Head Impact Research Articles

Abstract Repetitive head impacts are common in contact and collision sports and are linked to structural brain changes and an elevated risk of neurodegenerative diseases such as Chronic Traumatic Encephalopathy. Identifying early in vivo structural markers remains challenging. Although diagnosis currently requires postmortem confirmation, clinical symptoms, including cognitive impairment and behavioral changes, are reflected in the diagnosis of Traumatic Encephalopathy Syndrome. These symptoms align with dysfunction in key brain regions—amygdala, hippocampus, and thalamus—which support memory, emotion, and behavior, and commonly show tau pathology in Chronic Traumatic Encephalopathy. This study uses shape analysis to examine structural differences in these regions between former American football players and unexposed asymptomatic controls and evaluates the influence of age, head impact exposure, and clinical diagnosis on brain structure. We analyzed brain morphology in former American football players (n = 163) and unexposed, asymptomatic controls (n = 53). Structural segmentation was performed with FreeSurfer 7.1, and the shape analysis pipeline was used to generate subregional reconstructions. Vertex-level morphometry, based on the logarithm of the Jacobian determinant and radial distance, quantified local surface area dilation and thickness. Group differences were examined with covariate-adjusted linear regression models contrasting football players and controls, as well as participants with and without a Traumatic Encephalopathy Syndrome diagnosis. Partial correlations examined the influence of age, age of first football exposure, and cumulative head impact index metrics, including frequency, linear acceleration, and rotational force. Models were adjusted accordingly for age, body mass index, education, race, imaging site, apolipoprotein ε4 status, and total intracranial volume. Former football players exhibited bilateral surface area contractions in the hippocampus and amygdala, along with reduced amygdala thickness, compared to controls. Older age was associated with widespread surface contractions and thinning across all regions, except for preserved thickness in the left hippocampus. An earlier age of first exposure to football correlated with surface contractions in the thalamus and left hippocampus. Greater cumulative linear acceleration was linked to bilateral hippocampal surface contractions and reduced thickness in the left thalamus, while greater rotational force exposure was associated with hippocampal thinning. No significant structural differences were found between players with and without a diagnosis of Traumatic Encephalopathy Syndrome. These findings extend volume-based research by revealing localized alterations in surface area dilation and thickness and emphasize the roles of age and repetitive head impact exposure in long-term brain changes.

Abstract: Construction sites remain among the most dangerous workplaces, where a large proportion of accidents result from head injuries, electrocution, and impact with moving or falling objects. Ensuring that workers consistently wear Personal Protective Equipment (PPE) such as helmets, vests, gloves, masks, and safety shoes is therefore essential. Traditionally, safety compliance is enforced through manual supervision or sensor-based systems, both of which have limited real-time capabilities and scalability. To overcome these limitations, this study introduces an artificial intelligence driven vision based PPE monitoring system designed for automated detection and compliance analysis. The proposed approach employs a lightweight YOLOv8 model integrated with preprocessing and postprocessing pipelines, a FastAPI based backend, and an interactive web dashboard for live visualization. The system is trained using a custom dataset and evaluated through confusion matrix analysis and precision recall metrics to ensure robustness and accuracy. Experimental trials conducted in semi-controlled conditions demonstrate the system’s ability to accurately identify multiple PPE types in real time, offering a reliable and scalable solution for improving safety management in construction environments. KeyWords: Industrial and Construction Safety Automation, AI-Powered PPE Monitoring System, Computer Vision and Deep Learning, Industry 4.0, Real-Time Compliance Analysis,YOLOv8 Object Detection

Concussion-related symptoms, such as impaired balance, slower processing speed, attention deficits, memory dysfunction, and irritability, are thought to result from diffuse axonal injury (DAI), characterized by selective damage to white matter axons. Axons subjected to this mechanical stretch injury exhibit diverse pathological changes, including disruption of axonal transport, neurofilament compaction and degradation, myelin sheath disruption, and loss of sodium channels required for action potential generation and propagation. These distinct forms of axonal pathology may evolve differentially over time and preferentially localize to specific white matter tracts. In this study, we employed the clinically relevant ferret model of concussion using the closed head impact model of engineered rotational acceleration (CHIMERA). 55 male ferrets were randomly allocated to sham or injury groups and then to either 24 h, 72 h, or 14d survival time points. We confirmed that axonal transport disruption and neurofilament pathology represent independent processes, with minimal colocalization but a shared peak of around 72 h following injury. Furthermore, we observed a persistent loss of ankyrin-G, a critical anchoring protein for sodium channels at the node of Ranvier, up to 14d postinjury, suggesting that the resultant impairment in axonal transmission may underlie many concussion symptoms. Indeed, injured ferrets displayed significant deficits in balance, working memory, spatial memory, and recognition memory. These findings demonstrate that the CHIMERA model in ferrets recapitulates key axonal pathologies and their associated clinical manifestations following concussion. This model offers a valuable platform for investigating the temporal evolution of axonal injury and developing targeted therapeutic interventions to mitigate concussion-related deficits.

RE: Impact of daily adaptive head and neck radiotherapy on toxicity and quality-of-life: results of the DARTBOARD phase II randomized trial.

The current study examines head impact exposure in youth soccer and quantifies the relationship between impact location, impact magnitude and brain deformation using data previously collected with an instrumented mouthpiece in combination with a high-resolution brain finite element (FE) model. This study demonstrates that maximum principal strain (MPS) varies by impact source. The largest strains were observed when the ball was kicked prior to the header and the smallest strains were observed resulting from impacts when the headed ball was received from another header.

Throughout time, humans have observed animals performing head impact behaviors in nature and have wondered whether they sustain brain injury. The resulting literature spans centuries and provides both valuable insight and misguided theories. Bighorn sheep and woodpeckers are the two main species studied in this regard and, simultaneously, in current popular culture they are often represented as being immune to brain injury. How did this narrative arise, and is it accurate? This historical review explores these questions by tracing the development of human thought on animal head impacts from prehistoric rock art, through medieval illumination, to the advent of natural history, and finally to modern-day research. As the study of these animals increased, contrasting hypotheses arose regarding both bovids and woodpeckers. While research from engineering and biomedical fields hypothesizes that specialized anatomical features prevent these animals from sustaining brain injury, research from the evolutionary biology field refutes the idea of any such shock-absorption mechanisms. Modern histochemistry techniques have provided cellular evidence of brain injury in both bovids and woodpeckers, and yet biomimicry research continues to seek inspiration for brain protection from these animals. The race for solutions to a growing neurodegeneration epidemic has led to a legacy of unsupported claims amongst the research taking inspiration from head-hitting animals. This review traces the development of these ideas, with a focus on persistent misinformation. By re-examining the literature, it calls for a shift towards evidence-based approaches to more effectively advance our understanding of animal brain injury, and ultimately human health.

PurposeIn recent decades, survival rates for head-and-neck (H&N) cancers have risen, drawing attention to survivors’ working reintegration after treatments. This cohort study aims to evaluate the effect of H&N tumours on the income of employees in the private sector in Italy.MethodsData were extrapolated from the WHIP-Salute archive, which contains work and health information of workers of the private sector in Italy. Incident cases of H&N cancer (between 2004 and 2013) were matched with cancer-free workers using an Optimal Variable Ratio Matching. Linear regression models were used to estimate the effect of H&N tumours on weekly income in the year of diagnosis and in the subsequent two years, overall and stratifying according to sex, job position, and cancer stage.Results592 H&N cancer cases were identified, predominantly male (86%), blue-collar workers (72%), and with localized disease (60%). A significant decline in the average weekly income for workers with cancer compared to their cancer-free counterparts was evident, both in the year of diagnosis (β=-38.59, p < 0.001) and in the next two years (β=-35.60, p < 0.001, and β=-29.95, p < 0.001, respectively). Similar trends were observed in stratified analyses.ConclusionsThis study suggests a short-term disparity in weekly income between workers with H&N cancer and their cancer-free counterparts. Reasons may lie in reduced working capacity of patients following cancer treatments.Implications for cancer survivorsEmployer awareness about survivors’ conditions can enhance workplace inclusivity. Furthermore, the implementation of ad-hoc policies may lead to a successful reintegration of H&N cancer survivors into the workforce.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-025-24801-x.

This study explored the impact of school heads’ instructional leadership on teaching quality and student learning outcomes in the Schools Division of the City of Batac. The role of school heads has expanded beyond administrative functions to include active engagement in instructional leadership, setting clear academic goals, supervising instruction, and supporting teacher development. Guided by the frameworks of the Department of Education’s Results-Based Performance Management System (RPMS) and recent curricular reforms, this research examined how leadership practices influence classroom strategies and learner achievement. Using a descriptive research design, data were gathered from school heads and teachers to assess the extent of leadership practices and their perceived effects on instructional delivery. Findings revealed that effective instructional leadership, characterized by clear vision, consistent monitoring, and responsive professional support affect teaching performance and engagement. However, disparities in classroom outcomes indicated that leadership impact varies depending on the consistency of implementation and contextual factors unique to each school. The results underscored the need for targeted capacity-building programs, strengthened policy support, and context-sensitive interventions to bridge gaps between policy intent and classroom practice. Insights from this study may serve as a basis for enhancing instructional leadership frameworks in similar educational settings across the Philippines.

All cells in the central nervous system (CNS) are considered mechanosensitive, but how they collectively respond to a concussive head impact and contribute to the transition from the primary to secondary injury remains unknown. Using a mouse model for mild traumatic brain injury (mTBI) or concussion, we report that blocking the activity of TRPV4 transient receptor potential channels inhibits mTBI-induced sequential changes of neurons and glial cells, as well as behavioral disturbances. A concussive head impact immediately induces axonal varicosities, preceding NMDA-receptor-mediated microglial activation and cortical demyelination. Afterward, these changes differentially and partially recover. Blocking TRPV4 channels before or after head impact markedly suppresses axon-glial and behavioral changes or enhances their recovery, respectively. Using knockout mice and AAV-Cre-mediated acute and cell-type-specific deletion, we further show that neuronal TRPV4 channels, as an mTBI target, regulate the homeostasis of axon mechanosensation and their hyperactivation causes axonal varicosity formation followed by axon-to-glia mechanotransduction.

Repetitive, sub-concussive head impacts have been associated with increased chronic traumatic encephalopathy (CTE) incidence. CTE diagnosis traditionally relies on postmortem examination, which limits precise correlation between cause and effect. This prospective study embraced innovative diffusion magnetic resonance imaging, which enables in vivo quantification of acute, subacute, and chronic changes in brain tissue microstructure. This approach was used to evaluate changes in white matter microstructural status at intervals up to 180 days following a specified soccer heading protocol. This study was approved by university research ethics committees. Twelve adult males were recruited to the study and gave signed, informed consent. Six Intervention participants were university-level soccer players, with six Control participants drawn from university-level noncontact sports. Multi-shell diffusion-weighted MRI data were acquired on a 3T Siemens Connectom (300 mT/m) scanner using the HARDI protocols. Baseline measures of fractional anisotropy, mean diffusivity, and mean kurtosis were acquired at day 0. The Intervention cohort then performed 10 soccer “headers” in a laboratory, with acceleration-time data captured using an instrumented mouthguard and post-processed to report common metrics. The Intervention group was then re-scanned at day 1 (n = 6), day 90 (n = 5), and day 180 (n = 4). The Control group was re-scanned at day 1 (n = 6) and day 180 (n = 3). Many brain tracts were identified as having significant (p < 0.05) changes in white matter microstructural changes at day 90, which correlated strongly with the magnitude of head impact. A smaller number of tracts had changes at day 1 and day 180. These results indicate that, within this pilot population, the magnitude of repeated soccer headers appears to correlate with the magnitude of white matter microstructural change. Additional investigation is required to determine whether the effect of such an intervention influences long-term brain health risk.Board

This retrospective study used data from the National Alzheimer's Coordinating Center (NACC) database and compared neuropathologic, neuropsychiatric, motor, and neuropsychological features between those with and without chronic traumatic encephalopathy neuropathologic change (CTE-NC). Data were obtained from the NACC database from 2014 to December 2024, with the only inclusion criterion being evaluation for CTE-NC. Participants with CTE-NC were identified and matched approximately 1:4 to those without CTE-NC on demographics (age, education, sex) and staging of Alzheimer and Lewy body neuropathology. Chi-square tests and analyses of covariance (covarying for cognitive symptom duration, time to death, and cognitive diagnosis) compared neuropathologic features, history of traumatic brain injury (TBI), neuropsychiatric symptoms, parkinsonism features, and neuropsychological scores between groups. CTE-NC was present in 0.8% of participants (29/3,845) since 2014. Matching on a 1:4 ratio was achieved for 22 individuals and 1:3 for an additional 3, yielding a total comparison sample of 25 with CTE-NC and 97 without. All but 1 individual with CTE-NC were male with a mean age of 74.7 years (SD = 8.0). Moderate-to-severe Alzheimer neuropathology (54.0%) was common in those with CTE-NC while comorbid cortical or limbic Lewy inclusions were less frequent (8.0%). Compared with those without CTE-NC, those with CTE-NC had higher rates of hippocampal sclerosis (40.0% vs 9.6%; p < 0.001, V = 0.338), progressive supranuclear palsy (16.0% vs 3.1%; p = 0.013, V = 0.224), argyrophilic grain disease (28.0% vs 10,3%; p = 0.023, V = 0.206), other 4R tauopathies (16.7% vs 3.1%; p = 0.011, V = 0.231), other 3R + 4R tauopathies (8.3% vs 1.0%; p = 0.039, V = 0.187), aging-related tau astrogliopathy (33.0% vs 8.9%; p < 0.001, V = 0.313), and transactive response DNA binding protein 43 (TDP-43) inclusions (24.0% vs 7.0%; p = 0.017, V = 0.228). Those with CTE-NC had higher rates of TBI (45.8%) compared with those without CTE-NC (21.9%, p = 0.018, V = 0.217). Neuropsychological scores, neuropsychiatric symptoms, and parkinsonism symptoms did not differ between groups. CTE-NC was rare in NACC since 2014. Those with CTE-NC did not differ in clinical symptoms but had higher rates of hippocampal sclerosis, other tauopathies, and TDP-43 inclusions. In this clinicopathologic investigation using in vivo clinical data, although NACC lacks CTE-NC severity/distribution and repetitive head impact data for sensitivity analyses. Larger in vivo clinicopathologic studies are greatly needed to correlate CTE-NC with clinical features.

Repetitive head impacts (RHI) can lead to lasting brain damage, but not everyone exposed to RHI experiences the same outcomes. In retired fighters, we show that common genetic variants influence whether individuals are more vulnerable or resilient to brain inflammation and injury after repeated trauma. Specifically, APOE4 increased susceptibility, while a MAPT H2 variant appeared protective. These results provide the first in vivo evidence that inherited genetic differences modify long-term brain responses to RHIs. Incorporating genetic risk into studies of brain injury could enable earlier identification of at-risk individuals and support more personalized strategies for monitoring, prevention, and intervention.

Repetitive head impacts (RHI) are blows to the head that do not elicit clinical signs or concussion symptoms. Yet, research suggests that brain integrity and functionality can be altered following a single season of contact collision sports. These deficits are untraceable by current clinical testing. To examine the association between RHI and oculomotor control across a single division I American football season. This single-center cohort study took place from July 2020 to May 2022. Data were analyzed from May 2022 to December 2024. Participants included 25 division I football players (11 high-dose and 14 low-dose; mean age, 20 [SD, 3] years) and 10 controls (mean age, 22 [SD, 1] years). High-dose and low-dose groups were determined by the head impacts incurred during the season using instrumented mouthguards. A single competitive season of contact sports. All football players wore instrumented mouthguards throughout the 2 seasons (2021 to 2022). Each season was treated as an independent observation with no individual football players included in more than 1 season. A random sample of head impacts across the season were video verified. All participants completed an eye tracking task that consisted of following a Landolt-C moving horizontally during fast (90° per second) and slow (30° per second) conditions at preseason (PRE), midseason (MID), and postseason (POST). Smooth pursuit eye movement velocity was calculated and analyzed. A total of 25 male division I American football student-athletes (RHI group; mean age, 20 [SD, 3] years; mean height, 185.72 [SD, 7.40] cm; mean weight, 104.02 [SD, 15.69] kg) and 10 healthy noncontact controls (7 recreationally active [4 female, 3 males] and 3 noncontact National Collegiate Athletic Association swimmers [all female]; mean age, 22 [SD, 1] years) participated in this cohort study. During the season, smooth pursuit eye movement velocity was PRE, 10.01 (SD, 3.16)° per second; MID, 11.48 (SD, 6.57)° per second; and POST, 11.10 (SD, 8.65)° per second for the high-dose group, while the low-dose group was PRE, 11.28 (SD, 4.10)° per second; MID, 11.50 (SD, 5.86)° per second; and POST, 15.02 (SD, 8.26)° per second, with the controls being PRE, 15.60 (SD, 4.44)° per second; MID, 17.95 (SD, 3.73)° per second, and POST, 13.44 (SD, 8.54)° per second. Specifically, at PRE, RHI high-dose players had slower smooth pursuit eye movement velocity compared with controls (difference, 4.28; 95% CI, 2.68-5.81; P = .01). At MID, both high-dose (difference, 8.49; 95% CI, 5.18-11.81; P = .01) and low-dose (difference, 9.15; 95% CI, 6.42-11.87; P = .02) groups had slower smooth pursuit eye movement velocities than controls. In this study, smooth pursuit eye movement velocity was not affected during a single season of contact sports. Group differences suggest existing deficits before the season begins, possibly due to prior contact sport history. Interpretations should be tempered by the small sample size, single institution used for data collection, and the exploratory nature of the study.

Behind the Eyes—Compensation and Complexity in Head Impacts

Rugby Union has attracted increased scrutiny because of concerns over head acceleration events (HAEs), particularly regarding their frequency, severity and potential long-term health implications. While substantial efforts by governing bodies have focused on reducing head impact risks through education, regulatory changes and the introduction of instrumented mouthguards, limited data exist for the community rugby context, especially across different age grades and playing positions. We aimed to quantify HAE across playing positions, age grades and contact phases in community rugby and to identify match scenarios associated with high-magnitude head loading. A prospective observational cohort study included 259 male players across U13, U15, U19, and Premier senior men's grades. Players were fitted with instrumented mouthguards, and match play was video recorded for verification. Head acceleration events were identified from instrumented mouthguard-triggered sensor acceleration events > 5g and coded for match context, player position and contact event characteristics. Statistical models evaluated differences in HAE frequency, incidence rates and head kinematics (peak linear acceleration, peak angular acceleration, rotational velocity change index) across grades, positions and contact scenarios. A total of 7358 HAEs were verified from 8593 sensor acceleration events across 72 matches. Tackles and rucks accounted for ~ 60% of all HAEs. High tackles significantly increased head loading in ball carriers (peak linear acceleration: + 4.16g, p = 0.02; peak angular acceleration: + 443rad/s2, p = 0.002; rotational velocity change index: + 1.87rad/s, p = 0.04), while low tackles elevated head loading in tacklers (peak linear acceleration: + 4.9g, p = 0.004). Upright tacklers were more likely to produce high tackles (p < 0.001) and head-to-head contacts (p = 0.019). U13 ball carriers showed higher rotational loading than tacklers (rotational velocity change index: + 5.01rad/s, p = 0.008), likely reflecting frequent secondary mechanisms such as head-to-ground and body-to-ground. Defensive rucks carried a greater HAE risk than attacking rucks (all p < 0.05), particularly for U19 jacklers (incidence rate ratio = 2.27, p < 0.0001). Tackles and rucks are primary sources of HAEs, with risk shaped by posture, tackle height and player role. Lower tackle heights reduce ball carrier load but increase tackler exposure, indicating a potential safety trade-off. Younger players, particularly U13s, were more susceptible to secondary impacts (e.g. head-to-ground), potentially because of limited task-specific experience and underdeveloped control during the tackled phase. Position- and age-specific strategies may be required to optimise safety and reduce HAE risk across all levels of community rugby.

Repetitive head impacts are associated with structural brain changes and an increased risk for chronic traumatic encephalopathy, a progressive neurodegenerative disease that can only be diagnosed after death. Chronic traumatic encephalopathy is defined by the abnormal accumulation of phosphorylated tau protein, particularly at the depths of the superior frontal sulci, suggesting that sulcal morphology may serve as a relevant structural biomarker. Contact sport athletes, such as former football players, are at elevated risk due to their prolonged exposure to repetitive head impacts. Cortical atrophy linked to underlying tau accumulation may result in shallower and wider sulci, potentially making sulcal morphology an imaging marker for identifying individuals at risk for this disease. This study investigated sulcal morphological differences in former football players and examined associations with age, football-related exposure, clinical diagnosis of traumatic encephalopathy syndrome, levels of certainty for chronic traumatic encephalopathy pathology, neuropsychological performance, and positron emission tomography imaging using flortaucipir. We analysed structural magnetic resonance imaging data from 169 male former football players (mean age 57.2 (8.2) years, range 45–74) and 54 age-matched, unexposed asymptomatic male controls (mean age 59.4 (8.5) years, range 45–74). Sulcal depth and width were quantified using the CalcSulc, focusing on two regions in each hemisphere commonly affected by chronic traumatic encephalopathy pathology: the superior frontal and occipitotemporal sulci. Generalized least squares models were used to assess group differences and interactions with age and football exposure variables, including age of first exposure, total years played, and cumulative head impact exposure. An analysis of covariance evaluated relationships between sulcal morphology, clinical measures, and flortaucipir uptake, adjusting for age, race, body mass index, education, imaging site, apolipoprotein E4 status, and total intracranial volume. Former football players demonstrated significantly shallower sulcal depth in the left superior frontal sulcus compared to unexposed controls. Earlier age of first exposure and longer football careers were associated with greater widening of the left occipitotemporal sulcus. Higher cumulative head impact exposure was linked to reduced sulcal depth in the left superior frontal region. However, sulcal morphology was not associated with clinical diagnosis, levels of certainty, neuropsychological test performance, or flortaucipir imaging. These findings suggest that sulcal morphology may reflect cumulative exposure to repetitive head impacts, particularly in brain regions vulnerable to chronic traumatic encephalopathy pathology. Future ante- and post-mortem validation studies are needed to determine whether sulcal morphology can serve as a reliable in vivo biomarker of risk.

Law enforcement cadets (LECs) complete occupational combat training that exposes them to head acceleration events (HAEs) at variable magnitudes and quantities. Previous sport-related HAE studies suggest that neck strength is a potential modifiable factor to reduce HAE exposure risk, but the effect differs across scenarios and populations. The purpose of this study was to examine the effect of baseline neck strength on HAE exposure for LECs during training. This was a prospective, observational study where we measured LEC's isometric neck strength using a handheld dynamometer and recorded HAEs >5 g using instrumented mouthguards in 28 civilian LECs (9 females, 28 ± 8 years). A principal component analysis (PCA) followed by an adjusted linear regression model was used to test the hypothesis that LECs with greater neck strength and larger neck girth would sustain HAEs of lower quantity and magnitude. Male LECs were taller, weighed more, had greater neck strength, and had larger neck girths than female LECs. PCA demonstrated no significant effect of neck characteristics on HAEs per athlete exposure, median peak linear acceleration, or median peak rotational velocity when controlling for sex. Secondary analyses confirmed measures of neck strength were not associated with HAE quantity or magnitude. Neck girth was not associated with HAE magnitude; however, greater neck girth was associated with greater HAE exposure. Findings suggest that neck strength may not be an important target for future HAE exposure risk reduction efforts. Future work should aim to identify other risk or protective factors (e.g., prior sport participation and military history) to decrease repetitive head impact exposure, and generally promote the health and well-being of LECs during their participation in mandatory training.

The current safety standard, 44 mm maximum backface deformation, for high-rate non-penetrating blunt impacts (NPBIs) is based on preliminary data and does not account for differences in injury risk for different organs. Therefore, further studies are needed to develop a more robust understanding of the injury mechanism of NPBI and injury risk. Live animal testing allows for the quantification of injury outcomes from insult to injury; however, it is limited by instrumentation, time, and cost. Finite element modeling can overcome these limitations and assist in the interpretation of experimental results. This study sought to validate a finite element ovine thorax model (FE-OTM) against experimental data for high-rate NPBIs. The experimental testing consisted of 20 impacts with initial velocities of about 40 m/s, maximum impact depths from 20 to 60 mm, impact angles of 0 to 25 degrees from the spine normal in the caudal direction, and 2 different impactor head shapes. Each experimental test measured impactor displacement through high-speed video and axial strain on the impactor's shaft. Further analysis was used to determine the peak force, transferred energy, and imparted impulse. A subject-specific validation matrix was run on the FE-OTM v2.0 in which the model was scaled to match the gross dimensions of each experimental test, the impactor was aligned to match the impact angle, and the impactor's motion was defined based on the experimental displacement versus time trace. The peak force, transferred energy, and imparted impulse were compared between the FE-OTM and experiments using cross-correlation and linear regression. The results found slopes of 1.03, 1.74, and 1.97 and R2 values of 0.92, 0.94, and 0.95 for force, energy, and impulse, respectively. The high R2 values indicated that the model has a strong linear relationship with the experimental results. Therefore, the model has been validated for high-rate NPBI impacts. Future work will use this model to develop organ specific strain-based injury metrics for high-rate NPBIs and expand model application to other environments.

A french version of the OSU TBI-ID for screening TBI in PTSD Military personnel.

The utility of adaptive radiotherapy (ART) for head and neck squamous cell carcinoma (HNSCC) remains poorly defined. Daily ART (DART) promises both anatomic adaptation and planning target volume (PTV) reduction. In this prospective trial using cone-beam computed tomography-based ART, patients with HNSCC undergoing definitive radiotherapy (RT) or chemoradiotherapy (CRT) were randomized to DART with reduced PTV margins or no ART with standard margins (image-guided RT [IGRT]). Eligibility criteria included a diagnosis of oropharynx, larynx, or hypopharynx HNSCC receiving definitive radiotherapy. All individuals received involved nodal radiotherapy per previous institutional study. The PTV margins were 1 mm (2 mm craniocaudal) versus 5 mm in the DART and IGRT arms, respectively. The primary endpoint was patient-reported xerostomia at one year, assessed with the Xerostomia Questionnaire (XQ). Fifty patients were enrolled (26 IGRT, 24 DART) between March 2022 and June 2023. The cohort consisted of 38 oropharynx and 12 larynx/hypopharynx patients. The mean ipsilateral parotid gland, ipsilateral and contralateral submandibular gland doses were significantly lower with DART. There was significantly less acute dermatitis in the DART arm (Grade 0/1/2 0%/69%/31% vs. 17%/75%/8% DART, p = 0.01) but no significant difference in any patient-reported outcome at one year. The adjusted difference in XQ score at one year was 10.0 (95% CI -4.7-24.7, p = 0.58). Online DART for HNSCC is oncologically sound and improved acute toxicity profiles, but it did not reduce patient-reported xerostomia, the primary endpoint. Additional evidence is needed to understand the potential benefits and limitations of this paradigm, including its cost-effectiveness. Clinicaltrials.gov identifier, NCT04883281.