Head Impact Research Articles

Vehicle Collision Analysis of the Reinforced Concrete Barriers Installed on Bridges Using Node-Independent Model

This paper focuses on improving vehicle collision simulations using finite element analysis (FEA) to examine interactions between reinforced concrete barriers and bridge decks. Three scenarios are explored: treating the barrier as a rigid body, analyzing reinforcement with a fixed base, and including the bridge deck’s cantilever portion beneath the barrier. Except for the rigid body model, a node-independent approach models the complex interactions between reinforcement and concrete in barriers on the bridge deck. This study evaluates barrier strength, occupant risk, and post-collision vehicle safety. Strength is assessed by examining stress in reinforcement and concrete, while occupant risk is measured using Theoretical Head Impact Velocity (THIV) and Post-impact Head Deceleration (PHD). Vehicle trajectory during collisions is also analyzed for stability. The results show significant differences in stress distribution and failure patterns when the bridge deck is considered compared to scenarios without it. Occupant risk evaluations suggest more flexible responses when the bridge deck is included. However, vehicle trajectory post-collision showed no significant differences across scenarios. These findings indicate that modeling efficiency varies based on evaluation criteria, suggesting a more realistic and effective approach for assessing barriers on bridges.

Role of the upper limb in limiting head impact during laboratory-induced falls in at fall-risk older adults.

Fall-related head impact is the leading cause of traumatic brain injury in older adults. There is limited understanding of factors related to fall-related head impact. This investigation examined characteristics of upper limb movements during standing-height falls and examined their association with fall-related head impact in older adults at risk for falls. Older adults (n=29) at risk for fall-related injuries underwent experimentally induced falls in multiple directions (backwards and sideways). To characterize the upper limb movements and their association with head impact, a standardized analysis tool was used to analyze a total of 164 video-recorded falls. The association between upper limb movements (and their characteristics) and head impact was analyzed through logistic regression. Nearly 80% of falls involved upper limb movements. Absence of upper limb movements significantly increased head impact odds by approximately 4-fold. The odds of head impact were reduced in falls with energy absorption at the forearm (0.013-fold) and upper arm (0.018-fold), compared to falls without upper limb energy absorption. Backwards falls showed significantly higher odds of head impact (more than 4-fold). Upper limb movements are common during fall descent and are associated with lower odds of experiencing head impact. Energy absorption with the upper limb seems to be an important protective mechanism. Future work should explore if these movements can be augmented with targeted training.

Holohemispheric Hemorhhage in Infantile Acute Subdural Hematoma: Serial Neuroimaging Analysis

Background: An acute subdural hematoma (ASDH) in infants without any external sign of trauma is differently recognized as shaken baby syndrome (SBS) / abusive head trauma (AHT) in the United States or as infantile acute subdural hematoma (IASDH) due to minor head trauma in Japan. The present case report aimed to demonstrate that IASDH can occur after a mild head impact if the dural border cell layer is disrupted in an infant with cranio-cerebral disproportion (CCD). Case description: A 5-month-old, male patient fell from a baby bed and struck his occiput against a mat. He began to cry and soon thereafter demonstrated signs of altered consciousness. He was taken to a pediatric hospital where computed tomography (CT) revealed a thin subdural hematoma (SDH) surrounding the entire right cerebral hemisphere. Fundoscopy found a right-sided retinal hemorrhage. Magnetic resonance imaging (MRI) on hospital day 4 revealed a thin, high-intensity ASDH surrounding the entire, cerebral convexity on the right side. In addition, benign enlargement of the subarachnoid space (BESS) and large sylvian fissure (LSF) were noted. On hospital day 12 and 18, follow-up MRI revealed a residual SDH with minimal reduction. The patient had an uneventful clinical course and met all the normal, developmental milestones as of his current age of 3 years. Conclusion: The present case is invaluable because it demonstrates that ASDH can occur as a result of a mild, occipital impact. Particularly relevant here is the thin, holohemispheric appearance of the hematoma on neuroimaging studies, which has been suitably termed, holohemispheric subdural hematoma (HHSDH). Also noteworthy is the long-term presence of the HHSDH with minimal reduction of the SDH. The HHSDH may be caused by entrapment of the hematoma in the dural border cell layer in the absence of any communication with the surrounding structures.

A comparison of head impact characteristics during elite men’s Rugby Union fifteens and sevens match play

Different forms of rugby may pose distinct risks to head injury. Video of rugby match footage was analyzed using head impact magnitude, frequency, and time interval for 15s and 7s athletes. Impacts were reconstructed in laboratory, and finite element modeling was used to estimate maximum principal strain. No difference was found in impact frequency or time interval between the two forms. Significantly more head impacts of higher severity levels were documented during 7s. These findings provide objective comparisons between 7s and 15s which may guide risk mitigation strategies in managing brain trauma for specific forms of rugby.

Characterizing the Effects of Concussion and Head Impact Exposure: Design, Methods, and Participant Traits of the CARE 2.0 Study.

This article describes the design, methods, and participant characteristics of the second phase of the Concussion Assessment, Research, and Education (CARE) Consortium study ("CARE 2.0") of the effects of concussion and repetitive head impact exposure on neuropsychiatric health. The authors conducted a prospective multisite observational study of male and female collegiate athletes and military service academy cadets and midshipmen participating in the CARE study. Participants were assessed at three time points: undergraduate baseline (UB), before departure from university or service academy (exit), and up to 6 years following graduation (postgrad) via an online battery of brain health assessments. Participant characteristics were compared across the three time points and four levels of head impact exposure. A total of 4,643 participants completed the exit assessment, and 3,981 completed the postgrad assessment. Relative to the UB assessment cohort, the exit and postgrad assessment cohorts differed with respect to the percentage of women, baseline Wechsler Test of Adult Reading scores, National Collegiate Athletic Association division category, sport contact level, and number of previous concussions. The median standardized difference across balancing variables, assessment time points, and degree of head impact exposure was 0.12 (with 90% of effect sizes ≤0.29). Although there were some statistically significant differences between participants across assessments, the effect sizes were modest, and overall the data suggest that the exit and postgrad cohorts reflect the characteristics of the baseline cohort. The CARE study design and its large, richly characterized sample provide an opportunity to answer important questions about cumulative and persistent effects of concussion and repetitive head impact exposure on neuropsychiatric health.

Impact of Head and Neck Multidisciplinary Clinic on Treatment Package Time During 2 Years of the COVID-19 Pandemic: A Single-Institution Experience.

Prolongation of treatment package time is strongly associated with inferior oncologic outcomes. We examine the effect of creation of a multidisciplinary head and neck clinic on treatment package times. This was a retrospective cohort study evaluating treatment package time in patients receiving adjuvant radiation through a multidisciplinary clinic compared with standard clinics at a single academic institution between 7/31/2020 and 7/31/2022. Adjuvant radiotherapy was administered to 23 patients in multidisciplinary clinic, 68 patients in standard clinic and 17 patients in satellite clinics. Patients seen in multidisciplinary clinic began adjuvant radiation sooner (median 35 vs 41 vs 48 days, p=0.01) with more compact treatment package times (median 78 vs 84 vs 86 days, p=0.003). Nine patient (13%) in standard clinics and 4 patients (24%) at the satellite clinics had adjuvant treatment package times exceeding 100 days. No patient seen in multidisciplinary clinic had treatment package times exceeding 100 days. Colocalization of radiation oncology and otolaryngology care in multidisciplinary clinic substantially improved time to postoperative radiotherapy and treatment package times. This is likely due to the identification of patients requiring adjuvant radiation earlier in their clinical presentation which in turn allowed for advanced planning and minimization of delays in initiation of adjuvant radiation.

Elucidating Mechanisms of Chronic Traumatic Encephalopathy (CTE); A Systematic Review of the Literature.

Chronic traumatic encephalopathy (CTE) is a progressive neurodegeneration that can be widely distributed throughout the brain due to accumulation of neuropathologic lesions following exposure to repetitive head impact (RHI) causing concussions or sub-concussive traumatic brain injury (TBI). Populations at risk include military personnel and contact sports athletes. A neuropathological severity staging system has been developed based on lesion complexity.

Understanding beliefs and perceptions of parents, coaches, and organizational leaders toward non-concussive head impact exposure in youth American football

Understanding beliefs and perceptions of parents, coaches, and organizational leaders toward non-concussive head impact exposure in youth American football

Comparing frequency and maximum principal strain of head impacts for U15 ice hockey leagues with standard and modified body contact rules

Brain trauma in bodychecking ice hockey is of concern for youth participants, as it presents unique risks compared to the non-bodychecking version of the sport. This study compared head impact frequency and magnitude between two ice hockey leagues with different body contact rules in the U15 age division: AAA (standard bodychecking) and M15 Minor (modified body contact rules). Video analysis of 16 games per league revealed no significant overall diference in impact frequency. M15 Minor players sustained significantly more head-to-head (14 to 2) impacts and AAA players sustained significantly more head-to-glass (18 to 7) and punch impacts (4 to 0). Laboratory reconstructions and finite element modeling were used to determine impact magnitude as maximum principal strain (MPS) and categorized from very low to very high. Higher impact frequency of very low MPS head impact events were observed for M15 Minor (61 to 51). The findings from this study highlight that this method of modifying body contact rules in U15 hockey did not result in lower levels of brain trauma, rather it presented unique brain trauma mechanisms compared to bodychecking.

Cavum Septum Pellucidum in Former American Football Players: Findings From the DIAGNOSE CTE Research Project.

Exposure to repetitive head impacts (RHI) is linked to the development of chronic traumatic encephalopathy (CTE), which can only be diagnosed at post-mortem. The presence of a cavum septum pellucidum (CSP) is a common finding in post-mortem studies of confirmed CTE and in neuroimaging studies of individuals exposed to RHI. This study examines CSP in living former American football players, investigating its association with RHI exposure, traumatic encephalopathy syndrome (TES) diagnosis, and provisional levels of certainty for CTE pathology. Data from the DIAGNOSE CTE Research Project were used to compare the presence and ratio of CSP in former American football players (n = 175), consisting of former college (n = 58) and former professional players (n = 117), and asymptomatic unexposed controls without RHI exposure (n = 55). We further evaluated potential associations between CSP measures and cumulative head impact index (CHII) measures (frequency, linear acceleration, and rotational force), a TES diagnosis (yes/no), and a provisional level of certainty for CTE pathology (suggestive, possible, and probable). Former American football players exhibited a higher CSP presence and ratio than unexposed asymptomatic controls. Among player subgroups, professional players showed a greater CSP ratio than former college players and unexposed asymptomatic controls. Among all football players, CHII rotational forces correlated with an increased CSP ratio. No significant associations were found between CSP measures and diagnosis of TES or provisional levels of certainty for CTE pathology. This study confirms previous findings, highlighting a greater prevalence of CSP and a greater CSP ratio in former American football players compared with unexposed asymptomatic controls. In addition, former professional players showed a greater CSP ratio than college players. Moreover, the relationship between estimates of CHII rotational forces and CSP measures suggests that cumulative frequency and strength of rotational forces experienced in football are associated with CSP. However, CSP does not directly correlate with TES diagnosis or provisional levels of certainty for CTE, indicating that it may be a consequence of RHI associated with rotational forces. Further research, especially longitudinal studies, is needed for confirmation and to explore changes over time.

The Intersection Of Sleep And Head Impacts In Division I Collegiate Football Players: A Pilot Study

The Intersection Of Sleep And Head Impacts In Division I Collegiate Football Players: A Pilot Study

Studying Contact Replays: Investigating Mechanisms, Management and Game Exposures (SCRIMMAGE) for brain health in the Australasian National Rugby League: a protocol for a database design

Concussions in contact sports are challenging for athletes, health professionals and sporting bodies to prevent, detect and manage. Design of interventions for primary prevention, early recognition of concussion and continuing...

Sensitivity And Agreement Between Head Impact Monitoring Devices In American Football

Sensitivity And Agreement Between Head Impact Monitoring Devices In American Football

Characteristics Of Play Associated With Head Impact Severity During Tackling In Youth Football

Characteristics Of Play Associated With Head Impact Severity During Tackling In Youth Football

Does Neck Strength Predict Repetitive Head Impacts In Youth Football Athletes?

Does Neck Strength Predict Repetitive Head Impacts In Youth Football Athletes?

Spontaneous Cardiovagal Baroreflex Sensitivity Following A Bout Of Subconcussive Head Impacts Is Not Altered

Spontaneous Cardiovagal Baroreflex Sensitivity Following A Bout Of Subconcussive Head Impacts Is Not Altered

Head Impact Monitoring In Youth Football: Comparing Measurements From Helmet-Mounted Sensors And Instrumented Mouthguards

Head Impact Monitoring In Youth Football: Comparing Measurements From Helmet-Mounted Sensors And Instrumented Mouthguards

Potential of Soft-Shelled Rugby Headgear to Lower Regional Brain Strain Metrics During Standard Drop Tests

BackgroundThe growing concern for player safety in rugby has led to an increased focus on head impacts. Previous laboratory studies have shown that rugby headgear significantly reduces peak linear and rotational accelerations compared to no headgear. However, these metrics may have limited relevance in assessing the effectiveness of headgear in preventing strain-based brain injuries like concussions. This study used an instantaneous deep-learning brain injury model to quantify regional brain strain mitigation of rugby headgear during drop tests. Tests were conducted on flat and angled impact surfaces across different heights, using a Hybrid III headform and neck.ResultsHeadgear presence generally reduced the peak rotational velocities, with some headgear outperforming others. However, the effect on peak regional brain strains was less consistent. Of the 5 headgear tested, only the newer models that use open cell foams at densities above 45 kg/m3 consistently reduced the peak strain in the cerebrum, corpus callosum, and brainstem. The 3 conventional headgear that use closed cell foams at or below 45 kg/m3 showed no consistent reduction in the peak strain in the cerebrum, corpus callosum, and brainstem.ConclusionsThe presence of rugby headgear may be able to reduce the severity of head impact exposure during rugby. However, to understand how these findings relate to brain strain mitigation in the field, further investigation into the relationship between the impact conditions in this study and those encountered during actual gameplay is necessary.

We Should Celebrate, Not Censor, Learning From Epidemiologic History.

The controversy over whether repeated head impact (RHI)-a feature of occupations including professional contact sports, military service, firefighting, and logging-can cause the neurodegenerative disease now known as CTE (chronic traumatic encephalopathy) has thrust many positive epidemiologic studies into the spotlight. Various skeptics who dispute that the relationship is strong and causal continue to raise objections to these studies and their interpretation. The arguments these skeptics use remind other observers of many past sagas of "manufactured doubt," particularly the history of attempts to cast doubt on the propensity of tobacco products to cause lung cancer. A recent article in the Journal of Science and Medicine in Sport3 complained that drawing the parallel between RHI and cigarettes is unhelpful, concluding that "the time for politically motivated analogies has now passed." This author disagrees, and explains in detail 2 scientific aspects of risk assessment and management that make the analogy apt and instructive for the future. In particular, I argue that the problem of "manufactured doubt" here is two-fold: it relies on various fallacies of reasoning discussed herein, but more importantly, it seeks to divert and delay the utilitarian imperative-while we grope toward the ever-elusive certainty, there are many low-regret actions we can and should take on the basis of persuasive signals of harm.

Patient-reported outcome measures and physical function following head and neck lymphedema - a systematic review.

Head and neck cancer (HNC) treatments often lead to significant morbidity, including lymphedema. This systematic review aims to comprehensively explore the prevalence and impact of head and neck lymphedema (HNL) following treatment. A systematic literature search was conducted up to September 2023. Studies evaluating HNL prevalence, associated factors, impact, patient-reported outcomes (PROMs), and physical assessments were included. Methodological quality assessment was performed, and data were synthesised narratively. Twelve studies met the inclusion criteria, with methodological quality ranging from moderate to high. Internal lymphedema prevalence was consistently higher than external lymphedema, with varying rates attributed to treatment modalities and assessment methods. PROMs such as the Lymphedema Symptom Intensity and Distress-Head and Neck and physical assessments including Patterson's Rating Scale were commonly utilised. HNL significantly impacted quality of life and physical function, with reported symptoms including discomfort, tightness, swallowing difficulties, and psychological distress. HNL is a common sequela of HNC treatment with significant implications for individuals' QoL. Standardised assessment protocols and tailored interventions are needed to address the needs of individuals with HNL and improve overall outcomes. This systematic review highlights a significant prevalence of lymphedema, particularly internal lymphedema in the larynx and pharynx, following treatment. Swallowing difficulties, nutritional issues, anxiety, depression, and body image concerns were associated with both internal and external lymphedema. The impact on quality of life is substantial, with survivors experiencing physical symptoms and psychosocial challenges, emphasising the importance of integrated care approaches tailored to both aspects of well-being.