripheral visions. Thermal discomfort can cause rider fatigue thereby reducing the overall concentration during driving. Various design concepts, such as adding ventilation holes, increasing clearance between the helmet shell and the head and covering the shell with reflective materials, are used to improve the thermal properties. The existing design of helmets does not account for the thermal comfort of the helmet shell into consideration so, a new design prototype is developed. At this stage, attention was also paid to structural safety, appearance and manufacturability. The thermal comforts that can be derived from this design are significantly improved over other commercially available helmets. [ABSTRACT FROM AUTHOR]

Traumatic brain injuries are among the most common severely disabling injuries in the United States. Construction helmets are considered essential personal protective equipment for reducing traumatic brain injury risks at work sites. In this study, we proposed a practical finite element modeling approach that would be suitable for engineers to optimize construction helmet design. The finite element model includes all essential anatomical structures of a human head (i.e. skin, scalp, skull, cerebrospinal fluid, brain, medulla, spinal cord, cervical vertebrae, and discs) and all major engineering components of a construction helmet (i.e. shell and suspension system). The head finite element model has been calibrated using the experimental data in the literature. It is technically difficult to precisely account for the effects of the neck and body mass on the dynamic responses, because the finite element model does not include the entire human body. An approximation approach has been developed to account for the effects of the neck and body mass on the dynamic responses of the head-brain. Using the proposed model, we have calculated the responses of the head-brain during a top impact when wearing a construction helmet. The proposed modeling approach would provide a tool to improve the helmet design on a biomechanical basis. [ABSTRACT FROM AUTHOR]

Objective: This study applied a human factors approach to snowsport resort systems to contribute to the understanding of the incidence and severity of pediatric snowsport head accelerations.Background: Previous research indicates low magnitude head accelerations are common among snowsport participants. This study adds to the knowledge of snowsport safety by measuring aspects of participants' snowsport behavior and linking this with head acceleration data.Method: School-aged students (n = 107) wore telemetry-fitted helmets and Global Positioning System (GPS) devices during snowsport activity. Data was collected over 159 sessions (total hours 701). Head accelerations recorded by the telemetry units were compared with GPS-generated data.Results: This study found speeds attained normally exceed the testing rating for which helmets are designed; lower rates of head accelerations compared to earlier studies and that when head accelerations did occur they were generally below the threshold for concussions.Conclusion: Pediatric snowsport head accelerations are rare and are generally of low magnitude. Those most at risk of a head acceleration >40 g were male snowboarders. Given the recorded speeds in first time participants, increased targeting of novice snowsport participants to encourage education about the use of protective equipment, including helmets, is warranted. Post event recall was not a good indicator of having experienced a head impact. Consideration should be given to raising the standard design speed testing for snowsport helmet protective devices to reflect actual snowsport behaviors. [ABSTRACT FROM AUTHOR]

As current determination of appropriate selection of energy absorbers is tedious and complicated, a data library and design template is developed, which hinges on the maximal energy density to stress ratio. This is the optimum point of any energy absorber, at which most energy is absorbed per unit volume at minimal reaction force per unit area. This optimum point is therefore defined by the optimal energy density and the optimal stress. From the former, the optimum absorber thickness is calculated considering the contact area and actual impact energy. From the latter, the peak deceleration is calculated considering the contact area and mass. Optimum thickness and peak deceleration are compared to the design constraints and unfeasible solutions are excluded. The remaining feasible solutions are ranked based on smallest optimum thickness, peak deceleration or absorber mass. Applications of the design template are exemplified by design cases. [ABSTRACT FROM AUTHOR]

Abstract: Ballistic helmet is a standard infantry equipment that provides ballistic protection from fragmenting to the head, temples, ear and neck of the wearer. This paper presents the study of the design of a locally used ballistic helmet, i.e. Personnel Armor System for Ground Troop (PASGT) type helmet, from ergonomic perspectives and the identification of potential risk areas of injury based on the current ballistic helmet design. Two quantitative assessment techniques are employed in the investigation. First, a set of questionnaires were distributed to the current users of the PASGT helmet. The result showed that the 54.8% of respondents experienced pain on the parietal (top) area of their head, which is a potential risk area of head injury. Second, an experiment with 10-mm thick sponge layer added to the interior part of the helmet was conducted to test its effect on the contact pressure between the head of the wearer and the medium size PASGT helmet while jogging on a treadmill at 8km/h for 180seconds. Mean of peak contact pressure with and without wearing the sponge of 2.5kPa and 2.6kPa, respectively, are obtained from the practical test. The maximum of peak contact pressure is found to be 3.6kPa with the sponge and 4.2kPa without the sponge. The results obtained in this study indicate that there are areas of discomfort interior to the PASGT helmet in contact with the wearer and that the discomfort can be minimized by appending a sponge layer to the frontal of the helmet. [Copyright &y& Elsevier]

Abstract: Traumatic brain injury (TBI) is generally considered as a signature injury of the current military conflicts, with costly and life-altering long-term effects. Hence, there is an urgent need to combat this problem by both gaining a better understanding of the mechanisms responsible for the blast-induced TBI and by designing/developing more effective head protection systems. In the present work, the blast-wave impact-mitigation ability of polyurea when used as a helmet suspension-pad material is investigated computationally. Towards that end, a combined Eulerian/Lagrangian fluid/solid transient non-linear dynamics computational analysis is carried out at two levels of blast peak overpressure: (a) one level corresponding to the unprotected-lung- injury-threshold; and (b) the other level associated with the corresponding 50% lethal dose (LD 50), i.e. with a 50% probability for lung-injury induced death. To assess the blast-wave impact-mitigation ability of polyurea, the temporal evolution of the axial stress and the particle (axial) velocity at different locations within the intra-cranial cavity are analyzed. The results are compared with their counterparts obtained in the case of a conventional foam suspension-pad material. This comparison showed that, the use of polyurea suspension pads is associated with a substantially greater reduction in the peak loading experienced by the brain relative to that observed in the case of the conventional foam. The observed differences in the blast-wave mitigation capability of the conventional foam and polyurea are next rationalized in terms of the differences in their microstructure and in their mechanical response when subjected to blast loading. [Copyright &y& Elsevier]

The ergonomic design of helmets is very important for those who wear them for long periods on the job; for example, construction workers and security personnel. A helmet's weight, stability, and ability to protect are especially important. According to our case study, fitting design according to head shape can significantly reduce the weight and enhance the stability of a helmet. The traditional helmet design process takes a long time, and is thus unsuitable for individually customized shape design. In this paper, a rapid preliminary design method for the helmet shell and a corresponding toolkit are introduced, taking advantage of three-dimensional (3D) anthropometric head scans. A 3D head model is first generated from the 3D head scan of the intended user or representative user of an intended population group. Then a semi-parametric surface modelling tool is applied to quickly generate the helmet shell by simply inputting several parameters related to helmet protection, size, and shape requirements and adjusting several key curves. In a case study, the new design by the proposed method and the existing design by the traditional method were compared with regard to weight, centroid, and moments of inertia to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Elite cricketers believe that the use of helmets may help to reduce anxiety when facing fast bowling although they risk visual impairment in time-stressed circumstances. This study aimed to determine the effects of helmet design and bowling speed on heart rate (HR), anxiety arid batting performance. Elite batsman (n=12) faced 20 deliveries from a bowling machine at slow (21 m s−1) and fast (42ms−1 ) speeds under three different headgear conditions— helmet with bars, visorless helmet and no-helmet. State measures of anxiety were taken before and after each batting condition by questionnaire. Heart rate (HR) was monitored throughout the test session. Batting performance was filmed and rated for quality by expert coaches on the basis of bat contact, foot movement, element of attack and timing. Repeated measures analysis of variance revealed no significant differences in HR or performance between helmet conditions. Batting performance was significantly better against slow bowling than fast (p<0·01) and no significant differences were found for HR between the bowling speeds. No significant correlations were found between HR, performance and state anxiety scores but there was a significant negative relationship between perceived quality of performance and post-batting A-state (r= −0·62; p<0·05) in the barred helmet condition only. It is concluded that elite cricketers experienced little change in the level of performance-related anxiety when wearing helmets of varying designs, even when faced with bowling of considerable speed. There was no evidence of performance decrements when wearing helmets with bars and visors which suggests that the use of maximum protection against the possibility of facial damage does not seriously affect the batsman's ability to track and play the ball. [ABSTRACT FROM PUBLISHER]

In this study, a novel expandable bicycle helmet, which integrates an airbag system into the conventional helmet design, was proposed to explore the potential synergetic effect of an expandable airbag and a standard commuter-type EPS helmet. The traumatic brain injury mitigation performance of the proposed expandable helmet was evaluated against that of a typical traditional bicycle helmet. A series of dynamic impact simulations on both a helmeted headform and a representative human head with different configurations were carried out in accordance with the widely recognised international bicycle helmet test standards. The impact simulations were initially performed on a ballast headform for validation and benchmarking purposes, while the subsequent ones on a biofidelic human head model were used for assessing any potential intracranial injury. It was found that the proposed expandable helmet performed admirably better when compared to a conventional helmet design-showing improvements in impact energy attenuation, as well as kinematic and biometric injury risk reduction. More importantly, this expandable helmet concept, integrating the airbag system in the conventional design, offers adequate protection to the cyclist in the unlikely case of airbag deployment failure.

The aim of this study was to assess the effect of half-coverage helmet use in motorcycle accidents and to investigate the difference in neuron-specific enolase serum levels in helmeted and unhelmeted person who had sustained maxillofacial fractures during motorcycle accidents. A total of 48 subjects (22 helmeted and 26 unhelmeted) sustained maxillofacial fractures were divided into three parts: upper, middle, and lower facial. All patients were scored using the Glasgow Coma Scale upon arrival at the hospital. The most prevalent maxillofacial fracture site in helmeted group was the mid-face (40.9%) and the upper-middle-lower face (26.9%) in unhelmeted group. There was no statistical significant difference between neuron-specific enolase serum levels in helmeted group (11.52 mg/ml) compared to unhelmeted group (14.49 ng/ml) (p > 0.05). Half-coverage helmets provided motorcyclists with only limited protection in the head and facial areas. Unhelmeted motorcycle riders sustained comparable injuries compared to half-coverage helmet users. [ABSTRACT FROM AUTHOR]