Analysis of loading curve characteristics on the production of brain deformation metrics

Post, Andrew; Walsh, Evan S; Hoshizaki, T. Blaine; Gilchrist, Michael D.

doi:10.1177/1754337112449420

Cited by 13 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order for the tested ice hockey goaltender helmets to influence the level of MPS produced from puck impacts the material and design considerations may need to consider other aspects of the acceleration curves. Similar findings have been reported for ice hockey skater helmets 47,52 and brain injury simulations 43,45,65 which would support these results.…”

Section: Fallssupporting

confidence: 91%

Comparison of Ice Hockey Goaltender Helmets for Concussion Type Impacts

et al. 2018

Self Cite

View full text Add to dashboard Cite

Concussions are among the most common injuries sustained by ice hockey goaltenders and can result from collisions, falls and puck impacts. However, ice hockey goaltender helmet certification standards solely involve drop tests to a rigid surface. This study examined how the design characteristics of different ice hockey goaltender helmets affect head kinematics and brain strain for the three most common impact events associated with concussion for goaltenders. A NOCSAE headform was impacted under conditions representing falls, puck impacts and shoulder collisions while wearing three different types of ice hockey goaltender helmet models. Resulting linear and rotational acceleration as well as maximum principal strain were measured for each impact condition. The results indicate that a thick liner and stiff shell material are desirable design characteristics for falls and puck impacts to reduce head kinematic and brain tissue responses. However for collisions, the shoulder being more compliant than the materials of the helmet causes insufficient compression of the helmet materials and minimizing any potential performance differences. This suggests that current ice hockey goaltender helmets can be optimized for protection against falls and puck impacts. However, given collisions are the leading cause of concussion for ice hockey goaltenders and the tested helmets provided little to no protection, a clear opportunity exists to design new goaltender helmets which can better protect ice hockey goaltenders from collisions.

show abstract

Section: Fallssupporting

confidence: 91%

Comparison of Ice Hockey Goaltender Helmets for Concussion Type Impacts

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…To appropriately reconstruct an event, the following five parameters were determined and categorized: velocity, location, orientation, effective mass, and compliance. These parameters create unique head kinematic motions that subsequently influence the magnitude of neural tissue loading and physical responses 46,47,[76][77][78][79][80][81][82][83][84][85] . Inbound velocity, and head location and orientation were obtained during video analysis; effective mass and compliance were approximated using known measurements and available literature [86][87][88] .…”

Section: Methodsmentioning

confidence: 99%

A novel repetitive head impact exposure measurement tool differentiates player position in National Football League

Karton

Hoshizaki

Gilchrist

2020

Sci Rep

View full text Add to dashboard Cite

American-style football participation poses a high risk of repetitive head impact (RHI) exposure leading to acute and chronic brain injury. The complex nature of symptom expression, human predisposition, and neurological consequences of RHI limits our understanding of what constitutes as an injurious impact affecting the integrity of brain tissue. Video footage of professional football games was reviewed and documentation made of all head contact. Frequency of impact, tissue strain magnitude, and time interval between impacts was used to quantify RHI exposure, specific to player field position. Differences in exposure characteristics were found between eight different positions; where three unique profiles can be observed. Exposure profiles provide interpretation of the relationship between the traumatic event(s) and how tissue injury is manifested and expressed. This study illustrates and captures an objective measurement of RHI on the field, a critical component in guiding public policy and guidelines for managing exposure.Various levels of impact severity associated with head injury have been studied for over a century where knowledge and reporting reflected current periods' public concern and environmental context 1 . The scientific community, medical sectors and regulatory authorities have been working for decades to unravel the complexity of head injury in sport, most predominantly the definition, identification, and treatment of concussions. There were obvious challenges associated with the ambiguous nature and presentation of what is regarded as a tissue 'injury' 2,3 . Inconsistencies in symptom expression and prediction, and human variability in predisposition limit the precision in defining the relationship between the traumatic event(s) and injury. Despite numerous reports describing the implications of the acute and chronic effects of single and repeated sub-concussive and concussive blows to the head 1 , only recently have exposure to repetitive head impacts (RHI) in contact sports become a real concern, and this concern has become relevant to researchers, neurologists, clinicians and athletic professionals alike. The high profile sport, American-style football (ASF), has received increasing attention amongst researchers who believe that this population will help establish a better understanding of the consequences and management of RHI.Measuring head injury in ASF solely on the basis of immediate signs and symptoms has proven to be insufficient in capturing the spectrum of tissue injury 4,5 . Moreover, as individuals recover from the clinical expression of symptoms, the assumption that neurobiological recovery has also occurred is also likely to be inaccurate 6,7 . A more sophisticated understanding that now prevails considers the time course of neurobiological recovery and the mental health consequences of being exposed to RHI. Oliver and colleagues 8 report that blood concentrations of axonal injury biomarkers in college football starters remain elevated even 9 weeks post season. The scientific de...

show abstract

“…However, this empirical rule was questioned for applicability in head injury models, where reasonable displacements were achieved when hourglass energy was much higher (200-300% of internal energy), but nonphysical nodal displacements occurred when the energy ratio was within the recommended level 35 . In addition, the different options for hourglass energy control (e.g., enhanced hourglass control 34 , relax stiffness control 29 , or no control 28 ) further amounted to significant confusion among research groups that led to substantial model inconsistencies.…”

Section: Introductionmentioning

confidence: 99%

Mesh Convergence Behavior and the Effect of Element Integration of a Human Head Injury Model

Zhao

2018

Ann Biomed Eng

View full text Add to dashboard Cite

Numerous head injury models exist that vary in mesh density by orders of magnitude. A careful study of the mesh convergence behavior is necessary, especially in terms of strain most relevant to brain injury. To this end, as well as to investigate the effect of element integration on simulated strains, we re-meshed the Worcester Head Injury Model (WHIM) at five mesh densities (~7.2-1000 k hexahedral elements of the brain). Results from explicit dynamic simulations of three cadaveric impacts and an in vivo head rotation were compared. First, scalar metrics of the whole brain only considering magnitude were used, including peak maximum principal strain and population-based median strain. They were further extended to deep white matter regions and the entire brain elements, respectively, to form two "response vectors" to account for both magnitude and distribution. Using benchmark enhanced full-integration elements (C3D8I), a minimum of 202.8 k brain elements was necessary to converge for response vectors of the deep white matter. This model was further used to simulate with reduced integration (C3D8R). We found that hourglass energy higher than the rule of thumb (e.g., up to 44.38% vs. <10% of internal energy) was necessary to maintain comparable strain relative to C3D8I. Based on these results, it is recommended that a head injury model should have an average element size of no larger than 1.8 mm for the brain. C3D8R formulation with relax stiffness hourglass control using a high scaling factor (e.g., 15) is also recommended to achieve sufficient accuracy without substantial computational cost.

show abstract

Analysis of loading curve characteristics on the production of brain deformation metrics

Cited by 13 publications

References 26 publications

Comparison of Ice Hockey Goaltender Helmets for Concussion Type Impacts

Comparison of Ice Hockey Goaltender Helmets for Concussion Type Impacts

A novel repetitive head impact exposure measurement tool differentiates player position in National Football League

Mesh Convergence Behavior and the Effect of Element Integration of a Human Head Injury Model

Contact Info

Product

Resources

About