An oblique fracture is characterized by what mechanism of injury?

An oblique fracture is indeed characterized by sudden torsion on a fixed bone. This type of fracture occurs when a rotational force is applied to a bone that is unable to move freely. The application of this twisting force leads to a fracture that runs diagonally across the bone, rather than straight across or along the length of it.

In contrast to this mechanism of injury, a direct blow while the bone is stable might lead to transverse fractures or other fracture types, as the force would focus on a single point rather than producing the torsional effect needed for an oblique fracture. Repetitive stress without impact could result in stress fractures, which typically occur due to cumulative loading rather than a sudden twisting motion. Lastly, a vertical impact often leads to compression fractures rather than oblique fractures, as the forces act along the line of the bone rather than creating a twisting motion. Understanding the mechanism of injury is key in distinguishing between different types of fractures in athletic training and injury management.