What is the diagnosis for tenderness at the medial epicondyle that worsens with pulling activities and wrist flexion against resistance?

The diagnosis of tenderness at the medial epicondyle that worsens with pulling activities and wrist flexion against resistance indicates medial epicondylitis, commonly known as golfer's elbow. This condition is characterized by the inflammation of the tendons that attach to the medial epicondyle, where the forearm flexor muscles originate. Activities that involve repetitive wrist flexion or gripping can irritate and inflame these tendons, leading to pain and tenderness in that area.

Patients often report pain that increases with specific movements, such as flexing the wrist or performing tasks that require pulling or gripping. This specific combination of symptoms—tenderness over the medial epicondyle, worsening pain with wrist flexion or pulling motions—confirms the diagnosis.

The other conditions listed do not present with this exact location of pain or symptom pattern. For instance, patellar tendinopathy primarily affects the knee, while tendinitis of the biceps typically involves pain over the anterior shoulder or upper arm. A rotator cuff injury would usually present with shoulder pain and limitations in shoulder mobility, rather than pain localized to the elbow. Hence, the details provided strongly support the diagnosis of medial epicondylitis.