The use of a **helmet** by cyclists is essential to **significantly reduce the likelihood of suffering head injuries**. This is due to several reasons:

- **Impact protection**: The helmet protects the head from blows against the ground, other vehicles, or road elements. Additionally, it distributes the force of the impact across its entire surface, preventing it from concentrating in a single point and thus reducing the severity of injuries.

- **Prevention of serious injuries**: By preventing sharp objects from penetrating the head and protecting the face and head from burns when sliding on the ground, the helmet significantly decreases the risk of serious injuries.

- **Statistical evidence**: Head injuries are the leading cause of death in two-wheeled vehicle accidents. However, three out of ten people who have an accident on these vehicles save their lives thanks to the use of a helmet.

Therefore, although the helmet does not completely eliminate the risk of injuries, its use is crucial to significantly reduce them.