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Ford Motor Company introduced the automotive industry’s first second row inflatable seatbelt system in 2011. The system is currently available in the outboard seating positions of the second row of several Ford and Lincoln models. An important consideration for this system is the interaction with child restraint systems (CRS) when it is used to install a CRS or used in conjunction with belt position booster. A novel test methodology to assess the interaction of CRS with Ford and Lincoln inflatable seatbelts through frontal impact sled tests is explained. Details of test methods including construction of additional fixtures and hardware are highlighted. This procedure is designed to enable test labs capable of running Federal Motor Vehicle Safety Standard (FMVSS) 213 testing to adapt this test method, with minimal fabrication, by utilizing existing test benches.

Ford Motor Company introduced the inflatable seatbelt system in 2011 and the system is now available in the second row of several Ford and Lincoln models. An important consideration is the interaction of the inflatable seatbelt system with child restraint systems (CRS). A comprehensive series of frontal impact sled tests, using a standardized test method, was conducted to compare the performance of rear-facing-only CRS installed using an inflatable seatbelt to the same CRS installed using a standard seatbelt. CRS models from several manufacturers in the North American market were tested both with and without their bases. CRABI 12 month old or Hybrid III 3 year old anthropomorphic test devices (ATD) were restrained in the CRS. The assessment included the ability to achieve a satisfactory installation with the inflatable seatbelt, comparisons of ATD and CRS kinematics, CRS system integrity, and comparisons of ATD responses.

In the elderly population, rib fracture is one of the most common injuries sustained in motor vehicle crashes. The current study was conducted to predict the biomechanical fracture responses of ribs with respect to age, gender, height, weight and percentage of ash content. Three-point bending experiments were conducted on 278 isolated rib samples extracted from 82 cadaver specimens (53 males and 29 females between the ages of 21 and 87 years) for 6th and 7th levels of ribs. Statistical analyses were carried out to identify differences based on age and gender. It was found that, in comparison to males, females had significantly lower values for maximum bending moments, slopes of bending moment-angle curves, and average cortical-bone thickness (p < 0.05). Samples of ribs taken from elderly specimens failed at lower values of fracture moments than those from younger specimens, and had lower slopes of bending moment-angle curves, both in males and females (p < 0.05).

NHTSA estimates that more than half of the lives saved (168,524) in car crashes between 1960 and 2002 were due to the use of seat belts. Nevertheless, while seat belts are vital to occupant crash protection, safety researchers continue efforts to further enhance the capability of seat belts in reducing injury and fatality risk in automotive crashes. Examples of seat belt design concepts that have been investigated by researchers include inflatable, 4-point, and reverse geometry seat belts. In 2011, Ford Motor Company introduced the first rear seat inflatable seat belts into production vehicles. A series of tests with child and small female-sized Anthropomorphic Test Devices (ATD) and small, elderly female Post Mortem Human Subjects (PMHS) was performed to evaluate interactions of prototype inflatable seat belts with the chest, upper torso, head and neck of children and small occupants, from infants to young adolescents.

This study evaluated the biomechanical performance of a rear-seat inflatable seatbelt system and compared it to that of a 3-point seatbelt system, which has a long history of good real-world performance. Frontal-impact sled tests were conducted with Hybrid III anthropomorphic test devices (ATDs) and with post mortem human subjects (PMHS) using both restraint systems and a generic rear-seat configuration. Results from these tests demonstrated: a) reduction in forward head excursion with the inflatable seatbelt system when compared to that of a 3-point seatbelt and; b) a reduction in ATD and PMHS peak chest deflections and the number of PMHS rib fractures with the inflatable seatbelt system and c) a reduction in PMHS cervical-spine injuries, due to the interaction of the chin with the inflated shoulder belt. These results suggest that an inflatable seatbelt system will offer additional benefits to some occupants in the rear seats.

Nitro Fuel Funny cars have 7-8,000 hp and travel 330 mph in a quarter mile. These cars experience extreme forces in normal operation. One phenomenon familiar to drag racers is tire shake. Mild cases can cause loss of traction and vision. Extreme cases can cause injury or death. In March of 2007, a study and subsequent revision of the passenger compartment in a Fuel Funny car was performed after a fatal accident due to extreme tire shake. Tire shake on a drag race car normally occurs when the force on the rear tire causes the tire to roll over itself causing a loss of traction and side-to-side vibration. In other cases, if the tire fails at high speed, the tire may partially separate, causing an extreme vibration in the cockpit of the car. The vibration may set up a harmonic in the chassis, which is transferred to the driver since the rear end is bolted directly to the chassis with no suspension to absorb the energy.

Currently, there is great interest in motorsports medicine in measuring driver head impact accelerations by adding small triaxial accelerometers to the communication earpieces worn by drivers. Various studies have attempted to validate the ability of the earpiece accelerometers to accurately measure head accelerations. Those experiments demonstrate success in being able to measure head accelerations on dummies and humans in low severity impacts and non-impact head motion. No study has been performed to ascertain the ability of the earpiece accelerometers to accurately measure rigid body head accelerations of the skull when they are mounted in a human ear canal and subjected to high severity head accelerations. This research was performed to evaluate the frequency response and coupling of the earpiece accelerometers to the human skull using post mortem human subject (PMHS) heads as the most realistic surrogate for the living human.

There has been much debate over “whiplash”-induced temporomandibular joint (TMJ) dysfunction following low-speed, rear-end automobile collisions. While several authors have reported TMJ injury based on case studies post collision, there has been little biomechanical evidence showing that rear-end impact was the primary cause of such injury. The purpose of this study was to measure the relative translation between the upper and lower incisors in cadavers subjected to low-speed, rear-end impacts. High-speed x-ray images used for this analysis were reported previously for the analysis of cadaveric cervical spine kinematics during low-speed, rear-end impacts. The cadavers were positioned at various seatback angles and body postures, producing an overall picture of various seating scenarios.

Race car nets have been used for years to keep the drivers head and arms inside the structure of the race car during an accident. Recent testing by GM Racing has shown that a net placed near the driver's shoulder and head on the right side can significantly reduce head excursion and thereby reduce neck tension in a side impact. The reduced neck tension prevents neck injury and basilar skull fracture. The right side net also improves seat stiffness and reduces seat deflection in side impacts.

The objective of this work was to evaluate a new tool for assessing brain injury. Many race car drivers have suffered concussion and other brain injuries and are in need of ways of evaluating better head protective systems and equipment. Current assessment guidelines such as HIC may not be adequate for assessing all scenarios. Finite element models of the brain have the potential to provide much better injury prediction for any scenario. At a previous Motorsports conference, results of a MADYMO model of a racing car and driver driven by 3-D accelerations recorded in actual crashes were presented. Model results from nine cases, some with concussion and some not, yielded head accelerations that were used to drive the Wayne State University Head Injury Model (WSUHIM). This model consists of over 310,000 elements and is capable of simulating direct and indirect impacts. It has been extensively validated using published cadaveric test data.

A MADYMO model of a racing car and driver was driven by 3-D accelerations recorded in actual crashes. Helmet, belt restraint, and padding characteristics were obtained from dynamics tests. Model results of HIC, head accelerations and neck forces and moments were studied along with driver injuries to provide insight into the efficacy of current injury assessment parameters used with the head and neck of crash test dummies. The results are also used to discuss the kinematics performance of the crash test dummy neck as modeled by the MADYMO version of the Hybrid III midsize male crash test dummy.

Axial loading of the calcaneus-talus-tibia complex is an important injury mechanism for moderate and severe vehicular foot-ankle trauma. To develop a more definitive and quantitative relationship between biomechanical parameters such as specimen age, axial force, and injury, dynamic axial impact tests to isolated lower legs were conducted at the Medical College of Wisconsin (MCW). Twenty-six intact adult lower legs excised from unembalmed human cadavers were tested under dynamic loading using a mini-sled pendulum device. The specimens were prepared, pretest radiographs were taken, and input impact and output forces together with the pathology were obtained using load cell data. Input impact forces always exceeded the forces recorded at the distal end of the preparation. The fracture forces ranged from 4.3 to 11.4 kN.

There are many mechanisms for ankle injury to front seat occupants involved in automotive impacts. This study addresses injuries to the ankle joint involving inversion or eversion, in particular at high rates of loading such as might occur in automotive accidents. Injuries included unilateral malleolar fractures and ligament tears, and talus and calcaneous avulsions. Twenty tests have been performed so far, two of them using Hybrid III lower leg and the rest using cadaveric specimens. The specimens were loaded dynamically on the bottom of the foot via a pneumatic cylinder in either an inversion or eversion direction at fixed dorsiflexion and plantarflexion angles. The applied force and accelerations have been measured as well as all the reaction forces and moments. High-speed film was used to obtain the inversiordeversion angle of the foot relative to the tibia and for following ligament stretch.