A 16-year-old girl comes to the office due to several months of left elbow pain. The pain is worse with activity and limits her exercise. She has attempted treatment with over-the-counter ibuprofen and acetaminophen but has had only partial relief. Medical history is notable for seasonal allergies, and current medications include a fluticasone nasal spray. Further evaluation shows that the patient's condition is due to a tendon injury. A long-acting glucocorticoid injection is administered at the most tender spot, as marked in the image below. Which of the following actions is most likely performed by the affected muscle?

Question

A 16-year-old girl comes to the office due to several months of left elbow pain.  The pain is worse with activity and limits her exercise.  She has attempted treatment with over-the-counter ibuprofen and acetaminophen but has had only partial relief.  Medical history is notable for seasonal allergies, and current medications include a fluticasone nasal spray.  Further evaluation shows that the patient's condition is due to a tendon injury.  A long-acting glucocorticoid injection is administered at the most tender spot, as marked in the image below.  Which of the following actions is most likely performed by the affected muscle?

Quizplus · Accepted Answer

11ec160b_35e8_99aa_9249_cd79ec0cdbba_MD0001_00 This patient has pain over the lateral epicondyle of the humerus, suggesting lateral epicondylitis (ie, tennis elbow). Lateral epicondylitis is classically seen in tennis players due to repetitive wrist extension (backhand strikes) transmitting sudden, extreme forces through the lateral epicondyle. The lateral epicondyle serves as the primary attachment point for extensor carpi radialis brevis and extensor digitorum, which are the primary muscles involved in wrist extension. Overuse of these muscles can cause repetitive microtrauma of the tendons at their origins on the lateral epicondyle, leading to angiofibroblastic tendinosis (ie, excess fibroblasts and neovascularization) without a significant inflammatory infiltrate. This results in swelling and pain over the lateral epicondyle and proximal extensor tendons. Overuse of the wrist flexor muscles can cause medial epicondylitis (ie, golfer's elbow), which occurs by a similar process in the tendons of the flexor muscles near their attachment on the medial epicondyle (Choice F). (Choice A) Adduction of the fingers is primarily accomplished by the palmar interosseous muscles, which originate on the metacarpals. (Choice B) Flexion of the forearm is primarily accomplished by the biceps brachii, brachialis, and brachioradialis muscles. None of these muscles originate on the lateral epicondyle. (Choice C) Shoulder abduction is primarily accomplished by the supraspinatus and deltoid muscles. Overuse of the supraspinatus leads to supraspinatus tendinopathy (ie, rotator cuff tendinopathy). (Choice D) Overuse of the abductor pollicis longus (thumb abduction) and extensor pollicis brevis (thumb extension) can result in de Quervain tendinopathy, which causes thumb and wrist pain. Educational objective: Lateral epicondylitis (ie, tennis elbow) is characterized by overuse of wrist extensor muscles (eg, extensor carpi radialis, extensor digitorum), leading to angiofibroblastic tendinosis at their attachment on the lateral epicondyle. __________ References: Lateral epicondylitis of the elbow. (http://www.ncbi.nlm.nih.gov/pubmed/23398951)

A 16-Year-Old Girl Comes to the Office Due to Several