Methods for Evaluating Occupant Kinematics and Seatbelt Use

1 Copyright © 2011 by ASME

Proceedings of the ASME 2011 International Mechanical Engineering Congress & Exposition IMECE2011

November 11-17, 2011, Denver, Colorado, USA

IMECE2011-64736

METHODS FOR EVALUATING OCCUPANT KINEMATICS AND SEATBELT USE DURING A COLLISION

John E. Hinger Hinger Engineering, Inc. Irvine, California, USA

ABSTRACT

Vehicular accident investigators are frequently called upon to determine seatbelt system usage and injury mechanisms for vehicle occupants. An evaluation method using an exemplar vehicle and a surrogate occupant can be used in helping to make this determination. An understanding of the collision characteristics, injuries sustained and forensic evidence located within the vehicle can be used with a surrogate occupant in an exemplar vehicle to determine seatbelt system usage, injury mechanisms and occupant kinematics.

INTRODUCTION

In the process of understanding the mechanism of injuries to vehicular occupants, accident investigators need to determine how and where the occupant was positioned within the vehicle when the collision occurred and what they could have interacted with in their surroundings. In modern vehicles, the occupant may be situated in close proximity to numerous interior parts within the vehicle and to the exterior of the vehicle. The interior parts generally surrounding an occupant include windows, consoles, dash boards, steering wheel, sun visor, headliner, roof rails, seats, airbags and of course seatbelt systems. After examining the subject vehicle, questions about the seatbelt system usage of the occupant may become evident: Was the occupant wearing the available seatbelt? Was the occupant using the seatbelt properly, or was the shoulder belt behind the occupant’s back or under their arm? Could the occupant have been sitting on the seatbelt or lying down on the seat with the seatbelt on? Was the seatback reclined? Was the occupant seated “normally” or out of position? Also, questions about the injuring vehicle part may manifest: Can the injured body part contact the suspected injuring surface when the occupant is properly restrained? The position of the occupant in the vehicle may also be an issue.

Previous authors have published papers on the forensic evidence that can be found by inspecting seatbelt systems after a collision [1,2,3]. This paper details other forensic evidence available in the vehicle. It also summarizes techniques to determine the occupants’ kinematics and injury mechanism(s) within the vehicle and whether a seatbelt system was worn properly. Through the use of exemplar vehicle and surrogate occupant studies, we have applied a method for answering these and other questions.

METHOD FOR DETERMINING OCCUPANT KINEMATICS AND SEATBELT USE

The gathering and review of certain types of information prior to studying an exemplar vehicle and surrogate occupant can be beneficial in determining the occupants’ kinematics, seatbelt usage and injury mechanism(s). This information may include an inspection of the vehicle, review of medical and accident records, an understanding of the collision dynamics, witness statements and collision photographs. THE VEHICLE INSPECTION

The subject vehicle should be thoroughly examined for forensic evidence, on both the interior and exterior. In certain situations where the vehicle may no longer be available, photographs of the vehicle can shed some light on what interactions the occupant may have had within the vehicle. The examination of the subject vehicle includes determining the make, model and year of the vehicle; and whether there are any special features that vehicle incorporates, for example bench or bucket seats, seating trim level, sunroof, automatic or manual transmission. It should also be noted if any aftermarket equipment is installed


in the vehicle. By gathering this information, the investigator can be assured of evaluating the surrogate occupant in a similar environment. During the subject vehicle inspection, a number of settings or positions within the vehicle should be documented, including: seat position on the tracks, seatback angle and other seat adjustments, seatbelt guide loop position on upper adjustable anchorage, steering wheel tilt position, gear shift lever position, and side window glass or window track positions. Also, it is important to note if the vehicle is equipped with frontal, side, or side curtain airbags and whether they deployed during the collision. After documenting the identifying information of the vehicle, its features and the positions of interior components, a forensic evaluation can be made. The forensic evaluation includes examining all of the interior components in the vehicle surrounding the occupant’s area to determine if there is evidence to indicate that they were interacted with or loaded during the collision by the occupants, or became damaged as a result of the collision or some other condition. Identification of subtle or unusual forensic evidence will be dependent upon the level of experience the investigator has. The types of evidence likely to be found include abrasions, scuffs, fractured, ripped or deformed pieces, hair deposits, blood stains, body fluid or matter, and transfer marks. Collision scene photos can also be used to further identify forensic evidence that may no longer exist or may have been changed since the date of the collision. The scene photos can also be used to see if there were items in the vehicle at the time of collision, or if there are marks in the vehicle that did not exist immediately after the collision. The scene photos can also be used to see if anything changed with the subject vehicle since the scene photos were taken. The following examples will demonstrate some of the most common types of forensic evidence and areas within a vehicle where it may be found after a collision. The examples are merely presented to demonstrate some types of forensic evidence that may be found in a vehicle and it is up to the investigator to interpret what may have caused this evidence and its relevancy to the occupant. The forensic evidence that can be found in vehicles may be more subtle or substantial than the examples provided in this paper. These examples are not intended to be inclusive of every type or location of forensic evidence that may be found in a vehicle, however, it emphasizes the significance of occupant contacts with the vehicle during the collision. Head Liner – Abrasions or impacts may be found from head contacts with the headliner and individual hairs are frequently found embedded into the abrasion or found on the headliner area. As seen in Figure 1, an abrasion was caused on the headliner as an occupant was ejected out the window. The direction of abrasions can provide the investigator with

information on the direction the occupant was moving when the abrasion occurred. Sunvisor – Deformation to the rear edge (edge toward occupant) may be caused by an occupant contacting the sunvisor. Figure 2 shows an abrasion on the underside from the occupant moving toward the windshield. An inspection of the visor vanity mirror should also be done to determine if it broke from contact to the sunvisor. The extent and location of forensic evidence to the sunvisor can indicate the amount of occupant involvement with it and could be a good indicator of the direction of occupant movement.

Figure 1: Occupant contact mark on headliner

Figure 2: Abrasion on sunvisor Windshield – The front windshields of passenger vehicles are laminated. Laminated glass consists of a plastic laminate layer that is sandwiched between two layers of glass. When the windshield is impacted, the laminate layer resists penetration by the object as the glass in the impact area fractures. This fractured glass area usually exhibits a “starburst” fracture


pattern where the impact occurred. If the impacting force is high, the “starburst” fracture may even protrude outward, as shown in Figure 3. The occupants head, arms and hands are the most likely parts of the occupant to contact the windshield in frontal collisions. Smaller starburst fracture patterns may indicate a less forceful head impact, impact from a different body part or other object in the vehicle. The location of the “starburst” fracture pattern is important because it provides information on the direction on the occupants’ movement away from their starting position. Carefully examine the glass fragment pattern for evidence of hair, blood or other human tissue. Other causes of windshield fracture patterns include airbags and airbag module covers. Also, it is important to note that over time the laminate in the fractured windshield relaxes and may bow inward or even separate and fall into the vehicle.

Figure 3: Protruding starburst fracture pattern on passenger side of windshield Rear View Mirror – The rear view mirror can be disrupted from its position, as shown in Figure 4, or dislodged from the windshield if it is impacted during a collision. This damage may include a fractured mirror surface, deformation to the tubular mount or abrasions on the trim surrounding the mirror. The deformation pattern done to the tubular mount may provide information on the direction of impact to the mirror. The deployment of the frontal airbag system may also disrupt the rear view mirror. Side Window – In most passenger vehicles, the side windows are made out of tempered glass. Tempered side glass may fracture as a result of occupant impact or vehicle damage. Noting position of glass fragments in the window channel or the window track position in the door can give the investigator some indication as to the up or down position of the window at the time it was broken out. If the glass is not evident in the

channel, the level of the window regulator in the door can help the investigator understand the window position. Determining window position may be helpful in determining when an occupant was ejected from the vehicle. Also, if the window has not broken out, there may be smudges or fluid marks from the occupant on the interior surface of the glass.

Figure 4: Rearview mirror disrupted to the right Window and Door Molding – If an occupant were ejected or partially ejected out a window opening during a collision, there could be forensic evidence of their path out of the window. This evidence is most likely going to be found in the molding and trim areas surrounding the window opening. Figure 5 shows a scuff an occupant made on the upper door trim and damage to the lower window molding as they were ejected out the window.

Figure 5: Occupant scuff on upper door and damage on lower window molding leading out the window Door Panels – The door panels may be scuffed, scratched, fractured or deformed by occupant loading. If an occupant has


sufficient lateral force when they contact the door they can bow the door structure outward or damage the trim. Steering Wheel & Column – An occupant may impact the steering wheel during a collision. This contact may include abrasions or cut marks on the steering wheel rim or actual bending of the wheel rim as shown in Figure 6. An occupant may also stroke the energy absorbing steering column from their impact with the steering wheel assembly. Steering column stroking can be evaluated by measuring the steering column capsule bracket movement or the length of the column. If the steering column sustains sufficient loading, the capsule brackets will separate from their mounts and the steering assembly will lie loosely in the dash area.

Figure 6: Steering rim deformation and column movement Lower Dash Area – The lower dash area is frequently contacted by the occupants’ knees during frontal type collisions. The extent of the damage may be dependent upon the amount of loading from the occupant. On many modern vehicles, there is a knee bolster within the lower dash to help absorb some of the occupant’s energy. The knee bolster helps resist the occupant’s lower torso’s forward movement. When sufficient resistance force is applied by the occupant, the knee bolster and/or lower dash area can deform. A lighter contact in the lower dash area by the occupant may only result in an abrasion. Also, it’s not unusual to find clothing transfer marks in abrasions. The position of the lower dash abrasions and damage can provide information on where the occupant’s legs were positioned. As shown in Figure 7, an occupant’s knees impacted the center and right portions of the glove box area of the lower dash. Center Console & Gear Shift – The center console and gear shift area may be displaced, fractured, scuffed or separated from the vehicle from interaction with an occupant moving laterally across the vehicle.

Figure 7: Lower dash area on passenger side of vehicle Seats – The seats may exhibit deformation to the seatback frame, recliner device, seat bottom frame or seat tracks. Documentation of the seat position at known locations on the seat track and seatback position can assist the investigator in determining the extent of deformation the seat sustained during the collision. Forensic evidence on the seat material may include abrasions, perforations, tears or indentations. An unbelted occupant or unrestrained cargo in the rear of a vehicle may impact the back of front seats in a frontal collision and contribute to the occupant kinematics or injury mechanism to the front seat occupant. As seen in Figure 8, an abrasion was left on the seatback leather from an occupant who had his shoulder belt webbing behind his back while the lap belt was loaded in a frontal collision.

Figure 8: An improperly positioned shoulder belt mark on driver’s seatback Airbags – Modern passenger vehicles may contain numerous types of airbag systems including driver and passenger frontal


airbags, side impact thoracic or thoracic/head airbags, knee bolster bags or side curtain airbags. Most vehicles contain multiple airbag systems. Interactions between an occupant and the airbag may leave scuffs on the airbag material. In some circumstances, an occupant wearing cosmetics may transfer her make-up to the airbag surface, as shown in Figure 9. The location of these markings can give the investigator information on where and how the occupant contacted the airbag. The airbag module covers should also be inspected to determine if the occupant made contact with the cover before the airbag was fully inflated.

Figure 9: Occupant’s make-up transfer onto driver airbag Seatbelt System – Passenger vehicles contain numerous types of seatbelt systems. Although each of these seatbelt systems may be unique to a specific vehicle, the inspection techniques presented here can be adapted by an investigator to evaluate any seatbelt systems for forensic evidence. A typical seatbelt system primarily consists of webbing, retractor, guide loop, latch plate, buckle and anchorages. The seatbelt system is examined for forensic evidence, especially in the areas associated with loading by seatbelted occupants. Specifically, the webbing, latch plate, guide loop and anchorages. Other authors have documented forensic evidence that are considered “load” marks from usage during a collision and markings that are considered normal wear marks on the seatbelt system from usage over the life of the vehicle [1,4]. Some of the items for an accident investigator to consider when inspecting seatbelt system hardware include: vehicle and web sensitive locking retractors, load limiting retractors, retractor and buckle pretensioners, energy management loops, webbing stretch, anchorage deformation, and buckle operation. Also, as more vehicles include electronic data recorders for airbag systems, there is an increased possibility that the occupant’s usage of the seatbelt system was recorded.

The location of any forensic evidence on the webbing is very important to determine if and how the occupant was wearing the seatbelt. Forensic evidence on the webbing can include transfer marks from the coating on guide loop or latch plate, cinch marks from cinching latch plates, web grabber marks, abrasions, “roping” or bunching of webbing, tears, “pricked” fibers from glass fragments and stains. In Figures 10 and 11, latch plate and guide loop transfer marks are located on the webbing. These transfer marks can be used by the investigator during an exemplar vehicle and surrogate occupant evaluation method to determine how the seatbelt was adjusted on the occupant.

Figure 10: Transfer mark on webbing from latch plate

Figure 11: Transfer mark on webbing from guide loop As previously demonstrated in Figure 8 the seat can exhibit abrasions from loading of a lap belt when the shoulder belt webbing is behind the occupants back and in contact with the seat back. Also, as shown in Figures 12 and 13, the seatback in the rear of an SUV can exhibit forensic evidence on the webbing and seatback from an occupant wearing the shoulder belt webbing behind her back and cargo in the rear of the SUV loading the seat back. Bunching of seatbelt webbing in the


latch plate can be seen in Figure 14. When transfer marks are found on webbing from the latch plate or guide loop, it is important, if possible, for the investigator to determine which direction the webbing passed over the seatbelt hardware piece. For example, did the transfer mark in the webbing shown in Figure 10 start at 37 inches and end at 39 inches, or did it start at 39 inches and end at 37 inches? As seen in Figure 15, an investigator may be able to identify the direction of webbing movement by the inspection of the webbing bearing portion of the hardware (i.e. latch plate and guide loop) where the transfer occurred.

Figure 12: Transfer mark on webbing from seat back and seatback damage from seatbelt

Figure 13: Close up of seatback damage, also note curvature to seatback due to seatback frame deformation from loading of the seatback while seatbelt webbing restrained seatback

Figure 14: Webbing bunched in latch plate

Figure 15: Webbing movement through latch plate

Also, the lack of forensic evidence in the vehicle can be important to understand what couldn’t have happened. For example, the lack of forensic evidence on the seatbelt webbing, latch plate and guide loop may indicate that the occupant wasn’t wearing the seatbelt during the collision. All of these are examples of forensic evidence from occupant interaction with the seatbelt and are representative of some of the types of forensic evidence that an accident investigator may find during a vehicle inspection. These examples should be used by the investigator to appreciate that a thorough inspection of the subject vehicle, and all of its components, is helpful to determine what forensic evidence may or may not exist. Each collision is unique and not all forensic evidence identified in this paper may be found after each collision. Also, depending upon the circumstances of the collision, other forensic evidence is likely to be found. The correct interpretation of the forensic evidence will likely be dependent upon the investigators level of experience.

Webbing movement


THE OCCUPANT

It is optimal to know certain characteristics about the occupant at the time of the collision. The occupant characteristics that are important include gender, age, height and weight at the time of the collision. Other occupant characteristics that can be helpful include their seated height, pant inseam, sleeve length, waist size and hair color. Knowing what clothing the occupant was wearing at the time of the collision may also be important. A colored transfer mark on an interior component may correspond to contact by part of the occupant that was clothed in that color. A clothing transfer mark on webbing, as seen in Figure 16, confirms an interaction between the occupant and webbing. Clothing can also have an effect on how much seatbelt webbing is extended from the retractor to get around the occupant. Bulkier clothing will require more webbing than tight fitting clothing. In lower speed events, the frictional characteristics of different fabrics may be important.

Figure 16: Clothing transfer mark on webbing The occupant’s posture and seat adjustment position at the time of the collision are also significant. This information can be determined during the vehicle inspection as indicated above or by getting the subject occupant, or a surrogate occupant, to position the seat where it would be comfortable for him/her. If collision scene photographs or early vehicle inspection photographs are available, they can be used to compare the position determined by the occupant or surrogate. The investigator should then collect all of the available details concerning the type, location and extent of all injuries the occupant sustained in the collision. This information is important in determining how the occupant sustained these injuries during the collision. Sometimes it can be helpful to diagram these injuries on a two-dimensional or three-

dimensional scale human model to determine injury patterns that otherwise may not be obvious. THE COLLISION

To determine the occupants’ kinematics and seatbelt use during a collision, it is necessary to have an understanding of the collision being studied. At a minimum, a basic understanding of the accident reconstruction is necessary to understand the direction of forces the vehicle and occupant may experience. In a single impact collision, an understanding of the collision could include the subject vehicle’s Delta-V (change in velocity), PDOF (principle direction of force), impact location on the vehicle and any pre-impact actions or post impact movements for the vehicle. For multiple impact collisions, the same type of information for the single collision is desirable for each of the multiple impacts plus information about movements between collisions. Some useful information to understand the dynamics of rollover collisions includes the number of rolls, trip mechanism, which side of the vehicle is at the leading edge of the roll, how the vehicle rolls, vehicle roll rate, location of any ground impacts on vehicle and the pre-rollover maneuvers of the vehicle. A full accident reconstruction analysis can provide more details on the extent of forces the occupant experienced and the direction of these forces. Through this basic understanding of the collision forces acting on the vehicle and the occupant, an investigator can evaluate the occupant’s kinematics, seatbelt usage and injury mechanism. The investigator should be aware of the dynamics of a collision through the study of crash test films and/or conducting crash and impact sled tests. Through this knowledge, the investigator will better understand the compliance and fidelity of the occupant, the performance of the seatbelt system and the impact characteristics of the vehicles structures and other components. THE EXEMPLAR VEHICLE

Exemplar vehicles are selected by matching the subject vehicle by make, model, model year and substantially similar features. A sister vehicle can be used if a vehicle of the actual make and model is unavailable. Information regarding sister vehicles and model year range can be obtained from Neptune Engineering [5]. Similarity of the configuration of interior parts surrounding the occupant in the subject vehicle and the exemplar vehicle should be confirmed. The Mitchell Guide [6] can be consulted when questions regarding interior components arise. Forensic evidence found on the subject seatbelt system and/or in the interior can be marked inside the exemplar vehicle to determine their relationship to the surrogate occupant. For example the latch plate and guide loop transfer marks on the webbing can be used to determine how the seatbelt was positioned around the occupant at the time of the collision.


These markings can be used to determine if the seatbelt system was used properly. When marking seatbelt webbing for the exemplar vehicle demonstration, it is important to not only locate forensic evidence at the correct dimensional location, but also on the side of the webbing that it is found. As seen in Figure 17, a latch plate transfer mark is represented on the webbing with blue tape, a clothing transfer mark on the lap belt webbing is represented with yellow tape and a seatback transfer mark on the webbing is represented with blue tape (on the back side of the webbing - out of view in the picture). With the use of an exemplar vehicle, it is clear that the forensic evidence (transfer marks) on the webbing demonstrate that the shoulder belt portion of the webbing was behind the occupant’s back at the time of the collision and was pulled tighter as the lap belt webbing was loaded by the occupant. Figure 17: Seatbelt forensic evidence positions indicated by colored tape on the webbing THE SURROGATE OCCUPANT

Surrogate occupants are matched to the subject vehicles occupants by gender, age, height and weight. Attempts should be made to match the surrogate as closely as possible to the vehicle occupants. In cases where photographs of the subject vehicle occupant(s) are available, an attempt can be made to match a specific body habitus. Surrogates can be obtained through a web site, through personal contacts, through a company database or through a modeling or casting agency. Occasionally, when detailed information about the subject occupant is not available, anthropometric data from growth

charts, databases such as GEBOD or statistical studies can be used to approximate the subject occupant [7, 8]. THE EXEMPLAR VEHICLE AND SURROGATE OCCUPANT EVALUATION METHOD

The exemplar vehicle interior is configured to match the subject vehicle interior as closely as possible, paying attention to the seat and steering wheel position. The surrogate is then positioned in the seat to simulate the occupant’s normally seated position. The seat belt is then positioned around the surrogate. As seen in Figure 18, the location of the latch plate, guide loop and the amount of webbing can be determined for a normally seated surrogate.

Figure 18: Webbing position on normally seated surrogate Comparing the location of forensic evidence found on the seatbelt webbing may indicate that a guide loop transfer mark occurred at some distance greater than that of a normally seated occupant. When this occurs it is necessary for the investigator to determine possible seating and posture positions for the surrogate occupant to better understand how the forensic evidence may have occurred. As shown in Figure 19, the occupant could have been leaning forward causing more webbing to be extended from the retractor when the forensic evidence occurred. There may be multiple occupant positions or postures for the occupant that could lead to the forensic evidence location that was found in the subject vehicle. When the occupant position is unknown or in question, the surrogate can be placed in various positions or postures and the seatbelt lengths can be recorded. Occasionally, a seat position may be unknown or questionable. In those cases, one or more positions of comfort for the surrogate can be used. If post collision photographs are available they can be used to determine the seat position after the collision. Caution should be exercised when using photographs taken after the collision


because sometimes rescue personnel move the seat during extrication of the occupant from the vehicle.

Figure 19: Webbing position on out of position surrogate A clamp can be placed on the seat belt webbing to limit extraction of webbing from the seat belt retractor and to simulate lock-up from braking or collision forces. The limits of occupant excursion can then measured and recorded. Also important in an exemplar vehicle and surrogate occupant evaluation is the distance between various occupants’ body parts and the vehicle interior. Examples of some of these measurements are shown in Figures 20, 21 and 22. Next, the motion of the occupant as a result of the vehicle dynamics can be examined. The occupant can be asked to assume a position consistent with his/her expected motion given the forces acting on the vehicle during the collision. Any significant interaction (or lack of interaction) of a body part with a vehicle part should be noted, as well as the distance to interior components of interest to the investigator. For example, the sunvisor may exhibit damage from occupant contact during the collision, so the distance from the occupants head to the sunvisor should be documented. An evaluation should be done for each piece of forensic evidence documented by the investigator during their inspection of the subject vehicle. Occasionally, it is necessary to evaluate two or more occupants in the same vehicle. In these cases, the occupants should be selected based on similar criteria to the subject occupants. The occupants can be seated according to known, measured seating position or into a position (or positions) of comfort for their size. Any interactions between the occupants based on movement or injury location could then be noted.

Figure 20: Distance from chest to steering wheel hub/airbag

Figure 21: Distance from face to upper steering wheel rim

Figure 22: Distance from left knee to lower dash area


DISCUSSION

The exemplar vehicle and surrogate occupant evaluation method can be used to determine what happened, what could have happened and what could not have happened during a collision. Although this is a static evaluation, an investigator with a thorough understanding of the impact dynamics of a collision can use this method as an effective tool in determining what occurred during the collision. This is accomplished by evaluating what is within reach of the occupant and what movements the occupant would need to match the forensic evidence found in the subject vehicle. By determining the distance between occupant contact points in the interior and the corresponding body part that made the contact, the investigator can make a reasonable estimation of the forces and seatbelt conditions necessary for the occupant to reach that interior location. By evaluating the extent of the occupant contact marks and their direction in the interior of the vehicle the investigator can determine the occupant’s kinematics during the collision. Seatbelt usage is a key factor in determining the mechanism of injury in automotive trauma. An occupant’s own comments about his seatbelt use may be unreliable or even non-existent if the occupant is deceased. There may be comments that the occupant “always” wears his belt or “is religious” about putting it on. The use of forensic evidence on the seatbelt system and in the vehicle is the best indicator of whether or not the occupant was wearing his/her seatbelt during a collision. However, it is beneficial to have another tool to determine whether a seatbelt was worn and worn properly during the collision. Using this method, witness marks on subject seatbelts are compared to the position of the latch plate, guide loop and location of the webbing around the surrogate occupant in the exemplar vehicle. Also, the posture, position and the extent of occupant excursion can be determined. This method can also be used to demonstrate the extent of occupant excursion possible if the belt system was worn properly to demonstrate its injury mitigation potential. The location of the forensic evidence could also indicate the occupant was not seated properly at the time of the collision and received less than optimal protection from the seatbelt system. For example, he/she may have been leaning forward prior to the collision, extending more webbing out of the seatbelt system and positioning themselves closer to interior components. Similar evaluations can be done with child occupants and different types of child restraint system. A surrogate child may be placed in a child restraint seat similar to one that was used during the collision to determine the mechanism of injury to the child. Child restraint seats may also be used to show how a child would be restrained in the vehicle seatbelt system as compared to a child restraint system.

The exemplar vehicle and surrogate occupant evaluation method is an effective and repeatable method for determining occupant kinematics, contact points reachable within the vehicle, injury mechanism(s) and if or how the seatbelt system was worn during the collision. CONCLUSION

The exemplar vehicle and surrogate occupant evaluation methods contained within this paper allows an investigator to determine how a seatbelt may have been worn and how the occupant may have interacted with the vehicle. These results can be extrapolated to the injury mechanism environment, along with the accident reconstruction analysis. This evaluation method is repeatable and yields scientifically sound information for evaluating the occupant’s seatbelt use, kinematics and their interaction with the vehicle.

REFERENCES

1. Moffat, C.A.; Moffatt, E.A., and Weiman, T.R., “Diagnosis of Seat Belt Usage in Accidents,” SAE Paper No. 840396, 1984.

2. Tanner, C.B.; Durisek, N.J.; Hoover, T.D., and Guenther, D.A., “Automotive Restraint Loading Evidence for Moderate Speed Impacts and a Variety of Restraint Conditions,” SAE Paper No. 2006-01-0900, 2006.

3. Bready, J.E.; Nordhagen, R.P.; Kent, R.W., and Jakstis, M.W., “Characteristics of Seat Belt Restraint Markings,” SAE Paper No. 2000-01-1317, 2000.

4. Bready, J.E.; Nordhagen, R.P., and Kent, R.W., “Seat Belt Survey: Identification and Assessment of Noncollision Markings,” SAE Paper No. 1999-01-0441, 1999.

5. Neptune Engineering, Inc., P.O. Box 1597, Clovis, CA 93613.

6. Mitchell International, Inc., San Diego, CA. http://www.neptuneeng.com

http://www.mitchell.com 7. Gordon, C.C.; Bradtmiller, B.; Churchill, T; Clauser,

C.E.; McConville, J.T.; Tebbetts, I., and Walker, R., “1988 Anthropometric Survey Of U.S. Army Personnel: Methods and Summary Statistics,” Anthropology Research Project, Inc. 503 Xenia Avenue, Yellow Springs, OH 45387, September 1989.

8. Tilley, A.R., The Measure of Man and Woman, 2002.

http://www.mitchell.com/�

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Methods for Evaluating Occupant Kinematics and Seatbelt Use