Understanding the Three Collisions in a Crash

The Forces at Play in a Car Crash

Every car accident is governed by Newton's laws of physics, particularly the First Law of Motion: an object in motion stays in motion unless acted upon by an external force. When a car is traveling down the road, it carries kinetic energy, a form of energy that is proportional to both its mass and speed. The faster a vehicle moves and the heavier it is, the more kinetic energy it carries.

When a car crashes, this energy has to go somewhere. That’s where crumple zones, airbags, and seatbelts come into play, working to absorb and redirect the force of the crash. However, while the car may slow or stop almost instantly, the human body inside continues moving at the vehicle’s pre-crash speed, leading to further collisions—both external and internal. Understanding these forces provides critical insight into why injuries occur, even in crashes that might not appear severe at first glance.

The First Collision: Vehicle Impact

The initial collision in a motor vehicle crash, often referred to as the vehicle collision, is the most visible moment. It’s the moment when the car strikes another object—whether that’s another vehicle, a tree, or a barrier. At this point, the car rapidly decelerates, and much of the force of the collision is absorbed by the vehicle’s crumple zones. These are specially designed areas in the front and rear of modern cars that collapse on impact, helping to reduce the force that reaches the occupants inside.

However, even with these advanced safety features, and depending on the point of impact, this can lead to different outcomes for the vehicle and those inside. The vehicle's kinetic energy transfers to the occupants and everything inside. The car may stop moving, but for the people inside, the crash has only just begun. Safety features like crumple zones are critical in preventing some of the energy from reaching the occupants, but they can’t eliminate the force entirely.

Injuries that occur in this first collision often involve blunt trauma from the deceleration. Common injuries include concussions, head trauma from hitting the steering wheel or dashboard, and fractures resulting from the sudden jolt of the crash. The first collision is the trigger for what comes next—the far more dangerous impacts involving the human body itself.

The Second Collision: Human Impact

While the vehicle may have come to a stop, the people inside it are still moving at the same speed the car was traveling before the crash. This is where the second collision comes into play: the human collision. In this moment, the passengers collide with the vehicle’s interior—whether it’s the steering wheel, dashboard, windshield, or even the seatbelt.

Seat belts and airbags are vital in mitigating the damage of this collision. Still, even with these safety measures, injuries from the secondary collision can be serious. Whiplash is a common result of the body being thrown forward and then rapidly snapped back. Injuries to the face, collarbone, and lower extremities are also typical, especially in high-speed collisions. In cases where the seatbelt isn’t worn, the human collision can be devastating, often resulting in occupants being thrown from the vehicle.

The Third Collision: Internal Impact

The third and final collision is one that’s often overlooked because it happens inside the body. Known as the internal collision, this impact occurs when the internal organs—such as the brain, heart, or lungs—continue moving even after the body has come to a stop. Just as the body is propelled forward during the second collision, the organs inside the body move in the same way, often striking the skeletal structure or other organs.

For instance, the brain may collide with the inside of the skull, causing a concussion or more severe brain injuries. The heart and lungs may be forced against the ribcage, leading to bruising or internal bleeding. Similarly, organs like the liver and spleen may tear or rupture from the force of the impact. These injuries can be life-threatening and may not always show immediate symptoms, which is why seeking medical attention after any crash is crucial—even if you feel fine.

What Are Some Common Injuries from Car Collisions?

Each of the three types of collisions—vehicle, human, and internal—can lead to different types of injuries, depending on the forces involved and the safety features in place. While modern cars are equipped with various systems to mitigate injury, many crashes still result in significant trauma to the body. Below are some of the most common car crash injuries and how they relate to each type of collision.

• Head and neck injuries: Whiplash is one of the most common injuries in car accidents, resulting from the rapid back-and-forth motion of the neck during the human collision. Concussions and more severe brain injuries can occur during both the human and internal collisions, particularly when the head strikes the steering wheel or the brain is jolted inside the skull
• Spinal injuries: The force of the crash often compresses or twists the spine, leading to herniated discs or, in severe cases, fractures. Spinal cord injuries can result in long-term disability, making it one of the more catastrophic outcomes of car accidents
• Internal bleeding and organ damage: Internal injuries are often the most dangerous because they are less obvious and can go undetected immediately after the crash. Common examples include bruising or tearing of the liver, spleen, and lungs, as well as internal bleeding that may become life-threatening without prompt treatment

The effects of internal collisions, especially, are dangerous because they often remain hidden until they worsen. Internal bleeding, organ damage, and brain injuries may not present themselves right away, but if left untreated, they can become fatal. This is why post-accident medical evaluations are essential, regardless of how minor the crash may seem.

What safety precautions can minimize these injuries?

While car accidents are unpredictable, drivers and passengers can take several steps to reduce the risk of serious injury. Modern safety features, along with responsible driving habits, can significantly mitigate the forces involved in the three collisions. Below are some essential safety precautions to keep in mind.

• Always wear a seatbelt: Seat belts are one of the most effective ways to prevent serious injury in a crash. They work by restraining the body during the human collision, preventing it from continuing its forward motion and distributing the energy of the impact across stronger areas, such as the pelvis and chest. This reduces the risk of being thrown into the dashboard or windshield, significantly lowering the chances of severe injury
• Utilize airbags: Airbags complement seatbelts by providing a cushion for the head and chest, particularly during frontal collisions. They slow the forward motion of the upper body, reducing the force of the impact and helping to prevent serious head and chest injuries. To maximize their effectiveness, it’s important to sit in a proper position—sitting too close to the airbag or leaning against the window can reduce its protective benefits
• Avoid loose objects in the vehicle: Even small items like cell phones or water bottles can become dangerous projectiles during a crash, contributing to the human collision. Store heavier objects in the trunk and keep the cabin free of clutter to minimize the risk of additional injury
• Child safety seats: For children, proper car seats are essential. These seats are specifically designed to hold children securely during a crash, reducing the risk of injury from both the human and internal collisions. Ensure the car seat is age-appropriate and properly installed

By understanding and using these safety features correctly, drivers and passengers can significantly reduce their chances of sustaining serious injuries, even in a high-impact crash.

Key Takeaways

Understanding the three collisions that occur in every car crash—the vehicle, human, and internal collisions—provides crucial insight into the forces that cause injuries and how safety features can mitigate these effects. While modern vehicles are equipped to reduce some of the impact, the risk of injury is always present. By being aware of the dangers and taking necessary precautions, you can better protect yourself and those around you.

At YourAccident.com, we make finding the right car accident lawyer simple, ensuring you’re supported by experts who specialize in personal injury claims. Whether you’re dealing with minor injuries or more complex legal issues, our network of attorneys is here to help you through every step of the claims process. Reach out today for a free consultation and take the first step toward securing your financial recovery.