What is the primary action involved in the active lateral epicondylitis test?

The primary action involved in the active lateral epicondylitis test is for the patient to actively extend the wrist against resistance. This movement is significant because it helps to evaluate the function of the extensor muscles and tendons, particularly the extensor carpi radialis brevis, which is commonly associated with lateral epicondylitis, often referred to as "tennis elbow."

When the patient extends the wrist while resisting movement, it places stress on the affected structures, potentially eliciting pain if lateral epicondylitis is present. This test aims to mimic the activities that could exacerbate the condition, making it an effective way to assess for injury in this area.

The other options present movements that do not effectively target the specific actions needed to evaluate for lateral epicondylitis, as they do not place the relevant extensor muscles and tendons under the same level of stress associated with the condition.