Cozen's Test is primarily used to assess lateral epicondylitis, commonly referred to as tennis elbow. During this test, the patient is asked to extend the wrist against resistance while their elbow is held in a flexed position. The central focus of the test is on the forearm extensors, specifically the wrist extensors, which are tested for pain and discomfort.
When the patient performs this test, the action of extending the wrist means that the forearm extensors are actively engaged and considered to be "shortening" as they contract to produce this motion. This contraction helps to evaluate the strength and condition of the muscle and its tendons, particularly in relation to the lateral epicondyle of the humerus.
In this context, the other options do not accurately describe the muscle action involved in Cozen's Test. The patient does not flex the wrist, stretch the forearm flexors, or extend the shoulder during this specific examination, making "shorten the forearm extensors" the precise action observed.