Airbag deployments: the Canadian experience

Estimation of Injury Limits at Vulnerable Impact Locations Along the Forearm Via THUMS AM50 Finite Element Model at Airbag Loading Rates

Side and frontal airbag deployment represents the main injury mechanism to the upper extremity during automotive collisions. Previous dynamic injury limit research has been limited to testing the forearm at either the assumed most vulnerable location to fracture, the distal 1/3rd, or the midpoint. Studies have varied the surface to which impacts were applied, with no clear consensus on the site of greatest vulnerability. The unpredictability of airbag impact location, especially with altered hand positioning, limits the effectiveness of existing forearm injury limits determined from impacts at only one location. The current study quantified the effect of impacts at alternative locations on injury risk along the forearm using the THUMS FE model. Airbag-level impacts were simulated along the forearm on all four anatomical surfaces. Results showed the distal 1/3rd is not the most vulnerable location (for any side), indicating forearm fracture is not solely driven by area moment of inertia (as previously assumed). The posterior forearm was the weakest, suggesting that current test standards underestimate the fracture risk of the forearm. Linear regression models showed strong correlation between forearm fracture risk and bone geometry (cross-sectional area and area moment of inertia) as well as soft-tissue depth, potentially providing the ability to predict forearm injury tolerances for any location or forearm size. This study demonstrated the forearm's vulnerability to fracture from airbag deployments, indicating the need for safety systems to better address injury mechanisms for the upper limb to effectively protect drivers.

Combining tape stripping and non-invasive reflectance confocal microscopy : an in vivo model to study skin damage

BACKGROUND

Evaluation of (immuno)histological and cell biological changes in damaged skin requires often an invasive skin biopsy, making in vivo models inappropriate to study skin damage. Reflectance confocal microscopy (RCM) might overcome this limitation. Therefore, we evaluated the use of a tape-stripping model in combination with RCM to provide morphological data on skin damage and recovery.

METHODS

In 25 volunteers, a tape-stripping stimulus was applied. The skin was imaged with RCM during 1 week and 3 mm punch biopsies were obtained.

RESULTS

Strong correlations between epidermal thickness determined by RCM and conventional histological measurements were found. RCM thickness measurements correlated well with epidermal proliferation. The 10× or 15× repeated tape-stripping resulted in skin damage similar to acute stripping. Mild repeated tape-stripping showed no skin damage.

CONCLUSION

Overall, we demonstrated that non-invasive RCM in combination with tape-stripping could be used as model to obtain morphological and cell biological data on skin-material interactions.

Children, automobile restraints and injuries

Injuries are the most common cause of death for Canadians aged one to 18 years, and 50% of injury deaths in this age group involve an automobile. Evidence suggests that 71% reduction in deaths and a 67% reduction in injuries can be achieved when child safety seats are used properly. This article reviews the recommended restraints for children by weight group and describes the proper position for children. Detailed case examples of car crashes are described to illustrate the dangers of incorrectly used or no restraint.

The association between restraint system and upper extremity injury after motor vehicle collisions

OBJECTIVES

This study was designed to investigate the relationship between upper extremity (UE) injuries and occupant restraint systems among front seat occupants who were involved in frontal motor vehicle collisions (MVCs).

DESIGN

Case-control.

SETTING

The 1995 through 2002 National Automotive Sampling System (NASS) Crashworthiness Data System (CDS).

PARTICIPANTS

Subjects were identified from the NASS-CDS. All cases sustained an UE injury with a > or = 2 Abbreviated Injury Scale Score.

OUTCOMES

Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated comparing risk of UE in 3 mutually exclusive restraint system groups (seatbelt-only, airbag-only, seatbelt-airbag-combined) to the unrestrained group. Data analysis was adjusted for significant occupant, vehicle, and collision characteristics.

RESULTS

Seatbelt-only occupants had a reduced UE injury risk (OR, 0.41; 95% CI, 0.22-0.76). Near null associations were found for airbag-only (OR, 1.1; 95% CI, 0.68-1.76) and seatbelt-airbag-combined (OR, 0.97; 95% CI, 0.56-1.69).

CONCLUSION

The results of this study suggest that UE injuries may become more common as a result of MVCs as the proportion of airbags in motor vehicles increases.

Severe upper extremity injuries in frontal automobile crashes: the effects of depowered airbags

BACKGROUND

The purpose of this study was to determine the effects of depowered frontal airbags on the incidence of severe upper extremity injuries.

METHODS

The National Automotive Sampling System database files from 1993 to 2000 were examined in a study that included 2,413,347 occupants who were exposed to an airbag deployment in the United States.

RESULTS

Occupants exposed to a depowered airbag deployment were significantly more likely to sustain a severe upper extremity injury (3.9%) than those occupants exposed to a full-powered airbag deployment (2.5%) (P=.01). Full-powered systems resulted in an injury distribution of 89.2% fractures and 7.9% dislocations compared with depowered systems with 55.3% fractures and 44.3% dislocations.

CONCLUSIONS

Although depowered airbags were designed to reduce the risk of injuries, they appear to have increased the overall incidence of severe upper extremity injuries through a shift from long bone fractures to joint dislocations.

The Effects of Depowered Airbags on Skin Injuries in Frontal Automobile Crashes

The purpose of this study was to determine the effects of depowered frontal airbags on the incidence of skin injuries. The National Automotive Sampling System database files from 1993 to 2000 were examined in a study including 2,246,524 occupants exposed to airbag deployment in the United States. There was no significant difference between full-powered and depowered airbags, with 60.2 percent of those exposed to a full-powered deployment sustaining a skin injury versus 59.5 percent of occupants exposed to a depowered airbag (p = 0.19). Whether occupants were exposed to a full-powered airbag (1,936,485 occupants) or a depowered airbay (310,039 occupants), the majority of skin injuries were to the upper extremity and the face. Regardless of airbag power, the overwhelming majority of the skin injuries were minor (99.8 percent). There was not a significantly greater risk of injury from any source for occupants exposed to a depowered airbag or a full-powered airbag (p = 0.87). The data suggest that the implementation of depowered airbags did not affect the number, seriousness, location, or source of skin injuries.

The effects of depowered airbags on eye injuries in frontal automobile crashes

The purpose of this study was to investigate eye injuries resulting from frontal automobile crashes and to determine the effects of depowered airbags. The National Automotive Sampling System database files from 1993 to 2000 were examined in a 3-part investigation of 22 236 individual crashes. Of the 2 103 308 occupants exposed to a full powered deployment, 3.7% sustained an eye injury compared to 1.7% of the 310 039 occupants exposed to a depowered airbag deployment. Occupants were at a significantly higher risk to sustain an airbag-induced eye injury when exposed to a full powered airbag compared with occupants exposed to a depowered airbag deployment ( P = .04). Approximately, 90% of the eye injuries in full powered airbag deployments were caused by the airbag, compared to only 35% of the depowered airbag eye injuries.

Temporomandibular joint pain following airbag deployment on the face: a case report

Varieties of injuries have been reported as a result of the deployment of the airbag/s following road traffic accidents. The purpose of this case-report is to present a physiotherapist's perspective of a patient who was diagnosed as having temporomandibular pain and dysfunction following the deployment of the airbag on the face and its implications for the dental profession. The patient was assessed using a modified Maitland assessment procedure to establish the diagnosis and the treatment consisted of Maitland mobilisation techniques, pulsed short wave diathermy and ultrasound as and when indicated directed to the upper cervical spine. The outcome of this case-report suggests that the temporomandibular symptoms presented by this patient were of cervical origin. Therefore, it is suggested that the cervical spine should be routinely examined in patients presenting with temporomandibular pain and dysfunction following trauma and early referral to physiotherapy may facilitate early recovery.

The effects of airbag deployment on severe upper extremity injuries in frontal automobile crashes

The purpose of this study was to investigate severe upper extremity injuries resulting from frontal automobile crashes and to determine the effects of frontal airbags. The National Automotive Sampling System database files from 1993 to 2000 were examined in a study that included 25,464 individual cases that occurred in the United States. An analysis of the cases indicated that occupants exposed to an airbag deployment were statistically more likely to sustain a severe upper extremity injury (2.7%) than those occupants not exposed to an airbag deployment (1.6%) (P =.01). In particular, 0.7% of occupants exposed to an airbag deployment sustained a severe upper extremity injury specifically from the airbag. In addition, when in crashes with an airbag deployment, older occupants were at a higher risk for severe upper extremity injury, as well as occupants in crashes with higher changes in velocity.

Effect of airbag deployment on head injuries in severe passenger motor vehicle crashes in Ontario, Canada

BACKGROUND

The purpose of this study was to identify and analyze factors contributing to both airbag deployment and resulting head injuries (HIs) and to quantify the effect of airbag deployment on head injuries, in terms of odds of head injury and severity, in severe motor vehicle collisions (MVCs).

METHODS

Data were derived from severely injured (Injury Severity Score [ISS] > 12) drivers treated at Ontario's lead trauma hospitals (n = 1,272), and included all MVC driver deaths in the province (n = 665) from 1997-98. We conducted an epidemiologic description and a case-control study to compare drivers with and without HIs. Statistical analysis included Pearson's chi2, Wilcoxon rank-sum, and multiple logistic regression tests.

RESULTS

Seventy-one percent of drivers were men, peaking in the 25- to 34-year age group. The most common impact involved multiple vehicles (62%) approaching each other. Overall, 59% of crashes had a frontal location of impact. HIs were significantly associated with a lower age (median, 36 vs. 43 years), seat belt use (53% vs. 59%), and airbag deployment (7% vs. 10%), with higher ISS (median, 34 vs. 22), ejection (20% vs. 10%), and mortality rate (44% vs. 35%). Airbag deployment was associated with higher age and seat belt use, and lower ISS, ejection, and deaths. Importantly, there were fewer HIs with the deployment of an airbag (64% vs. 73%) and a lower severity of HI. When logistic regression was used to control for the effects of possible confounders, airbag deployment was not statistically associated with one's odds of HI (odds ratio, 0.827; 95% confidence interval, 0.560-1.220), but ISS, age, and ejection were.

CONCLUSION

Airbag deployment did not significantly lower a driver's odds of head injury in a severe MVC, but it did significantly lower the severity of head injury. This is a significant finding, given that 72% of our study population sustained a head injury and the importance of lowering the severity of these head injuries in terms of patients' ultimate outcome. The most important factor associated with head injuries was ejection, which nearly doubled a driver's odds of head injury (odds ratio, 1.759; 95% confidence interval, 1.201-2.577). This reinforces the supplementary protective effect of an airbag and that "buckling up" and keeping occupants in the vehicle is of primary importance in the prevention of head injuries.

Are seat belt restraints as effective in school age children as in adults? A prospective crash study

OBJECTIVE

To study effectiveness of seat belts for protecting school age children in road vehicle crashes.

DESIGN

Crash examinations by trained investigators.

SETTING

Ten Canadian university based crash investigation centres.

SUBJECTS

470 children aged 4-14 years, with 168 selected for detailed analysis, and 1301 adults.

MAIN OUTCOME MEASURES

Use of seat belts by vehicle occupants; severity of injury adjusted for age and crash severity.

RESULTS

Overall, 40% (189/470) of children were unbelted. Of the 335 children in cars driven by belted adults, 73 (22%) were unbelted. The odds of sustaining fatal or moderately severe injury (injury severity score > or =4) for children in the front passenger seat was more than nine times higher for unbelted children than for belted ones (odds ratio 9.8 (95% confidence interval 2.4 to 39.4)) and for those in the rear left seat was more than two times higher for unbelted than for belted children (2.6 (1.1 to 5.9)). The protection afforded by seat belts compared favourably with the results for adults in the same seat positions (odds ratios for unbelted v belted adults of 2.4 and 2.7 for front and rear seat passengers respectively).

CONCLUSIONS

Seat belts helped to protect school age children from injury in road vehicle crashes. However, 40% of children were unbelted. Despite standard seat belts being designed for adults, school age children were at least as well protected as adults.

Factors influencing the patterns of injuries and outcomes in car versus car crashes compared to sport utility, van, or pick-up truck versus car crashes: Crash Injury Research Engineering Network Study

BACKGROUND

Data using crash dummies suggest that motor vehicle crashes (MVCs) involving passenger sedans (S) vs sport utility, vans, or light trucks (SUVTs) produce more severe injuries than those involving two sedans (SvS). However, no detailed data regarding pattern of injuries or force mechanisms involved have been presented in real patients.

METHODS

The relationship of injury patterns and severities with MVC reconstruction data were obtained in 412 MVC patients, drivers or front seat passengers. Crashes were examined with regard to impact direction, frontal (F) or lateral (L) crashes, vehicle mass ratio, ISS, DELTA V, seat belt use, and airbag deployment (AB).

RESULTS

In 309 F-MVC, AB reduced overall ISS (24.3 to 17.9) with a reduction in the mean severity of traumatic brain injury (TBI) GCS < or = 12, from 48% to only 28%. This AB protection from TBI was preserved as DELTA V increased to > 30 mph even though non-AB protected body areas (thorax, lung, liver, and lower extremity injuries) all increased. When vehicles of incompatible size and mass (SUVT) had F-MVC with sedans the incidence of severe TBI rose as did face lacerations despite AB or belt use. In L-MVC between SUVT and sedans compared with SvS MVC, there was a cephalad shift in body injuries with increased thorax, but decreased lower extremity injuries. The incidence of TBI increased. Analysis of injury contact sites (hits) showed more hits and a wider distribution of contract sites in SUVT vs sedan MVC. These appeared due to the greater mass excess and larger mass ratio, hood height, and width in the F-SUVT vs S crashes. All of these factors plus the increased bumper height above the body frame side-door sill were injury causal factors in the L-SUVT vs S MVCs.

CONCLUSION

Both F and L crashes between sedans and SUVT with a high mass ratio shift the pattern of injury cephalad with increased thorax and intrathoracic organ injuries, and more severe TBI. These data suggest that improved head and thorax side-impact buffering and design features which transmit MVC forces from the higher front end of the larger mass SUVT to the frame of the sedan may better protect sedan occupants from side-impacts.

Correlation between crash severity, injury severity, and clinical course in car occupants with thoracic trauma: a technical and medical study

BACKGROUND

The crash mechanisms and clinical course of car occupants with thoracic injury were analyzed to determine prognostic factors and to create a basis for injury prophylaxis.

METHODS

A technical and medical investigation of car occupants with a thoracic injury (Abbreviated Injury Scale-thorax [AIS(THORAX)] > or = 1) at the scene of the crash and the primary admitting hospital was performed.

RESULTS

Between 1985 and 1998, 581 car occupants sustained a thoracic injury. Mean parameter values were as follows: AIS(THORAX), 2.5; Hannover Polytrauma Score (PTS), 21.4; Injury Severity Score (ISS), 24.2; Delta-v, 49.6 km/h (30.8 mph); and extent of passenger compartment deformation (DEF) (scale, 1--9), 4.0. In 19% (n = 112) of patients involved, the clinical course was evaluated: AIS(THORAX), 2.5; PTS, 20.0; ISS, 19.3; Delta-v, 50.1 km/h (31.1 mph); DEF, 3.9; intensive care unit time, 8.3 days; ventilation time, 5.7 days; and hospital stay, 15.3 days. In the groups with higher AIS(THORAX), ISS, PTS, and intensive care unit and ventilation time, higher Delta-v and DEF occurred. In patients with longer hospital stay, higher Delta-v, but no difference in DEF occurred.

CONCLUSION

The injury severity and the clinical course demonstrated a positive correlation with the crash severity. Therefore, our technical accident analysis allows prediction of the severity of injury and the clinical course. It may consequently serve as a tool for development of more sophisticated injury prevention strategies and may improve passive car safety.

Driver air bag effectiveness by severity of the crash

OBJECTIVES

This analysis provided effectiveness estimates of the driver-side air bag while controlling for severity of the crash and other potential confounders.

METHODS

Data were from the National Automotive Sampling System (1993-1996). Injury severity was described on the basis of the Abbreviated Injury Scale, Injury Severity Score, Functional Capacity Index, and survival. Ordinal, linear, and logistic multivariate regression methods were used.

RESULTS

Air bag deployment in frontal or near-frontal crashes decreases the probability of having severe and fatal injuries (e.g., Abbreviated Injury Scale score of 4-6), including those causing a long-lasting high degree of functional limitation. However, air bag deployment in low-severity crashes increases the probability that a driver (particularly a woman) will sustain injuries of Abbreviated Injury Scale level 1 to 3. Air bag deployment exerts a net injurious effect in low-severity crashes and a net protective effect in high-severity crashes. The level of crash severity at which air bags are protective is higher for female than for male drivers.

CONCLUSIONS

Air bag improvement should minimize the injuries induced by their deployment. One possibility is to raise their deployment level so that they deploy only in more severe crashes.

Fatal Airway Compromise Due to Retropharyngeal Hematoma after Airbag Deployment

In trauma patients it is possible for a hematoma to form in the potential space between the pharynx and cervical spine (the retropharyngeal space). Fewer than 30 cases of actual airway obstruction secondary to retropharyngeal hematomas have been reported. We present an unusual case of an elderly woman who was involved in a minor motor vehicle collision which deployed her airbag. She died as a result of anoxic injury to the brain. Autopsy results demonstrated transverse fractures through the bodies of C5 and C7 with associated significant retropharyngeal and mediastinal hematoma. Airbags have been shown to significantly decrease the mortality rate in frontal collisions; however, the potential for hyperextension injuries from airbag deployment exists, especially if the occupant is unrestrained, small, or sitting too close to the airbag. When this woman's airbag deployed, it most likely caused her vertebral fractures, hematoma, subsequent airway compromise, and anoxic brain injury. Whatever the mechanism of trauma, one must be cognizant of the potential risk for retropharyngeal hematoma and airway compromise when a patient presents with injury to the cervical spine.

Acute cervical spinal cord injury secondary to air bag deployment without proper use of lap or shoulder harnesses

The authors present a case report of a patient with cervical central spinal cord syndrome caused by a hyperextension injury after a motor vehicle collision in which the air bag deployed in the absence of shoulder or lap belt harnesses. The potential for cervical spine and spinal cord hyperextension injuries in passengers positioned in front of air bags without proper use of shoulder or lap belt harnesses is discussed. Cervical central spinal cord quadriplegia occurred with cervical spondylosis and kyphosis that was managed by early three-level cervical corpectomy in a 58-year-old patient. Early improvement in the patient's neurological status occurred but was incomplete at the time of this report. Cervical hyperextension injuries are possible in passengers positioned in the front seat of cars with air bags when shoulder or lap belt harnesses are not used properly. Previous biomechanical studies have documented the potential for these types of injuries.

On burn injuries related to airbag deployment

Airbags have been shown as a vital, supplemental restraining device that save lives and reduce morbidity associated with motor vehicles crashes. However, as with any developing technology, airbags have also been identified in some instances, as the source of injuries which, have been well described in the literature. To a significantly lesser degree, burns due to airbag deployment (about 7-8% of these injuries) have been reported. These injuries will be seen more frequently as more vehicles are equipped with airbags and should be suspected in drivers and passengers involved in accidents in which airbags have been activated. This article, reviews the various types of burns and their pathogenesis, found in crashes involving airbag deployments.

Air bag-associated injury to a child in the front passenger seat

We report the case of a 3.5-year-old front seat passenger who suffered significant head and neck injuries as a result of air bag deployment in a collision of <30 mph. These lesions included multiple abrasions of the lower half of the face, nose, forehead, and right ear, torn frenula, conjunctival petechiae, comminuted fractures of the left and right lateral frontal regions and right parietal bone, diastatic fracture of the coronal suture, subgaleal and subarachnoid hemorrhages, cortical contusions, subluxation of the atlantooccipital joint, and fracture of the C4 vertebral body. These lesions are consistent with trauma secondary to the deploying air bag and the head striking the interior of the car. The findings in this case further support the Centers for Disease Control and Prevention (CDC) guidelines of keeping children properly restrained, preferably in the back seat, or as far as possible from air bags.

Bilateral pneumothorax following air bag deployment

Air bags have been shown to decrease mortality from automobile accidents. Herein is a unique case of bilateral pneumothorax following deployment and rupture of an air bag with no other associated chest trauma. One may posit that rupture of the air bag allowed high-pressure gases to be expelled into the patient's lungs resulting in explosive barotrauma.

Patterns of injury associated with automobile airbag use

The wide use of automobile airbags has undoubtedly reduced the mortality and the incidence of serious injuries from motor vehicle accidents. However, automobile airbags appear to be associated with a variety of injuries including fatal injuries, ocular injuries, upper limb and chest injuries. Further improvements in airbag design together with education of the general public in their use should help reduce airbag-related injuries.

Airbags and children: a spectrum of C-spine injuries

Over 30 children who were improperly restrained or in rear facing safety seats have been reported killed in motor vehicle accidents (MVA) involving airbags. The authors report one minor and two major injuries in properly restrained children in the front passenger seat. In case 1, A 10-year-old seat-belted boy was involved in an MVA (40 km/h) with deployment of both airbags. Physical examination findings showed right hyphema with corneal abrasion, right cheek abrasion and minimal cervical tenderness. C-spine x-ray was normal. He was treated for whiplash and facial burns resulting from contact with hot gas released by the airbags and discharged. In case 2, a 4-year-old boy wearing a lapbelt was in a MVA (20 km/h) with airbag deployment. On arrival, his Glasgow coma score was 3 and he was hemodynamically unstable. Secondary survey after stabilization showed left neck abrasions and ecchymoses, quadraplegia, priapism, and absent rectal tone. C-spine x-ray showed atlanto-occipital dislocation with possible complete spinal cord transection at C1. Aggressive maneuvers were withheld, and the patient was pronounced dead. Autopsy findings confirmed the clinical diagnosis. In case 3, a 3-year-old boy in a forward-facing safety seat was in a MVA (60 km/h) with air bag deployment. The patient was fully awake. C-spine x-rays were normal. Because of fluctuating level of consciousness, he underwent head computed tomography (CT) scan, which demonstrated a posterior fossa subarachnoid hemorrhage and a hematoma posterior to the odontoid, suggesting a ligamentous tear. He remained asymptomatic and was discharged on day 6. A head CT scan at 1 month showed a periosteal reaction in the area of the alar ligament suggestive of partial ligamentous avulsion; this injury was the forerunner of atlanto-occipital dislocation. Airbags deploy by releasing a hot effluent at 300 km/h. Mechanisms of injury include direct contact of hot gas with facial skin and energy transmitted directly from the airbag system to the child's head and neck. These cases illustrate a spectrum of C-spine injuries caused by airbag deployment and support the recommendation that children under 12 years of age travelling in a car equipped with dual airbags be seated in the back.

Air bags: an update

Overwhelming evidence shows that air bags save lives and reduce morbidity associated with MVCs. The resulting benefits far outweigh the risks of air bag injury or death. Emergency nurses play a pivotal role in educating the public about active seat belt use in conjunction with passive restraint systems such as air bags. Air bags cannot be viewed as a single solution or panacea to occupant protection. Air bags are designed as supplemental devices to be used with seat belts and require the active participation of the user for maximum benefit and safety.

Experimentally induced upper facial third fractures in unembalmed human cadaver heads

Considerable need exists in the transportation industry to develop safety guidelines to protect the head and neck. One of the goals of this study was to produce facial fractures similar to those induced in motor vehicle crashes. Unembalmed cadaver heads were fixed to a supporting device and impacted with a steel pipe. The most common fracture was of the frontal sinus; multiple orbital wall, naso-orbitoethmoid, Le Fort I, II, and III fractures were also produced. Average impact speeds of 7.2 meters per second striking at the supraorbital rims created severe injury to both skull and contents. Energy absorption values accounted for the actual total contact time between head and pipe with tolerance level values measuring the force at specific intervals. The method described may be used to reproduce reliably those forces resulting in the facial fractures seen in the emergency room setting after motor vehicle crashes.

Air bag-related fatality in a short, forward-positioned driver

Air bag-related fatalities are rare. We report the case of a 17-year-old girl-4 feet, 11 inches tall-who sustained a fatal basilar skull fracture when her vehicle's air bag deployed during a lowspeed motor vehicle accident. This case emphasizes the need for seat belt use in air bag-equipped vehicles. Further study is needed to clarify the increased risk to shorter individuals and to those who drive with the seat in the far-forward position.

Airbag protection versus compartment intrusion effect determines the pattern of injuries in multiple trauma motor vehicle crashes

OBJECTIVE

A prospective study of the interaction between airbag (AB) and seat-belt (Bt) protection versus vehicular compartment (VC) intrusion effects on injury patterns in motor vehicle crash (MVC) trauma patients.

METHODS

Two hundred MVC patients, nonejected drivers or front seat passengers with multiple trauma or severe lower extremity (LE) trauma admitted to two Level I trauma centers.

RESULTS

In frontal crashes, airbags (AB) more than Bt reduced Glasgow Coma Scale severity in brain injury, face fracture, shock, and the need for MVC extrication (all p < 0.05). Frontal AB also had a protective effect on LE fractures (41% vs. 66%, p < 0.01), but had no significant protective effect on pelvic fractures. When AB protection was present, it prevented brain and face fracture injuries caused by impact contacts and reduced the incidence of these injuries resulting from VC intrusions (p < 0.05). Thoracoabdominal injuries resulting from steering wheel intrusion showed AB protection against intrusions of twice the magnitude of those seen in non-AB vehicles (p < 0.05). In frontal MVCs, AB reduced LE fracture contact injuries but did not prevent LE fractures resulting from intrusions of instrument panel, toepan, or floor pedal structures. In lateral MVCs, Bt did not protect against brain, face, thorax, or pelvic injuries.

CONCLUSIONS

Safety measures beyond frontal airbags must address frontal crash LE injuries induced by steering wheel, instrument panel, and toepan passenger compartment structure intrusions. Lateral crash injuries may profit from side AB supplemental restraint protection.