Factors influencing the injury severity score and the probability of survival in patients who fell from height

In Japan, falls from height result in the second highest trauma mortality rate after traffic motor vehicle collisions and the highest trauma-related mortality rate amongst young people. We aimed to identify factors that worsen injury severity and lower survival probability of patients who fell from height and to contribute to the improvement of their prehospital and in-hospital care. This retrospective analysis retrieved hospital records of 179 patients aged ≥ 15 years who were transported to our hospital after a fall from height during April 2014–March 2020. On multiple regression analysis, fall height ≥ 5 m more significantly resulted in higher the injury severity score. Logistic regression analysis revealed that fall height ≥ 5 m with the reference of 2–3 m significantly resulted in lower the survival probability with odds ratio (95% confidence interval) of 0.10 (0.02–0.55). Using ‘feet-first’ as the reference body position, the odds ratios (95% confidence interval) of survival for those who impacted the surface on the lateral or dorsal regions were 0.11 (0.02–0.64) and 0.17 (0.03–0.99), respectively. Collecting information on the abovementioned factors at pre-hospitalisation may facilitate prompt diagnosis and treatment. These results may help improve prehospital and in-hospital care, avoiding preventable trauma deaths.

The Value of Interleukin-6 among Several Inflammatory Markers as a Predictor of Respiratory Failure in COVID-19 Patients

Patients with coronavirus disease 2019 (COVID-19) develop severe respiratory failure within a short period during the clinical course. It is essential to predict respiratory deterioration in the short term. We investigated the use of inflammatory markers to predict respiratory distress within three days from their analysis in COVID-19 patients. This retrospective observational study included 81 patients admitted with COVID-19. Patients were divided into two groups according to whether the maximum fraction of inspired oxygen (FiO₂) for three days from the blood marker measurements was ≥0.4 (high FiO₂ group; HFG) or <0.4 (low FiO₂ group; LFG). Interleukin-6 (IL-6), C-reactive protein (CRP), lactate dehydrogenase (LDH), white blood cell, D-dimer, and creatinine levels were compared between the two groups. The levels of all markers were significantly higher in HFG patients. Areas under the receiver operating characteristic curve of IL-6, CRP, and LDH had high values of 0.85, 0.82, and 0.81, respectively. The odds ratio of IL-6 which was crude and adjusted for dexamethasone administration initiated before laboratory measurement, showed the high value of 29.1 (5.6-295.6) and 53.9 (4.5-3242.8), respectively. IL-6 can be used as a reliable marker for predicting respiratory illness within three days after assessment.

Tightening legal restrictions for drivers with epilepsy in Japan

Epilepsy is a highly prevalent condition around the world, and many countries impose restrictions on drivers with epilepsy. After toughening the law in Japan, the number of refused driving license applications for patients with epilepsy increased markedly. However, the number of collisions caused by drivers with epilepsy did not decrease.

Factors influencing the length of emergency room stay and hospital stay in non-fatal bicycle accidents: A retrospective analysis

PURPOSE

Lengthy hospitalization places a burden on patients and healthcare resources. However, the factors affecting the length of hospital stay (LHoS) and length of emergency room stay (LERS) in non-fatal bicycle accidents are currently unclear. We investigated these factors to inform efforts to minimize hospitalization.

METHODS

We performed a retrospective analysis of data from non-fatal injured bicyclists admitted to the Emergency and Critical Care Center at Kyoto Medical Center between January 2012 and December 2016. We measured LHoS, LERS, mechanism of injury, head injury prevalence, polytrauma, operations performed, injury severity score (ISS), abbreviated injury scale (AIS) score, maximum AIS score, and trauma and injury severity score probability of survival. We conducted multiple regression analysis to determine predictors of LHoS and LERS.

RESULTS

Within the study period, 82 victims met the inclusion and exclusion criteria and were included. Mean age was (46.0 ± 24.7) years. Overall mean LHoS was (16.8 ± 25.2) days, mean LERS was (10.6 ± 14.7) days, median ISS was 9 (interquartile range (IQR): 3-16), median maximum AIS was 3 (IQR: 1-4), and median trauma and injury severity score probability of survival was 98.0% (IQR: 95.5%-99.6%). Age, maximum AIS, ISS, and prevalence of surgery were significantly greater in long LHoS and LERS group compared with short LHoS and LERS group (p < 0.05). Performance of surgery independently explained LHoS (p = 0.0003) and ISS independently explained LERS (p = 0.0009).

CONCLUSION

Surgery was associated with long hospital stays and ISS was associated with long emergency room stays. To improve the quality life of the bicyclists, preventive measures for reducing injury severity or avoiding injuries needing operation are required.

Visual texture agnosia caused by bilateral posterior cerebral artery stroke: a case study

A 57-year-old man presented with a bilateral posterior cerebral artery attack and was visually impaired. He had a hard time identifying familiar faces and shades. He also felt that the familiar building looked different, and complained that it was not possible to tell from visual information alone whether the food was cooked or the kimono fabric was soft.We assessed the patient's visual function using real materials and material images and was diagnosed with visual texture agnosia. There are few reports of visual texture agnosia, detailed evaluation is considered important because perceiving texture is important for activities of daily living.

Factors Influencing Pregnant Women's Injuries and Fetal Loss Due to Motor Vehicle Collisions: A National Crash Data-Based Study

To examine the factors that influence substantial injuries for pregnant women and negative fetal outcomes in motor vehicle collisions (MVCs), a retrospective analysis using the National Automotive Sampling System/Crashworthiness Data System was performed in Shiga University of Medical Science. We analyzed data from 736 pregnant women who, between 2001 and 2015, had injuries that were an abbreviated injury scale (AIS) score of one or more. The mean age was 25.9 ± 6.4 years and the mean gestational age was 26.2 ± 8.2 weeks. Additionally, 568 pregnant women had mild injuries and 168 had moderate to severe injuries. Logistic regression analysis revealed that seatbelt use (odds ratio (OR), 0.30), airbag deployment (OR, 2.00), and changes in velocity (21–40 km/h: OR, 3.03; 41–60 km/h: OR, 13.47; ≥61 km/h: OR, 44.56) were identified as independent predictors of having a moderate to severe injury. The positive and negative outcome groups included 231 and 12 pregnant women, respectively. Injury severity in pregnant women was identified as an independent predictor of a negative outcome (OR, 2.79). Avoiding moderate to severe maternal injuries is a high priority for saving the fetus, and education on appropriate seatbelt use and limiting vehicle speed for pregnant women is required.

Hit-and-runs more common with pedestrians lying on the road: Analysis of a nationwide database in Japan

PURPOSE

To determine the trends with fatally or otherwise injured pedestrians lying on the road and the relationship to hit-and-run incidents in Japan.

METHODS

We extracted data for 2012-2016 from the records of the Institute for Traffic Accident Research and Data Analysis, Japan, a nationwide traffic accident database. All the injured and fatally injured pedestrians were selected. We examined the levels of pedestrian injury, vehicle speed immediately before the collision, whether or not the pedestrian was lying on the road, and hit-and-run incidents. Chi-square test was employed to make a statistical comparison between the two groups.

RESULTS

The database contained data on 286,383 pedestrian casualties and 7256 fatalities; 8.3% of fatalities (602 persons) and 0.6% of casualties (1827 persons) involved pedestrians lying on the road. The rates of fatalities and severe injuries were significantly higher for pedestrians who were lying on the road than for those who were not. Hit-and-run incidents were evident in 4.0% of casualties and 7.3% of fatalities. The rate of hit-and-run cases was also significantly higher among pedestrians who were lying on the road. Among fatally injured pedestrians not lying on the road, the rates with speeds of ≥30 km/h did not differ significantly between hit-and-run and other cases. However, when the pedestrians were lying on the road, the rate was significantly increased in hit-and-run cases.

CONCLUSION

This is the first report to focus on pedestrians lying on the road and being involved in hit-and-run incidents. In addition to preventing hit-and-run incidents, prevention of pedestrians lying on the road could also decrease fatalities.

Complement C9 expression is associated with damaged myocardial cells in pediatric sudden death cases of fulminant myocarditis

Background

Because disease progression is so fast in sudden death of acute fulminant myocarditis, damage of myocardial cells is not evident in routine hematoxylin and eosin staining. To understand damage to myocardial cells and the mechanism of sudden death, immunohistochemical staining was performed for two forensic autopsy cases.

Case presentation

The patients were a healthy 5-year-old girl and 8-year-old boy. They suddenly died within 2 days of appearance of flu-like symptoms. An autopsy showed accumulation of yellowish-clear pericardial fluid containing fibrin deposits, fluid blood in the heart, and congestion of visceral organs. Histologically, minor necrosis or degeneration of myocardial cells with mainly lymphocytic infiltration was observed sometimes in tissue sections. Immunohistochemically, positive complement C9 staining and negative sirtuin 1 staining were found. These findings suggested wide damage of myocardial cells, even in regions with no marked changes in myocardial cells with hematoxylin and eosin staining. These areas corresponded to those with strong accumulation of lymphocytes.

Conclusions

Immunohistochemistry for complement C9 and sirtuin 1 might become a new tool for evaluating damage of myocardial cells of fulminant acute myocarditis.

Maxillofacial Injuries in Cyclists: A Biomechanical Approach for the Analysis of Mechanisms of Mandible Fractures

PURPOSE

The investigators characterized the occurrence of maxillofacial injuries in cyclists and biomechanically analyzed the mechanisms of mandible fractures.

METHODS

We retrospectively analyzed injury data and performed biomechanical analyses with finite element models. Hospital records from 2011 through 2019 were reviewed to identify patients who had sustained oral and maxillofacial injuries while riding a bicycle. Patients with maxillofacial fractures were compared to those without. Logistic regression analysis was performed to identify which variables were independently associated with the occurrence of maxillofacial fractures. To reconstruct the injury scenario (one in which a person falls from a bicycle and contacts the road surface with their face), computer simulations using The Total Human Model for Safety model were performed.

RESULTS

The hospital records of 94 patients (62 men, 32 women; 26.1 ± 17.3 years of age) who sustained oral and maxillofacial injuries while riding a bicycle were reviewed. Twenty patients (21.3%) sustained maxillofacial fractures; mandible fractures were most common (16 patients). Patients with maxillofacial fractures were significantly older and had higher severity injuries; however, logistic regression analysis showed that only age was an independent predictor of the occurrence of maxillofacial fracture (odds ratio, 1.03; P = .025). In simulations, higher von Mises stresses were found in the mandible when the cyclist fell with the neck extended and the body horizontal, and consequently, the center of mandibular body strikes the road surface. Contact forces were approximately 8 kN. High tensile stresses occurred laterally and high compressive stresses occurred medially in the mandibular ramus, which indicated that the mandibular ramus deformed in the transverse plane.

CONCLUSION

Biomechanical analyses show that mandible fractures can occur when a cyclist falls from a bicycle and their lower face strikes the road's surface.

Factors influencing the long-term hospitalization of bicyclists and motorcyclists with oral and maxillofacial injuries

BACKGROUND/AIM

Because bicyclists and motorcyclists with oral and maxillofacial injuries often suffer from disabilities requiring long-term treatment, reducing the severity of such injuries is a valuable objective for improving these people's quality of life (QOL). The aims of this study were, first, to present the prevalence and patterns of oral and maxillofacial injuries of bicyclists and motorcyclists and to compare the features of these injuries and, second, to determine the factors contributing to long-term hospitalization for these patients and to propose effective preventive measures.

MATERIAL AND METHODS

This was a single-center retrospective analysis. Hospital records from 2011 through 2018 were reviewed for all patients who had sustained oral and maxillofacial injuries in bicycle or motorcycle collisions and had presented at a university hospital which was the only hospital in the region attended 24 hours per day by oral and maxillofacial surgeons. Characteristics of the oral and maxillofacial injuries, injury severity, and factors influencing the length of hospitalization were examined.

RESULTS

Records of 130 patients (82 bicyclists and 48 motorcyclists) with a mean age of 28.0 years were analyzed. Thirty-three patients (25.4%) had maxillofacial fractures, with 41 fracture lines while 103 patients (79.2%) had dental injuries and 57 patients (43.8%) had soft-tissue injuries. The distribution and prevalence of oral and maxillofacial injuries were similar for bicyclists and motorcyclists. However, motorcyclists had significantly higher Abbreviated Injury Scale (AIS) scores for facial injuries and the maximum AIS score than did bicyclists. According to a multiple regression analysis, the number of fracture lines and the requirement for intermaxillary fixation were independent factors influencing long-term hospitalization (standard regression coefficients: 6.795 and 6.715, respectively; P < .001).

CONCLUSIONS

The number of fracture lines and the use of intermaxillary fixation were independent factors influencing long-term hospitalization of both bicyclists and motorcyclists with oral and maxillofacial injuries.

Factors Influencing Gait Velocity Improvement Following Botulinum Toxin Injection for Spasticity of the Plantar Flexors in Patients with Stroke

Objective:

In patients with hemiplegia, botulinum toxin type A injection for ankle spasticity of the plantar flexors reportedly improves walking speed. This improvement may be affected by background factors and patient baseline physical performance. This study aimed to clarify the factors affecting gait velocity improvement after botulinum toxin type A injection.

Methods:

Background and evaluation data were collected for 60 patients with stroke who received botulinum toxin type A injection for spasticity of the plantar flexors. The patients were divided into improvement (n=27) and non-improvement (n=33) groups based on the gait velocity change from before injection to 2 weeks after injection. Logistic regression analysis was performed with the improvement and non-improvement groups as response variables and background data and evaluation data at baseline as explanatory variables.

Results:

The presence or absence of physical therapy following botulinum toxin type A injection (odds ratio: 7.82) was the only significant explanatory variable for gait velocity change.

Conclusion:

Background factors and physical performance at baseline did not affect gait velocity improvement after botulinum toxin type A injection. If botulinum treatment of the ankle plantar flexors in patients with stroke is targeted at walking performance improvement, then physical therapy following botulinum toxin type A injection should be an essential part of the treatment strategy.

Both Autopsy and Computed Tomography Are Necessary for Accurately Detecting Rib Fractures Due to Cardiopulmonary Resuscitation

Few studies have compared the sensitivities of autopsy and post mortem computed tomography (PMCT) in detecting rib fractures caused by cardiopulmonary resuscitation (CPR). We aimed to compare the characteristics between both modalities for accurately detecting CPR-related rib fractures. This single-centre observational study included adult patients with autopsy records and PMCT scans at our institution from January 2013 to March 2019. CPR-related rib fractures were evaluated using autopsy and PMCT findings. In 62 patients enrolled, 339 rib fractures were detected on autopsy and/or PMCT (222 fractures on both PMCT and autopsy, 69 on PMCT alone, and 50 on autopsy alone). The agreement of detection for both modalities was substantial (kappa coefficient, 0.78). In the logistic regression model, incomplete fractures detected by PMCT and age <75 years were significantly associated with findings that were negative on autopsy but positive on PMCT, while rib number (ribs 1–3 and 7–12) and fracture location (posterolateral and paravertebral) were significantly associated with negative PMCT findings but positive autopsy findings. Autopsy and PMCT showed complementary roles, and are thus necessary in accurately detecting CPR-related rib fractures. Combining both modalities may contribute to improved CPR quality and better understanding of discrepancy in characteristics between the two modalities.

Pedaling improves gait ability of hemiparetic patients with stiff-knee gait: fall prevention during gait

BACKGROUND AND PURPOSE

Stiff-knee gait, which is a gait abnormality observed after stroke, is characterized by decreased knee flexion angles during the swing phase, and it contributes to a decline in gait ability. This study aimed to identify the immediate effects of pedaling exercises on stiff-knee gait from a kinesiophysiological perspective.

METHODS

Twenty-one patients with chronic post-stroke hemiparesis and stiff-knee gait were randomly assigned to a pedaling group and a walking group. An ergometer was set at a load of 5 Nm and rotation speed of 40 rpm, and gait was performed at a comfortable speed; both the groups performed the intervention for 10 min. Kinematic and electromyographical data while walking on flat surfaces were immediately measured before and after the intervention.

RESULTS

In the pedaling group, activity of the rectus femoris significantly decreased from the pre-swing phase to the early swing phase during gait after the intervention. Flexion angles and flexion angular velocities of the knee and hip joints significantly increased during the same period. The pedaling group showed increased step length on the paralyzed side and gait velocity.

CONCLUSIONS

Pedaling increases knee flexion during the swing phase in hemiparetic patients with stiff-knee gait and improves gait ability.

Factors Associated with Poor Outcomes in Patients with Mild or Moderate Acute Subdural Hematomas

The factors influencing the outcomes of mild/moderate acute subdural hematoma (ASDH) are still unclear. Retrospective analyses were performed to identify such factors. The medical records of all patients who were admitted to Saiseikai Shiga Hospital with mild (Glasgow Coma Scale [GCS] score of 14–15) or moderate (GCS score of 9–13) ASDH between April 2008 and March 2017 were reviewed. Comparisons between the patients who exhibited favorable and poor outcomes were performed. Then, independent factors that contributed to poor outcomes were identified via logistic regression analyses. A total of 266 patients with a mean age of 70.2 were included in this study. The most common concomitant injuries were subarachnoid hemorrhages (SAHs; 56.8%). The patients’ Injury Severity Scores (ISS) ranged from 16 to 75 (median: 21). The 66 moderate ASDH patients exhibited significantly higher frequencies of surgery and mortality (24.2% and 13.6%, respectively) than the 200 mild ASDH patients (8.0% and 4.5%, respectively). The factors associated with poor outcomes were age (odds ratio [OR]: 1.06) and the ISS (OR: 1.24) in the mild ASDH patients, and older age (OR: 1.09) and the higher ISS (OR: 1.15) in the moderate group, too.

Cerebral oxygenation monitoring during resuscitation by emergency medical technicians: a prospective multicenter observational study

Aim

To assess the feasibility and predictive ability of regional cerebral oxygen saturation monitoring during cardiopulmonary resuscitation by emergency medical technicians.

Methods

This prospective observational study included 33 cardiac arrest patients who received cardiopulmonary resuscitation in a prehospital setting. Patients were connected to a near‐infrared spectrometer through two disposable probes immediately after entering the ambulance. The monitor, which showed regional cerebral oxygen saturation readings, was obscured by covering it with a sheet of paper. Regional cerebral oxygen saturation was measured continuously until hospital arrival. Outcome variables included the prehospital return of spontaneous circulation, survival to hospital admission, and survival at 90 days.

Results

For patients who survived >90 days after hospital admission (n = 2), the mean regional cerebral oxygen saturation values upon ambulance and hospital arrival were 24% and 60%, respectively; for patients who did not survive (n = 31), the mean regional cerebral oxygen saturation values were 15% and 17%, respectively. Regional cerebral oxygen saturation values increased to a greater extent between ambulance arrival and hospital arrival in patients who survived >90 days (median, 36%; interquartile range, 32–40%) than in those who did not survive (0; 0–6%; P = 0.07). Additionally, regional cerebral oxygen saturation values were not related to the prehospital return of spontaneous circulation or survival to hospital admission.

Conclusion

Regional cerebral oxygen saturation could be monitored during resuscitation by emergency medical technicians, and it can be used during physiological monitor‐guided cardiopulmonary resuscitation.

Ukemi Technique Prevents the Elevation of Head Acceleration of a Person Thrown by the Judo Technique 'Osoto-gari'

Biomechanical analysis was performed to evaluate the effectiveness of mastering ukemi in preventing severe head injury in judo. One judo expert (tori) threw another judo expert (uke) with a skilled break-fall (ukemi) four times. We obtained kinematic data of uke with a digital video camera. Both translational and rotational accelerations were measured with a six-degree-of-freedom sensor affixed to uke’s forehead. When Osoto-gari was performed, uke fell backward and his arm made contact with the tatami; the translational and rotational accelerations rose to peak values. The peak resultant translational and rotational accelerations were respectively 10.3 ± 1.6 G and 679.4 ± 173.6 rad/s² (mean ± standard deviation). Furthermore, when comparing the values obtained for the judo experts with those obtained using an anthropomorphic test device (ATD: the POLAR dummy) that did not perform ukemi, both the peak resultant translational (P = 0.021) and rotational (P = 0.021) accelerations of uke were significantly lower than those for the ATD, whose head struck the tatami. Additionally, there was no significant difference among the three axis directions for either translational (a_x: 7.4 ± 0.2, a_y: 8.5 ± 2.1, a_z: 7.2 ± 0.8 G) or rotational (α_x: 576.7 ± 132.7, α_y: 401.0 ± 101.6, α_z: 487.8 ± 66.6 rad/s²) acceleration. We confirmed that performing correct ukemi prevented the elevation of head acceleration by avoiding head contact with the tatami when a judoka is thrown by Osoto-gari. Judoka should therefore undertake intensive practice after they have acquired ukemi skills.

Forensic Autopsies can Determine Latent Prostate Cancer Prevalence

To evaluate the usefulness of forensic autopsies in determining latent prostate cancer (PC) prevalence, we examined latent PC prevalence from autopsies and compared our findings between decedents with and without cancer. Data from forensic autopsies performed in Japan from 2004 to 2014 were obtained. For each prostate, histopathological examinations were performed in both the base and the apex sections. Three hundred and seventeen Japanese decedents were selected for analysis. The mean age of decedents was 56.4 ± 17.8 years (range, 14-94 years). Among this population, 39.4% died suddenly of disease and 60.6% died of external causes. Latent PC was identified in 45 (14.2%) decedents, who ranged from 27 to 93 years old (mean, 71.1 ± 12.9 years). The prevalence of clinically significant PC with a Gleason score of 7 or more was 8.8%, and the rate increased with age. Fifteen males had cancers other than PC. The prevalence of overall latent PC was significantly higher for those with cancer compared with those without (40.0% vs. 12.9%; P = 0.003). In this study, the use of forensic autopsy materials provided the opportunity to obtain a more accurate natural history of PC, as the decedents in this situation would have been more likely to have died suddenly while behaving as normal prior to death, and less likely to have been impacted by long-term medical interventions.

Identification of transmembrane protein 168 mutation in familial Brugada syndrome

Brugada syndrome (BrS) is an inherited channelopathy responsible for almost 20% of sudden cardiac deaths in patients with nonstructural cardiac diseases. Approximately 70% of BrS patients, the causative gene mutation(s) remains unknown. In this study, we used whole exome sequencing to investigate candidate mutations in a family clinically diagnosed with BrS. A heterozygous 1616G>A substitution (R539Q mutation) was identified in the transmembrane protein 168 (TMEM168) gene of symptomatic individuals. Similar to endogenous TMEM168, both TMEM168 wild-type (WT) and mutant proteins that were ectopically induced in HL-1 cells showed nuclear membrane localization. A significant decrease in Na⁺ current and Na_v 1.5 protein expression was observed in HL-1 cardiomyocytes expressing mutant TMEM168. Ventricular tachyarrhythmias and conduction disorders were induced in the heterozygous Tmem168 1616G>A knock-in mice by pharmacological stimulation, but not in WT mice. Na⁺ current was reduced in ventricular cardiomyocytes isolated from the Tmem168 knock-in heart, and Na_v 1.5 expression was also impaired. This impairment was dependent on increased Nedd4-2 binding to Na_v 1.5 and subsequent ubiquitination. Collectively, our results show an association between the TMEM168 1616G>A mutation and arrhythmogenesis in a family with BrS.

Differences in severity of injuries between motorcyclist and bicyclist fatalities in single vehicle collisions

To understand the injury severity of bicyclists and motorcyclists in single vehicle collisions, we performed a retrospective analysis of forensic autopsy cases of 25 motorcyclists and 14 bicyclists performed from 1999 to 2018. Collision details, injury characteristics, and involvement of alcohol were examined. The injury severity between bicyclists and motorcyclists was compared. The average age of victims was 62.3 years. All motorcyclists and no bicyclists wore a helmet. Motorcyclists had more severe injuries than bicyclists (mean Injury Severity Score of 42 and 27, respectively). The motorcyclists had more severe chest injuries but fewer severe facial injuries than bicyclists, owing to the difference in collision velocity or rate of helmet use (p < 0.05). Alcohol was present in the blood of 52.0% of bicyclists but no motorcyclists. The mean blood alcohol concentration of these bicyclists was 1.59 mg/mL. The bicyclists under the influence of alcohol had more severe injuries to neck and upper extremities than non-drunken bicyclists (p < 0.05). Our results may be useful for determining the cause of death and reconstructing the mechanisms of fatal injuries in bicyclists and motorcyclists.

Biomechanical Analysis of the Head Movements of a Person Thrown by the Judo Technique 'Seoi-nage'

The present study examined the kinematics and biomechanical parameters of the head of a person thrown forward by the judo technique ‘Seoi-nage’. A judo expert threw an anthropomorphic test device (the POLAR dummy) five times. Kinematics data were obtained with a high-speed digital video camera. Linear and angular accelerations of the head were measured by accelerometers mounted at the center of gravity of the dummy’s head. When Seoi-nage was performed, the dummy fell forward accompanied by contacting the anterior parietal regions of the head to the tatami, and the linear and angular accelerations of most axes reached peak values when the head contacted the tatami. Peak resultant linear and angular accelerations were 20.3 ± 9.8 G and 1890.1 ± 1151.9 rad/s², respectively (means ± standard deviation). Peak values in linear and angular acceleration did not significantly differ between the three directional axes. Absolute angular accelerations in all axes observed in Seoi-nage were high and the resultant value was approximately equal to the already reported in Ouchi-gari, one of the predominant techniques causing judo-related acute subdural hematoma. However, the remarkable increase of linear acceleration in the longitudinal direction and/or angular acceleration in the sagittal plane, as previously reported in techniques being thrown backward (i.e., Ouchi-gari and Osoto-gari), was not detected. The likely mechanism of acute subdural hematoma caused by Seoi-nage is that a large angular acceleration causes large strains and deformations of the brain surface and subsequent rupture of cortical vessels.