Effect of Active Muscles on Astronaut Kinematics and Injury Risk for Piloted Lunar Landing and Launch While Standing.

While astronauts may pilot future lunar landers in a standing posture, the response of the human body under lunar launch and landing-related dynamic loading conditions is not well understood. It is important to consider the effects of active muscles under these loading conditions as muscles stabilize posture while standing. In the present study, astronaut response for a piloted lunar mission in a standing posture was simulated using an active human body model (HBM) with a closed-loop joint-angle based proportional integral derivative controller muscle activation strategy and compared with a passive HBM to understand the effects of active muscles on astronaut body kinematics and injury risk.

Effects of Standing, Upright Seated, vs. Reclined Seated Postures on Astronaut Injury Biomechanics for Lunar Landings.

Astronauts may pilot a future lunar lander in a standing or upright/reclined seated posture. This study compared kinematics and injury risk for the upright/reclined (30°; 60°) seated vs. standing postures for lunar launch/landing using human body modeling across 30 simulations.

Development and Validation of an Active Muscle Simplified Finite Element Human Body Model in a Standing Posture.

Active muscles play an important role in postural stabilization, and muscle-induced joint stiffening can alter the kinematic response of the human body, particularly that of the lower extremities, under dynamic loading conditions. There are few full-body human body finite element models with active muscles in a standing posture. Thus, the objective of this study was to develop and validate the M50-PS+Active model, an average-male simplified human body model in a standing posture with active musculature.

Sensitivity Analysis for Multidirectional Spaceflight Loading and Muscle Deconditioning on Astronaut Response.

A sensitivity analysis for loading conditions and muscle deconditioning on astronaut response for spaceflight transient accelerations was carried out using a mid-size male human body model with active musculature. The model was validated in spaceflight-relevant 2.5-15 g loading magnitudes in seven volunteer tests, showing good biofidelity (CORA: 0.

Simulated Astronaut Kinematics and Injury Risk for Piloted Lunar Landings and Launches While Standing.

During future lunar missions, astronauts may be required to pilot vehicles while standing, and the associated kinematic and injury response is not well understood. In this study, we used human body modeling to predict unsuited astronaut kinematics and injury risk for piloted lunar launches and landings in the standing posture. Three pulses (2-5 g; 10-150 ms rise times) were applied in 10 directions (vertical; ± 10-degree offsets) for a total of 30 simulations.

Brain Strain from Motion of Sparse Markers.

Brain strain secondary to head impact or inertial loading is closely associated with pathologic observations in the brain. The only experimental brain strain dataset under loadings close to traumatic levels was calculated by imposing the experimentally measured motion of markers embedded in the brain to an auxiliary model formed by triad elements (Hardy et al., 2007).

A Reanalysis of Experimental Brain Strain Data: Implication for Finite Element Head Model Validation.

Relative motion between the brain and skull and brain deformation are biomechanics aspects associated with many types of traumatic brain injury (TBI). Thus far, there is only one experimental endeavor (Hardy et al., 2007) reported brain strain under loading conditions commensurate with levels that were capable of producing injury.

Modeling Human Volunteers in Multidirectional, Uni-axial Sled Tests Using a Finite Element Human Body Model.

A goal of the Human Research Program at National Aeronautics and Space Administration (NASA) is to analyze and mitigate the risk of occupant injury due to dynamic loads. Experimental tests of human subjects and biofidelic anthropomorphic test devices provide valuable kinematic and kinetic data related to injury risk exposure. However, these experiments are expensive and time consuming compared to computational simulations of similar impact events.

Risk of thoracic injury from direct steering wheel impact in frontal crashes.

Background: The combination of airbag and seat belt is considered to be the most effective vehicle safety system. However, despite the widespread availability of airbags and a belt use rate of more than 85%, US drivers involved in crashes continue to be at risk of serious thoracic injury. The objective of this study was to determine the influence of steering wheel deformation on driver injury risk in frontal automobile crash.

Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes.

To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated.

The tolerance of the nasal bone to blunt impact.

The nasal bone is among the most frequently broken facial bone due to all types of trauma and is the most frequently fractured facial bone due to motor vehicle collisions. This study reports the results of anterior-posterior impacts performed on male cadavers using a free-falling impactor with a flat impacting surface. The force at fracture onset was determined using an acoustic emission sensor.

The effect of gender and body size on angular accelerations of the head observed during everyday activities - biomed 2010.

Research suggests gender and body size affect head injury tolerance. In this study, angular accelerations and velocities of the head were measured for 18 adult volunteers during typical everyday activities. Peak resultant angular head accelerations and velocities for each subject were compared via T-tests and ANOVAs to determine significant differences based on gender and body size.

Acquiring non-censored pelvic bone fracture data during dynamic side impact loading - biomed 2009.

The purpose of this study was to quantify the strain and fracture timing of the pelvic bones during dynamic side impact loading. A total of 3 high-energy side impact tests, 23.4 kg at 12 m/s, were performed on 3 fresh, previously frozen human male cadavers using a custom pneumatic impactor.

The effect of stress and strain formulations on the representation of biological tissue mechanical properties - biomed 2009.

With the increasing use of computational models there is a growing need to establish and analyze the material properties of biological tissues. The purpose of this study is to analyze and compare the various methods used for reporting stress and strain for biological materials. For this study, three biological materials (bone, sclera, and placenta) were used to compare the effects of reporting stress and strain relationships using various formulations.

The effect of temperature on the mechanical properties of bovine liver - biomed 2009.

Abdominal organ injuries account for approximately 3-5% of all injuries in automobile accidents. Because of incidence of injury, understanding the mechanical properties of these organs is vital to preventing and caring for injuries. Abdominal organs degrade quickly after death and therefore the need to develop appropriate procurement and testing methodologies is imperative.

Biomechanical analysis of pulmonary contusion in motor vehicle crash victims: a crash injury research and engineering network (ciren) study - biomed 2009.

Pulmonary contusion is the most common thoracic soft tissue injury encountered in motor vehicle crashes and is seen in 10-17% of all trauma admissions. This study presents a biomechanical and radiological analysis with the goal of quantifying pulmonary contusion resulting from motor vehicle crashes in order to illustrate the relationships between crash characteristics, contusion severity, and patient outcome. The 20 patients selected for this study were involved in motor vehicle crashes and subsequently enrolled in the Crash Injury and Research Engineering Network (CIREN) program at Wake Forest University Baptist Medical Center.

The influence of airbags on thoracic organ lesion types - biomed 2009.

Thoracic organ injuries account for 13% of all serious injuries to belted front seat occupants in frontal crashes. The rate at which thoracic organ injury occurs and the manner in which the injuries occur has not changed significantly with the inclusion of airbags. This study was based on the injury outcomes of over 28,000 belted occupants in frontal crashes from National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) case years 1993-2007.

Validation of an improved injury device for in vitro study of neural cell deformation - biomed 2009.

Traumatic Brain Injury is hypothesized to occur as a function of the strain and strain rate experienced by neural tissues during a traumatic event. In vitro studies of TBI at the cellular level have used a variety of methods to subject neural cell cultures to potentially injurious strains and strain rates. The Advanced Cell Deformation System (ACDS) has been developed which has the ability to independently control strain and strain rate and can strain cell cultures grown on a stretchable membrane from 0.

Correlating cumulative sub-concussive head impacts in football with player performance - biomed 2009.

The objective of this study was to investigate the effect of cumulative sub-concussive head impacts on football player performance. The helmets of three Virginia Tech football players were instrumented with a six accelerometer sensor capable of measuring head acceleration. Helmets were instrumented for every game during the 2006 and 2007 football seasons.

Evaluation of eye injury risk from projectile shooting toys using the focus headform - biomed 2009.

Half of eye injuries in the United States are caused by a blunt impact and more specifically, eye injuries effecting children often result from projectile shooting toys. The purpose of this study is to evaluate the risk of eye injuries of currently available projectile shooting toys. In order to assess the risk of each toy, a Facial and Ocular Countermeasure Safety (FOCUS) headform was used to measure the force applied to the eye during each hit for a total of 18 tests.

Freezing affects the mechanical properties of bovine liver - biomed 2009.

The need to quantify the mechanical properties of human abdominal organs is becoming increasingly important in the automotive industry due to the large incidence of injuries to these organs as a result of motor vehicle crashes. The need to develop appropriate preservation and testing methodology is of particular importance because of how quickly abdominal organ tissues degrade after death. The purpose of this study was to determine the effects of freezing on the mechanical properties of bovine liver parenchyma in uni-axial tension.

In situ measurement of achilles tendon tension during dorsiflexion - biomed 2009.

The objective of this study was to develop a methodology to measure the tension of the Achilles tendon in cadavers during dorsiflexion. The Achilles tendon was instrumented with a customized load cell designed to measure tension. The leg was inverted and secured in a custom testing apparatus designed to invoke dorsiflexion of the foot.