Jason Forman

Jason Forman
University of Virginia | UVa · Department of Mechanical and Aerospace Engineering

PhD

About

141
Publications
21,507
Reads
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1,427
Citations
Additional affiliations
January 2012 - present
University of Virginia
Position
  • Principal Investigator
January 2010 - December 2011
Universidad de Navarra
Position
  • Professor (Associate)

Publications

Publications (141)
Article
Full-text available
Understanding the risk of skin injury caused by impacts from blunt less lethal weapons (LLW) is critical for designing safer devices, but the tolerances of injury are still understudied. Previous research has utilized post-mortem human surrogates (PMHS) to investigate the injury thresholds of various soft tissues; however, PMHS testing is often lim...
Article
Full-text available
Less-lethal weapons (LLWs) based on blunt impactors are seeing increased usage during crowd-control scenarios, and it is crucial that these devices do not inflict significant injuries when used. The guidelines for safe impactor design can be informed by rigorous biomechanical testing and injury risk analysis. In this study, high-rate blunt impact t...
Article
Vehicle safety systems have substantially decreased motor vehicle crash-related injuries and fatalities, but injuries to the lumbar spine still have been reported. Experimental and computational analyses of upright and, particularly, reclined occupants in frontal crashes have shown that the lumbar spine can be subjected to simultaneous and out-of-p...
Article
Purpose: Finite element (FE) modeling has been used as a research tool for investigating underlying ligaments biomechanics and orthopedic applications. However, FE models of the ligament in the foot have been developed with various configurations, mainly due to their complex 3D geometry, material properties, and boundary conditions. Therefore, the...
Article
Full-text available
Morphing can be used to alter human body models (HBMs) to represent a diverse population of occupants in car crashes. The mid-sized male SAFER HBM v9 was parametrically morphed to match 22 Post Mortem Human Subjects, loaded in different configurations. Kinetics and kinematics were compared for the morphed and baseline HBMs. In frontal impacts, the...
Article
Objective: This short communication presents an approach as an objective means to validate that population variability is potentially incorporated into human body models in an accurate way, complementing existing validation techniques based on individual experiment-simulation comparison. This shall provide a further option for the assessment of th...
Conference Paper
Full-text available
Pelvis fractures between the anterior superior iliac spine (ASIS) and anterior inferior iliac spine (AIIS) have been observed in frontal-crash sled tests over the last 50 years. This paper presents the methods used and results obtained from a new study aimed to replicate lap belt loading conditions from sled tests in a more controlled, isolated, be...
Conference Paper
Full-text available
Child booster seats vary in size, shape and material, and the effects of these parameters on occupant response are not well understood. Large-scale computational studies are a means to explore the effects of these parameters across the space of potential booster designs. This work lays the foundation for such large-scale studies by quantifying the...
Article
Full-text available
As one of the most frequently occurring injuries, thoracic trauma is a significant public health burden occurring in road traffic crashes, sports accidents, and military events. The biomechanics of the human thorax under impact loading can be investigated by computational finite element (FE) models, which are capable of predicting complex thoracic...
Preprint
Full-text available
Vehicle safety systems have substantially decreased motor vehicle crash-related injuries and fatalities, but injuries to the lumbar spine still have been reported. Experimental and computational analyses of upright and, particularly, reclined occupants in frontal crashes have shown that the lumbar spine can be subjected to axial compression followe...
Article
Objective Highly automated vehicles may permit alternative seating postures, which could alter occupant kinematics and challenge current restraint designs. One predicted posture is a reclined seated position. While the spine of upright occupants is subjected to flexion during frontal crashes, the orientation of reclined occupants tends to subject t...
Article
Objective This study aims to evaluate the assumption of geometric similitude inherent to equal-stress equal-velocity scaling by determining if scale factors created with different anthropometry metrics result in different scaled injury tolerance predictions. This assumption will be evaluated when equal-stress equal-velocity scaling is employed acro...
Article
Frontal impacts with reclined occupants are rare but severe, and they are anticipated to become more common with the introduction of vehicles with automated driving capabilities. Computational and physical human surrogates are needed to design and evaluate injury countermeasures for reclined occupants, but the validity of such surrogates in a recli...
Article
The use of standardized anthropomorphic test devices and test conditions prevent current vehicle development and safety assessments from capturing the breadth of variability inherent in real-world occupant responses. This study introduces a methodology that overcomes these limitations by enabling the assessment of occupant response while accounting...
Article
This paper reports the development of a test device for replicating unique features of concussion-causing helmet-to-ground impacts. Helmet-to-ground impacts are characterized by an oblique impact velocity vector, preimpact rotational motion of the helmeted head, and an impact into a compliant frictional surface of unknown effective mass. No helmet...
Article
Previous studies indicate that seatbelts may require supplementary restraints to increase their effectiveness in far-side impacts. This study aimed to evaluate the effectiveness of a novel, far-side-specific airbag in restraining and preventing injuries in far-side impacts, and to evaluate the WorldSID's response to the presence of a far-side airba...
Conference Paper
Full-text available
Load limiters at seat track, seat, seat back, and lap belt were investigated to determine their effect on pelvis and lumbar spine loading, using the SAFER human body model and models of a semi-rigid seat and a triple-pretensioned, load-limited belt system. The models were evaluated with four sled tests involving 50 km/h frontal impacts using averag...
Article
Full-text available
Quantifying the whole body response of ATD (anthropomorphic testing device) is important to study the behavior of belted occupant. In a previous study we studied the forward excursion of ATD, PMHS (Post Mortality Human Subject = Cadaver) with standard 3-point belt and Human Volunteer with energy absorbing shoulder belt, and concluded that the excur...
Article
Objective: Up to one-half of drivers swerve before a crash, which may cause vehicle motions that displace an occupant from a normal seated position. How these altered postures affect occupant restraint in a crash is unknown. The goal of this study was to quantify the effect of an initial inboard lean on occupant kinematics in a frontal impact. Meth...
Article
Trilateration and Kalman filtering algorithms have been used in many tracking applications ranging from Global Positioning Systems (GPS) to biomechanics experiments to measure rigid body motion and to identify positioning. Recently, a technique called sonomicrometry was used to measure the deformation of human brain tissue during an injurious impac...
Article
Traumatic brain injuries (TBI) are a substantial societal burden. The development of better technologies and systems to prevent and/or mitigate the severity of brain injury requires an improved understanding of the mechanisms of brain injury, and more specifically, how head impact exposure relates to brain deformation. Biomechanical investigations...
Article
Objective: Knee airbags (KABs) have become increasingly common in the vehicle fleet. Previous studies (Weaver et al., 2013, Patel et al. 2013) showed indications that KABs may be protective for some lower extremity injuries and associated with increased risk for others. Since KABs have become significantly more common in recent model year vehicles,...
Article
This paper presents a detailed characterization of helmet-to-ground impacts in the National Football League. Video analysis was performed for 16 head-to-ground impacts that caused concussions. Average resultant closing velocity was 8.3 m/s at an angle nearly 45° to the surface. Preimpact rotational velocity of the helmet ranged from negligible to a...
Conference Paper
Far-side kinematics and injury are influenced by the occupant environment. The goal of the present study was to evaluate in-vehicle human far-side kinematics, kinetics and injury and to assess the ability of the WorldSID to represent them. A series of tests with five Post-Mortem Human Subjects and the WorldSID were conducted in a vehicle-based sled...
Article
Far-side kinematics and injury are influenced by the occupant environment. The goal of the present study was to evaluate in-vehicle human far-side kinematics, kinetics and injury and to assess the ability of the WorldSID to represent them. A series of tests with five Post-Mortem Human Subjects and the WorldSID were conducted in a vehicle-based sled...
Conference Paper
Full-text available
Automated vehicles introduce the potential for non-traditional seating postures, including various degrees of recline. To date, there have been no human surrogate studies in the literature describing reclined occupant response in frontal or other crashes, which suggests that new biofidelity reference targets are needed to evaluate anthropomorphic t...
Article
Objective: Self-driving technology will bring novelty in occupant seating choices and vehicle interior design. Thus, vehicle safety systems may be challenged to protect occupants over a wider range of potential postures and seating choices. This study aims to investigate the effects of occupant size, seat recline, and knee bolster position on subma...
Conference Paper
Full-text available
Far-side impacts represent 9.5% of all automobile crashes and 8.3% of all MAIS3+ injuries. This type of event generates loads that challenge current restraint systems by setting the occupant in an inward motion. This complex motion, influenced by a number of restraint and impact parameters, often results in a loss of shoulder-to-belt contact. Exist...
Article
Objective: As vehicle safety technologies and evaluation procedures advance, it is pertinent to periodically evaluate injury trends to identify continuing and emerging priorities for intervention. This study examined detailed injury distributions and injury risk trends in belted occupants in frontal automobile collisions (10 o’clock to 2 o’clock) u...
Technical Report
This report presents corridors for the biomechanical response of 10 female cadaver subjects, similar in mass and size to a 5th percentile female, in 30 km/h frontal sled tests performed under the gold standard test conditions. The corridors were based on tests conducted at UVA in 2013 (DTNH22-09-H-00247) and 2016 (DTNH2215D00022).The subjects were...
Article
The introduction of highly automated vehicles will influence occupant seating behavior and seat design, including broader adoption of reclined seating postures. The goal of this study was to perform a preliminary assessment of the usability of two occupant FE models (NHTSA THOR FE, and GHBMC Simplified Occupant) to examine restraint interactions, o...
Conference Paper
Obesity is associated with an increased fatality risk in automobile collisions. The goal of this study was to evaluate the predictive capabilities of the obese human body models via comparison of model simulations to post‐mortem human subject tests from the literature. First, obese post‐mortem human subject sled tests were used to assess the abilit...
Article
Objective: Field data analyses often use either parametric or nonparametric means to describe the relationship between risk and various predictor variables. This study sought to evaluate a hybrid approach using semiconstrained multivariate nonlinear spline-based analysis. Methods: Data were compiled from NASS-CDS years 1998–2015, selecting belted o...
Conference Paper
The introduction of new highly automated vehicles holds the promise to influence occupant seated behaviour and seat design. Different seat orientation with respect to the vehicle, and increased seatback recline angles are some novel factors that may challenge occupant restraint systems currently available in the vehicle fleet. It is unknown, howeve...
Conference Paper
Full-text available
Far-side impacts represent 9.5% of all automobile crashes and 8.3% of all MAIS3+ injuries. This type of event generates loads that challenge current restraint systems by setting the occupant on an inward motion. This complex motion, influenced by a number of restraint and impact parameters, often results in a loss of shoulder-to-belt contact. Reduc...
Article
Full-text available
Background Forced external rotation of the foot is a mechanism of ankle injuries. Clinical observations include combinations of ligament and osseous injuries, with unclear links between causation and injury patterns. By observing the propagation sequence of ankle injuries during controlled experiments, insight necessary to understand risk factors a...
Article
Objective: Evaluating the biofidelity of pedestrian finite element models (PFEM) using post-mortem human subjects (PMHS) is a challenge as differences in anthropometry between PMHS and PFEM could limit a model's capability to accurately capture cadaveric responses. Geometrical personalization via morphing can modify the PFEM geometry to match the s...
Article
Objective: The goal of this study was to explore a framework for developing injury risk functions (IRFs) in a bottom-up approach based on responses of parametrically variable finite element (FE) models representing exemplar populations. Methods: First, a parametric femur modeling tool was developed and validated using a subject-specific (SS)-FE mod...
Presentation
https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/sae2018bgepner_et_al.pdf
Article
Full-text available
Ligament sprains, defined as tearing of bands of fibrous tissues within ligaments, account for a majority of injuries to the foot and ankle complex in field-based sports. External rotation of the foot is considered the primary injury mechanism of syndesmotic ankle sprains with concomitant flexion and inversion/eversion associated with particular pa...
Article
Traumatic brain injuries are one of the least understood injuries to the body. Finite element (FE) models of the brain have been crucial for understanding concussion and for developing injury mitigation systems; however, the experimental brain deformation data currently used to validate these models are limited. The objective of this study was to d...
Conference Paper
Full-text available
Syndesmotic ankle sprains, i.e. injuries to the distal tibiofibular syndesmosis, are debilitating injuries often associated with arduous rehabilitation and recovery. External foot rotation is the primary mechanism of these injuries, but the role of ankle flexion remains poorly understood for both injury patterns and tolerances. The present study ai...
Conference Paper
Full-text available
Development of a sonomicrometry method for measuring in situ human brain deformation during dynamic loading of the head.
Conference Paper
Females are at greater risk of lower extremity injury in automobile collisions compared to males (Rudd et al, 2009, Ye et al 2015, Dischinger et al 2016). While several studies (Yoganandan et al 1996, Funk et al 1998) have investigated injury tolerance of the lower extremity during axial loading (e.g., impact to the bottom surface of the foot resul...
Preprint
Full-text available
Far-side impacts represent 9.5% of all crashes and 8.3% of all MAIS 3+. Consumer groups and manufacturers are gaining interest in evaluating vehicle performance in this crash mode; however there is limited information regarding ATD performance in this loading configuration. Current state of the art dummies are designed to meet biofidelity standards...
Conference Paper
Females have an increased risk for foot and ankle injury in automobile collisions compared to males, a difference in risk that has often been attributed to a difference in footwear [1‐3]. Despite an increased risk of foot and ankle injuries for females, few studies containing female PMHS have been performed to characterise the dorsiflexion response...
Article
The Test Device for Human Occupant Restraint (THOR) 50th percentile male anthropomorphic test device (ATD) aims to improve the ability to predict the risk of chest injury to restrained automobile occupants by measuring dynamic chest deflection at multiple locations. This research aimed to describe the methods for developing a thoracic injury risk f...
Preprint
Full-text available
Rib intrusion is the main injury metric to evaluate thoracic injury in front and side impacts. For years, the WorldSID ATD has evaluated this metric with an IRTRACC system. This system tracks the distance and the angle in the transverse plane between two points: one on the spine, and one on the rib. In recent years another technology has appeared:...
Preprint
Full-text available
Far-side impacts represent 9.5% of all crashes and 8.3% of all MAIS3+. Consumer groups and manufacturers are gaining interest in evaluating vehicle performance in this crash mode, but there is a lack of information regarding the performance of the anthropomorphic test device (ATD) in this loading configuration. Current state-of-the-art dummies are...
Article
Objective: Field data analyses have shown that obesity significantly increases the occupant injury risks in motor vehicle crashes, but the injury assessment tools for people with obesity are largely lacking. The objectives of this study were to use a mesh morphing method to rapidly generate parametric finite element models with a wide range of obe...
Article
Ligament sprains account for a majority of injuries to the foot and ankle complex among athletic populations. The infeasibility of measuring the in situ response and load paths of individual ligaments has precluded a complete characterization of their mechanical behavior via experiment. In the present study a fiber-based modeling approach of in sit...
Article
The goal of this study was to predict the structural response of the femoral shaft under dynamic loading conditions using subject-specific finite element (SS-FE) models and to evaluate the prediction accuracy of the models in relation to the model complexity. In total, SS-FE models of 31 femur specimens were developed. Using those models, dynamic t...
Conference Paper
In December 2015 NHTSA announced the intention to introduce a new, modified USNCAP vehicle test protocol. Among other proposed changes NHTSA has announced the introduction of a new full vehicle crash test, frontal oblique, and the introduction of a new ATD - THOR. In the THOR, ankle xversion and dorsiflexion injuries may be predicted based on the b...
Article
Full-text available
Objective: The goal of this study was to evaluate the biofidelity of the Total Human Model for Safety (THUMS; Ver. 4.01) pedestrian finite element models (PFEM) in a whole-body pedestrian impact condition using a well-characterized generic pedestrian buck model. Methods: The biofidelity of THUMS PFEM was evaluated with respect to data from 3 full-s...
Article
Current state-of-the-art vehicles implement pedestrian protection features that rely on pedestrian detection sensors and algorithms to trigger when impacting a pedestrian. During the development phase, the vehicle must "learn" to discriminate pedestrians from the rest of potential impacting objects. Part of the training data used in this process is...
Article
Full-text available
ABSTRACT Player-to-player contact inherent in many unhelmeted sports means that head impacts are a frequent occurrence. Model-Based Image-Matching (MBIM) provides a technique for the assessment of three-dimensional linear and rotational motion patterns from multiple camera views of a head impact event, but the accuracy is unknown for this applicati...
Article
The purpose of this study was to determine the long-time and transient characteristics of the moment generated by external (ER) and internal (IR) rotation of the calcaneus with respect to the tibia. Two human cadaver legs were disarticulated at the knee joint while maintaining the connective tissue between the tibia and fibula. An axial rotation of...
Article
Objective Advanced occupant protection systems in motor-vehicles (e.g., seat belts and airbags), while widely adopted for front-seat passengers, are either absent or offer disproportionally lower safety to rear-seat passengers in similar crashes. Optimization of advanced restraint systems for the rear-seat environment will require a detailed unders...