Which action reproduces pain in lateral epicondylitis?

In lateral epicondylitis, also known as tennis elbow, the primary issue lies with the extensor tendons of the forearm, particularly the extensor carpi radialis brevis. This condition is characterized by pain on the outer elbow, which is often aggravated by specific movements that involve these muscles.

Resisted wrist extension with full elbow extension effectively reproduces the pain experienced in lateral epicondylitis because this action requires the extensor muscles to contract against resistance, putting strain on the already irritated tendons. When the elbow is fully extended, it places the extensor tendons in a position where they are under maximum tension, thus provoking pain if lateral epicondylitis is present.

Other movements, while they may involve the wrist, do not specifically target the affected muscles in the same way. For instance, resisted wrist flexion focuses on the flexor tendons, and passive wrist movements may not adequately engage the extensor muscles or achieve the same level of strain. Hence, the action that most directly reproduces pain in lateral epicondylitis is the resisted wrist extension with the elbow fully extended.