Airbags are designed to save lives during a collision, acting as a soft cushion to prevent the body from striking the vehicle’s hard interior surfaces. They have proven extremely effective. However, the sheer mechanical force and speed required for an airbag to deploy effectively introduces a secondary risk of injury, including the possibility of a concussion, also known as a mild traumatic brain injury (mTBI). Understanding the tension between the lifesaving function of the airbag and its potential to cause head trauma is important for anyone involved in a motor vehicle accident. This possibility of injury does not negate the overall safety benefit of the airbag.
Airbag Deployment: The Mechanism of Concussive Force
Airbags are engineered to deploy with extreme rapidity, inflating in less than one-twentieth of a second. This near-instantaneous inflation is necessary to cushion the occupant before they are thrown forward by crash forces. The speed of a deploying airbag can reach up to 200 miles per hour, creating a significant impact force.
A concussion occurs when the brain experiences a sudden jolt or blow that disrupts its normal function. This can happen in two primary ways related to airbag deployment. The first is a direct impact, where the occupant’s head strikes the rapidly expanding nylon bag with substantial force. This blunt-force trauma can cause the brain to collide with the inside of the skull.
The second mechanism, which is often more common, involves the rapid acceleration and deceleration of the head and neck. When the body is suddenly arrested by the seatbelt and the airbag, the head can be violently whipped forward and then backward. This violent back-and-forth motion forces the brain to move abruptly within the skull.
This rapid movement generates two types of forces on the brain tissue: linear acceleration (straight-line impact) and rotational acceleration (twisting motion). Rotational forces are particularly damaging as they cause shear stress, stretching and tearing the brain’s delicate nerve fibers. This type of injury can occur even if the head does not make direct contact with the deploying bag.
Identifying Concussion Symptoms Post-Accident
Recognizing the signs of a concussion after an accident is crucial because symptoms can be subtle or delayed. A concussion is a functional injury, meaning it impairs how the brain works, and is not always accompanied by loss of consciousness. Common physical symptoms include a persistent headache, dizziness, nausea or vomiting, and issues with balance.
Cognitive and emotional changes often appear alongside physical symptoms. Individuals may experience confusion, difficulty concentrating, or memory problems regarding the accident itself. They might also notice increased sensitivity to light or noise, or feel a general mental fogginess.
The onset of symptoms can be immediate, but it is common for them to develop hours or even days after the crash. This delayed presentation can lead people to underestimate the severity of their injury. Seeking prompt medical attention is the only way to properly diagnose a concussion and rule out more severe traumatic brain injuries.
Reducing Risk: Proper Seating Position and Safety
Proper seating position is the most effective way for occupants to minimize their risk of an airbag-related concussion. Since the airbag’s initial deployment zone is the most forceful, maximizing the distance between the occupant and the deployment panel is essential. Drivers should aim to sit with their breastbone at least 10 inches away from the center of the steering wheel.
The seatbelt is a complementary safety device that works with the airbag to protect the occupant. Always wearing a seatbelt correctly ensures the body remains properly positioned during the crash, preventing the person from being thrown too close to the deploying airbag. The seatbelt should fit snugly across the lap and chest.
Children under 13 years of age should always ride in the back seat, as the force of a frontal airbag deployment is calibrated for adults. Passengers should also ensure their seat is positioned as far back as possible from the dashboard. Maintaining an upright posture with the back against the seat prevents the occupant from being “out of position” when the crash occurs.