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Current equestrian standards employ a drop test to a rigid steel anvil. However, falls in equestrian sports often result in impacts with soft ground. The purpose of this study was to compare head kinematics and brain tissue response associated with surfaces impacted during equestrian accidents and corresponding helmet certification tests. A helmeted Hybrid III headform was dropped freely onto three different anvils (steel, turf and sand) at three impact locations. Peak linear acceleration, rotational acceleration and impact duration of the headform were measured. Resulting accelerations served as input into a three-dimensional finite element head model, which calculated Maximum principal strain (MPS) and von Mises stress (VMS) in the cerebrum. The results indicated that impacts to a steel anvil produced peak head kinematics and brain tissue responses that were two to three times greater than impacts against both turf and sand. Steel impacts were less than half the duration of turf and sand impacts. The observed response magnitudes obtained in this study suggest that equestrian helmet design should be improved, not only for impacts to rigid surfaces but also to compliant surfaces as response magnitudes for impacts to soft surfaces were still within the reported range for concussion in the literature. [ABSTRACT FROM AUTHOR]

This study examined the effects and interaction of four primary impact parameters (impact velocity, angle of impact relative to the ground, ground compliance and helmet impact location) on head kinematics and brain tissue response for falls that are most commonly associated with equestrian sports. A helmeted headform was subject to parametric tests using a rail guided launcher at three impact velocities (6, 9 and 12 m/s), four angles of incidence (15°, 30°, 45° and 60°), three ground compliance levels (High, Medium and Low) and three helmet locations (front, front-boss and rear-boss). Head kinematics were obtained from the headform and a finite element model was used to estimate brain tissue response. Velocity and angle had the largest effects on the risk of concussion, as measured by head kinematics and brain tissue response, while compliance and location were less influential. Interactions such as angle and compliance were found to greatly influence the risk of concussion. These findings suggest that an increased ground compliance can decrease linear acceleration and Head Injury Criterion (HIC) but not necessarily decrease rotational kinematics and brain tissue response. Consequently, the use of technological designs to attenuate rotational acceleration and decouple the helmet from that of the head may provide better safety than simply the addition of extra protective layers to the ground or a helmet liners. [ABSTRACT FROM AUTHOR]

Goaltenders in the sport of ice hockey are at high risk for concussions from falls to the ice, player collisions and puck impacts. However, current methods used to certify helmets only consider head accelerations for drop tests which may not describe all common injury mechanisms relating to concussion. The purpose of this study was to describe the characteristics of 3 events associated with concussions for ice hockey goaltenders. A helmeted medium National Operating Committee on Standards for Athletic Equipment (NOCSAE) headform was impacted under conditions representing 3 injury events. Three impact locations' velocities were selected for each event based on video analysis of real-world concussive events. Peak resultant linear acceleration, rotational acceleration and rotational velocity of the headform were measured. The University College Dublin Brain Trauma Model (UCDBTM) was used to calculate maximum principal strain (MPS) and von Mises stress in the cerebrum. Each impact event produced a unique dynamic response and brain stress and strain values. This demonstrates that a single impact event (i.e. falls) cannot adequately describe all impact events. As a result, impact protocols which assess multiple impact events such as the protocol described in this study should be used to evaluate ice hockey goaltender masks. [ABSTRACT FROM AUTHOR]

The performance of equestrian helmets to protect against brain injuries caused by fall impacts against compliant surfaces such as turf has not been studied widely. We characterize the kinematic response of simulated fall impacts to turf through field tests on horse racetracks and laboratory experiments. The kinematic response characteristics and ground stiffness at different going ratings (GRs) (standard measurement of racetrack condition) were obtained from 1m and 2m drop tests of an instrumented hemispherical impactor onto a turf racetrack. The "Hard" rating resulted in higher peak linear accelerations and stiffness, and shorter impact durations than the "Soft" and "Heavy" ratings. Insignificant differences were found among the other GRs, but a strong overall relationship was evident between the "going rating" and the kinematic response. This relationship was used to propose a series of three synthetic foam anvils as turf surrogates in equestrian falls corresponding to ranges of GRs of (i) heavy-soft (H-S), (ii) good-firm (G-F), and (iii) firm-hard (F-H). Laboratory experiments consisted of a helmeted headform being dropped onto natural turf and the turf surrogate anvils using a monorail drop rig. These experiments revealed that the magnitudes and durations of the linear and rotational accelerations for helmeted impacts to turf/turf surrogates were similar to those in concussive sports falls and collisions. Since the compliance of an impacted surface influences the dynamic response of a jockey's head during a fall impact against the ground, it is important that this is considered during both accident reconstructions and helmet certification tests. [ABSTRACT FROM AUTHOR]

There is significant difference between the loading conditions used to certify equestrian helmets and the environment in which they are commonly used. This may affect their ability to provide adequate protection against head injury during a riding accident. The efficacy of helmet performance under real-world riding conditions can be judged by examining physical damage to the helmet during an impact, along with details of any head injury that may have been sustained by the rider. The present study considered the influence of different impact events on helmet damage sustained during real-world equestrian racing and eventing accidents. Video analysis of the accidents and assessment of the corresponding helmets allowed helmet damage to be matched to impacts. From a total of 1,119 accident videos and 218 inspected helmets, there was a total of 18 cases for which both the helmet and unobstructed video views of the accident sequence were available, along with details of any injuries sustained by the rider. All 18 cases involved the riders falling from their horses and impacting their heads against the turf. For 7 of the 18 cases, head impacts occurred in which a rider's head was also either kicked, crushed, or stomped on by a horse: those subsequent impacts led to significant helmet damage, suggesting that the helmets provided protection for the riders during those secondary and tertiary impacts. Surprisingly, 11 of the 18 cases involved only a fall for which none of the helmets had any evident damage, despite 6 of those cases involving diagnosed concussions and 1 hematoma. This indicates that traumatic brain injury can occur in equestrian sports even while the rider wears a helmet, which suggests that there is scope to further improve the ability of equestrian helmets to protect against concussion when riders fall and impact their head against turf. [ABSTRACT FROM AUTHOR]

Concussions are among the most common injuries sustained by goaltenders. Concussive injuries are characterized by impairment to neurological function which can affect many different brain regions. Understanding how different impact loading conditions (event type and impact site) affect the brain tissue response may help identify what kind of impacts create a high risk of injury to specific brain regions. The purpose of this study was to examine the influence of different impact conditions on the distribution of brain strain for ice hockey goaltender impacts. An instrumented headform was fitted with an ice hockey goaltender mask and impacted under a protocol which was developed using video analysis of real world ice hockey goaltender concussions for three different impact events (collision, puck, and fall). The resulting kinematic response served as input into the University College Dublin Brain Trauma Model (UCDBTM), which calculated maximum principal strain (MPS) in the cerebrum. Strain subsets were then determined and analyzed. Resulting peak strains (0.124-0.328) were found to be within the range for concussion reported in the literature. The results demonstrated that falls and collisions produced larger strain subsets in the cerebrum than puck impacts which is likely a reflection of longer impact duration for falls and collisions than puck impacts. For each impact event, impact site was also found to produce strain subsets of varying size and configuration. The results of this study suggest that the location and number of brain regions which can be damaged depend on the loading conditions of the impact. [ABSTRACT FROM AUTHOR]