The **seat belt** is a crucial element for the protection of vehicle occupants in the event of an accident. For it to be effective, it must be **properly adjusted to the body**. This means it should not be too loose or too tight, allowing for comfortable yet secure movement.

A poorly adjusted belt can cause the **submarine effect**, which occurs when the body slides down and under the belt during an accident. This effect is dangerous and can increase the risk of injury. To avoid it, it is essential that the belt is correctly adjusted and that the seat is not too reclined backward.


Additionally, the **shoulder strap** of the belt should pass over the collarbone, between the shoulder and neck, and go down the center of the chest. The **lap belt** should be placed over the hip bones, always below the stomach, to prevent internal injuries in the event of an accident.


Therefore, to maximize safety and avoid the submarine effect, it is essential that the seat belt is well adjusted to the body.