Lab 1—Superficial Back Skeletal—Questions 1 of 1 1

Home , Long thoracic nerve, Lumbar triangle, Rhomboid muscles, Serratus anterior muscle, Splenius capitis muscle, Suprascapular nerve

Lab 1—Superficial Back Skeletal—Questions 1 of 1 1. The spine of the scapula is generally in level with the spinous process of the

A. Second thoracic vertebra B. Seventh cervical vertebra C. Third thoracic vertebra D. Fourth thoracic vertebra E. Sixth cervical vertebra

1 Lab 1—Superficial Back Skeletal—Answers 1. Answer C. (2)The spine of the scapula is generally in level with the spinous process of the third thoracic (T3) vertebra. Sixth and seventh cervicals (C6 and C7), and second thoracic (T2) are above, while fourth thoracic (T4) is below the scapular spine.

2 Lab 1—Superficial Back Muscles; Tendons — Questions 1 of 3 1. A college baseball pitcher has shoulder discomfort, and 5. A 27-year-old man is brought to the emergency room you suspect a rotator cuff tear. You will most likely see after sustaining a knife wound in the back. His vital signs damage to the tendon of which of the following muscles? are within normal limits. On exam, you appreciate a 4 cm long laceration that runs parallel to the inferior medial bor- A. Supraspinatus der of the scapula, and is 2cm from the spinous process B. Infraspinatus of T5. The laceration has visibly penetrated at least 1 cm C. Subscapularis into the muscle tissue. Which muscle is most likely affect- D. Teres major ed? E. Teres minor A. Deltoid B. Infraspinatus C. Levator scapulae D. Rhomboid major E. Triceps brachii

2. Which muscle listed below is the main abductor of the 6. A 38-year-old woman with a long history of shoulder humerus and can become impinged if the humerus is in pain is admitted to a hospital for surgery. Which of the internal rotation? following muscles becomes ischemic soon after ligation of the superficial or ascending branch of the transverse cer- A. Teres minor vical artery? B. Latissimus dorsi C. Biceps brachii A. Latissimus dorsi D. Supraspinatus B. Multifi dus E. Subscapularis C. Trapezius D. Rhomboid major E. Longissimus capitis

3. As a powerful shoulder extensor, which muscle is a 7. While playing squash, a young woman tore one of her major muscle used in swimming? right rotator cuff muscles. Which of the following is most A. Teres minor likely to have been injured? B. Latissimus dorsi C. Biceps brachii A. Infraspinatus D. Supraspinatus B. Subscapularis E. Subscapularis C. Supraspinatus D. Teres major E. Teres minor

4. As a powerful shoulder extensor, which muscle is a 8. A 19-year-old woman has a painful right shoulder one day major muscle used in swimming? after playing basketball. She fell twice during the game, each A. Teres minor time using the right upper limb to protect the body against im- B. Latissimus dorsi pact with the floor. The right shoulder is not obviously deformed but there is tenderness between the acromion of the scapula C. Biceps brachii and the greater tuberosity of the humerus. Abduction of the arm D. Supraspinatus from the anatomic position against resistance is painful. Alt- E. Subscapularis hough the patient can actively abduct the right arm from 0 to 60° and from 120 to 180°, pain accompanies active and passive abduction from 60 to 120°. Which of the following injuries is MOST likely given the history and physical exam? A. shoulder joint dislocation B. tear of the deltoid muscle C. fracture of the clavicle D. incomplete tear of the supraspinatus tendon E. complete tear of the supraspinatus tendon

3 Lab 1—Superficial Back Muscles; Tendons — Answers 1. Answer A. (11) The tendon of the supraspinatus is 5. Answer D (3) The insertion of the rhomboid major typically damaged in a rotator cuff tear due to the narrow (D) is the medial border of the scapula (it arises from the space between the head of the humerus and the acromi- spinous processes of T2 to T5, as well as the suprasp- on. inous ligament). The deltoid (A) originates at the spine of the scapula and goes laterally to insert on the humerus. The infraspinatus (B) originates at the posterior scapula and goes laterally to form part of the rotator cuff (remember: SITS). The levator scapulae (C) inserts at the superior medial border of the scapula and goes superior- ly. The triceps brachii (E) originates at the lateral scapula and inserts on the humerus.

2. Answer D. (2) The supraspinatus also inserts on 6. Answer C. (1) The trapezius receives blood from the greater tubercle, but the muscle passes under the the superficial branch of the transverse cervical artery. acromion process. Following this path, the supraspinatus The latissimus dorsi receives blood from the thoracodor- abducts the arm. In internal rotation, the muscle can be sal artery. The rhomboid major receives blood from the impinged between the acromion and coracoid processes. deep or descending branch of the transverse cervical artery. The multifi dus and longissimus capitis receive blood from the segmental arteries.

3. Answer B. (2) Swimming requires activation of the 7. Answer C. (3) The supraspinatus is the most com- muscles of both shoulder extension and internal rotation monly injured rotator cuff muscle. The infraspinatus, teres of the humerus. Minor activation of the deltoids and teres minor, and subscapularis are the other rotator cuff mus- major assist the latissimus dorsi - the major muscle of cles; they could also be torn, but are torn less frequently. freestyle swimming. The teres major is not part of the rotator cuff.

4. Answer B. (2) Swimming requires activation of the 8. Answer D. (2) Painful arm abduction that extends in muscles of both shoulder extension and internal rotation an arc from about 60 to 120° suggests a lesion of the su- of the humerus. Minor activation of the deltoids and teres praspinatus tendon of insertion or inflammation of the major assist the latissimus dorsi - the major muscle of subacromial bursa. The history, presence of tenderness freestyle swimming. between the acromion and greater tuberosity, and pain upon abduction of the arm from the anatomic position against resistance, all suggest an incomplete rupture of the supraspinatus tendon.

4 Lab 1—Superficial Back Muscles; Tendons — Questions 2 of 3 9. A 21-year-old woman walks in with a shoulder and arm 12. After a 26-year-old man’s car was broadsided by a injury after falling during horseback riding. Examination large truck, he is brought to the emergency department indicates that she cannot adduct her arm because of pa- with multiple fractures of the transverse processes of the ralysis of which of the following muscles? cervical and upper thoracic vertebrae. Which of the following muscles might be affected? A. Teres minor B. Supraspinatus A. Trapezius C. Latissimus dorsi B. Levator scapulae D. Infraspinatus C. Rhomboid major E. Serratus anterior D. Serratus posterior superior E. Rectus capitis posterior major

10. An 11-year-old boy falls down the stairs. A physician 13. A 34-year-old woman crashes into a tree during a ski- examines a radiograph of the boy’s shoulder region (see ing lesson and is brought to a hospital with multiple inju- figure below). If the structure indicated by the letter A is ries that impinge the dorsal primary rami of several spinal calcified, which of the following muscles is most likely par- nerves. Such lesions could affect which of the following alyzed? muscles? A. Deltoid B. Teres major A. Rhomboid major C. Teres minor B. Levator scapulae D. Infraspinatus C. Serratus posterior superior E. Subscapularis D. Iliocostalis E. Latissimus dorsi

10. 14. During a domestic dispute, a 16-year-old boy receives a deep stab wound around the superior angle of the scapula near the medial border, which injures both the dorsal scapular and spinal accessory nerves. Such an injury could result in paralysis or weakness of which of the following muscles?

A. Trapezius and serratus posterior superior B. Rhomboid major and trapezius C. Rhomboid minor and latissimus dorsi D. Splenius cervicis and sternocleidomastoid E. Levator scapulae and erector spinae

11. Mrs. Jones was riding in the front seat of her son's 15. After an automobile accident, a back muscle that van when the vehicle abruptly stopped. Unfortunately, she forms the boundaries of the triangle of auscultation and was not wearing her seatbelt and was thrown forward and the lumbar triangle receives no blood. Which of the follow- as a result of the accident, the transverse processes of ing muscles might be ischemic? her cervical vertebrae are crushed against the dashboard of the van. Which of the following muscles might be para- A. Levator scapulae lyzed? B. Rhomboid minor C. Latissimus dorsi A. Trapezius D. Trapezius B. Latissimus dorsi E. Splenius capitis C. Rhomboid major D. Levator scapulae E. Serratus posterior superior

5 Lab 1—Superficial Back Muscles; Tendons — Answers 9. Answer C. (1) The latissimus dorsi adducts the 12. Answer B. (1) The levator scapulae arise from the arm, and the supraspinatus muscle abducts the arm. The transverse processes of the upper cervical vertebrae and infraspinatus and the teres minor rotate the arm laterally. inserts on the medial border of the scapula. The other The serratus anterior rotates the glenoid cavity of the muscles are attached to the spinous processes of the ver- scapula upward, abducts the arm, and elevates it above a tebrae. horizontal position

10. Answer D. (1) The scapular notch transmits the 13. Answer D. (1) The dorsal primary rami of the spi- suprascapular nerve below the superior transverse liga- nal nerves innervate the deep muscles of the back, in- ment, whereas the suprascapular artery and vein run over cluding the iliocostalis. The other muscles are the superfi- the ligament. The suprascapular nerve supplies the su- cial muscles of the back, which are innervated by the ven- praspinatus and infraspinatus muscles. The axillary nerve tral primary rami of the spinal nerves. innervates the deltoid and teres minor muscles. The subscapular nerves innervate the teres major and subscapularis muscles.

14. Answer B. (1) The dorsal scapular nerve innervates the levator scapulae and rhomboid muscles, whereas the accessory nerve innervates the trapezius and sternocleidomastoid muscles. The serratus posterior superior is innervated by ventral primary rami of the spinal nerves, whereas the splenius cervicis and erector spinae are innervated by dorsal primary rami of the spinal nerves.

11. Answer D. (5)The levator scapulae is attached to 15. Answer C. (1) The latissimus dorsi forms bounda- the transverse processes of the upper cervical vertebrae. ries of the auscultation and lumbar triangles and receives All the other muscles are attached to the spinous pro- blood from the thoracodorsal artery. The levator scapulae, cesses. rhomboid minor, and splenius capitis muscles do not form boundaries of these two triangles. The trapezius muscle forms a boundary of the auscultation triangle but not the lumbar triangle. The levator scapulae, rhomboid minor, and trapezius muscles receive blood from the transverse cervical artery. The splenius capitis muscle receives blood from the occipital and transverse cervical arteries.

6 Lab 1—Superficial Back Muscles; Tendons — Questions 3 of 3 16. A 29-year-old male presents to his primary care physician with the chief complaint of right shoulder pain. He pitch- es in a local baseball league. While pitching in his last game 2 weeks ago, he experienced severe pain in his left shoulder. He tried icing the shoulder and taking ibuprofen, but says that he still experiences pain with motion. On physical examination, he is unable to actively abduct his right arm above his head, but he has full passive range of motion. Which of the following muscles is most likely injured in this patient? A. lnfraspinatus B. Subscapularis C. Supraspinatus D. Teres Major E. Teres Minor

17. A 60-year old female presents to the emergency room with a history of falling on her right elbow. She cannot raise her right arm. Physical exam reveals loss of sensa- tion over the lateral side of the right arm. Radiology reveals fracture of surgical neck of humerus. Which of the following muscles are supplied by the nerve that is most likely damaged? A. Infraspinatus B. Teres minor C. Subscapularis D. Supraspinatus E. Teres major

7 Lab 1—Superficial Back Muscles; Tendons — Answers 16. Answer C. This patient presents with signs and symptoms suspicious for a rotator cuff injury. He has decreased active range of motion but normal passive range of motion. The rotator cuff is comprised of four muscles, the supraspinatus, subscapularis, infraspinatus, and teres minor. A rotator cuff injury includes any type of irritation or damage to the rotator cuff muscles or tendons. Of these four muscles, the supraspinatus is most frequently torn as it passes below the acromion. The tear usually occurs at the point of insertion onto the humeral head at the greater tubercle.

17. Answer B. Fracture of the surgical neck of the humerus occurs commonly and damages the axillary nerve. The axillary nerve innervates the deltoid and teres minor muscles and gives rise to the lateral brachial cutaneous nerve, which carries the sen- sation from the lateral side of the arm. Axillary nerve arises from the posterior cord of brachial plexus. It has a root value of C5 – C6. It passes posteriorly through the quadrangular space accom- panied by the posterior circumflex humeral artery and winds around the surgical neck of the humerus. Deltoid is a powerful muscle that arises from lateral third of clavicle and scapula, and is inserted on the deltoid tuberosity. It covers the shoulder joint like a cape. It is the main abductor of the arm. Patient could not raise the arm because of paralysis of deltoid muscle. The teres minor muscle stabilizes the shoulder joint, and forms rotator cuff along with supraspinatus, infraspinatus, and subscapularis muscles. It rotates arm laterally.

8 Lab 1—Superficial Back Nerves—Questions 1 of 1 1. A 47-year-old woman has had a lumpectomy and axillary dissection to check for metastasis. She has come in for her follow-up appointment and her physician notices on her physical examination that the medial part of her scapula protrudes from her back and that she is not able to raise her arm above the horizontal level. Which of the following nerves has been damaged during her surgery?

A. Median nerve B. Ulnar nerve C. Thoracodorsal nerve D. Long thoracic nerve E. Radial nerve

2. A 32-year-old male weight lifter comes to the Primary Care Physi- cian with a 24-hour history of his left scapula is pulling out of the chest wall when he raises his arm. He also has pain in his left shoulder which began a few weeks ago, though he did not notice any abnormalities in his back at that time. He associates the pain with the use of a new machine at the gym, where he lifts 100 pounds with his arms over his head, several times. The past medical history is irrelevant. On physical exam (PE), the patient has pain and diffi- culty in raising his left arm. The scapular stabilization test decreases the pain and allows the patient to raise his left arm. The rest of the PE is normal. These findings are suggestive of what injury? A. Axillary nerve injury B. Dorsal scapular nerve injury C. Long thoracic nerve injury D. Suprascapular nerve injury E. Upper subscapular nerve injury

3. A 26-year-old man is stabbed in the left chest during a bar brawl. Several days after he is treated, he returns to the physician complaining of decreased function in his left arm. Physical examination reveals a winged left scapula and an inability to raise his left arm above the horizontal. Which of the following nerves is most likely affected? A. Axillary B. Long thoracic C. Lower subscapular D. Suprascapular E. Thoracodorsal

9 Lab 1—Superficial Back Nerves—Answers 1. Answer D. (5) The long thoracic nerve innervates the serratus anterior muscle. Paralysis of this muscle causes a "winged scapula," in which the vertebral or medial border and inferior angle of the scapula protrudes away from the thorax. Other nerves do not supply the serratus anterior muscle.

2. Answer C. (2) Long thoracic nerve (C5, C6, C7) is the correct answer. This nerve innerves the serratus anterior muscle, which has the function of attaching the scapula to the chest wall. The typical sign of injury of this nerve is the winged scapula. To evaluate it, a scapular stabilization test has to be done. This test consists of sta- bilizing the scapula manually keeping it against the chest wall; the pain decreases and the patient can raise his arm higher.

3. Answer B. (4) The serratus anterior, innervated by the long thoracic nerve, is responsible for stabilization of the scapula during abduction of the arm from 90 to 180 degrees. When the long thoracic nerve is damaged, it is difficult to elevate the arm above the horizontal. This nerve arises from C5, C6, and C7. Remember: a "winged scapula" is a classic clue for long thoracic nerve injury.