Final answer:
In identifying extremes in range of motion for a header, it's important to focus on neck flexibility and extension, head rotation, and spinal alignment. These factors help in executing an effective header and minimizing injury risk.
Step-by-step explanation:
When identifying extremes in range of motion for a header in sports, particularly in soccer, there are several key areas to pay attention to. These include the flexibility and extension of the neck muscles, the ability to rotate the head for optimal ball contact, and the overall spinal alignment during the motion. Ensuring these areas have a healthy range of motion is crucial to perform a header effectively and to minimize the risk of injury.