HISTORY: 14 year old right handed level 8 gymnast presents with complaints of progressive right greater than left elbow and forearm pain over the past four months. Despite bracing, activity modification and three months of physical therapy she still reported progressive worsening of pain and development of tingling in her hands and forearms. She notes she has a constant feeling of tightness over her anteromedial forearms and pain and tingling of her arm occurs the worst while writing in school or vaulting. Pain and numbness resolve with a few minutes of rest and elbow extension. She does not have any nighttime pain. PHYSICAL EXAMINATION: - Well appearing female adolescent - Full ROM of elbow, forearm, wrist and fingers - Sensation intact to light touch in the radial, medial and ulnar nerve distribution bilaterally - 5/5 strength in the radial, medial, ulnar, anterior interosseous and posterior interosseous nerves bilaterally - Mild TTP of proximal forearm and medial elbow bilaterally - Positive compression test at the proximal forearm - Positive Tinel’s test over the pronator teres - Positive Tinel’s test over cubital tunnel - Negative Tinel’s, Durkan’s and Phalen’s at the wrist bilaterally DIFFERENTIAL DIAGNOSIS: - Pronator syndrome - Cubital tunnel syndrome - Chronic exertional compartment syndrome of the forearm - Anterior interosseous nerve syndrome - Brachial plexus neuritis - Cervical radiculopathy TEST AND RESULTS: MRI elbow Left: MRI findings normal but noted presence of accessory anconeous epitrochlearis muscle. MRI elbow Right: Normal MRI. FINAL WORKING DIAGNOSIS: Pronator syndrome bilaterally. Left arm with accessory anconeous epitrochlearis muscle also causing ulnar neuropathy. TREATMENT AND OUTCOMES: Patient’s older sister previously had pronator syndrome as well as chronic exertional compartment syndrome for which she underwent median nerve release and fasciotomy. Patient and her parents elected to forgo compartment testing suspecting she also had both conditions. She underwent surgery on her left elbow with a median nerve release, ulnar nerve release and fasciotomy. She is due to have surgery on her right arm for median nerve release and fasciotomy three weeks after her left.