Which muscle would you primarily target to improve neck extension?

The splenius capitis is the primary muscle targeted for improving neck extension because it is directly responsible for this movement. This muscle runs from the upper thoracic vertebrae and the nuchal ligament up to the mastoid process of the skull and the occipital bone. When the splenius capitis contracts, it pulls the head backward and helps to extend the neck. Additionally, it plays a role in rotating and laterally flexing the head, but its primary action is neck extension.

In contrast, the rectus abdominis, external abdominal oblique, and serratus anterior do not contribute significantly to neck extension. The rectus abdominis is primarily involved in flexing the lumbar spine and stabilizing the pelvis. The external abdominal oblique assists with trunk rotation and lateral flexion rather than actions involving the cervical spine. The serratus anterior primarily functions in the protraction and stabilization of the scapula, which has no direct role in neck extension. Therefore, focusing on the splenius capitis would be the most effective approach for enhancing neck extension.