Arm Muscles Quiz
Questions: 16 · 10 minutes
1. An injury to the musculocutaneous nerve would most directly weaken which combination of movements?
Elbow extension and wrist extension
Elbow flexion and forearm supination
Wrist flexion and finger abduction
Shoulder abduction and lateral rotation
2. A climber has pain near the medial epicondyle when forcefully flexing the wrist. Which attachment is most likely being stressed?
Common flexor tendon
Triceps brachii tendon
Common extensor tendon
Distal biceps tendon
3. A tendon can be felt running through the intertubercular groove of the humerus. Which muscle does this tendon belong to?
Short head of biceps brachii
Long head of biceps brachii
Long head of triceps brachii
Coracobrachialis
4. Which nerve supplies all three heads of the triceps brachii?
Musculocutaneous nerve
Radial nerve
Median nerve
Axillary nerve
5. Which muscle extends the thumb at its interphalangeal joint?
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Flexor pollicis longus
6. While pushing open a heavy door, a person forcefully straightens the elbow. Which muscle is the main agonist for this action?
Biceps brachii
Brachialis
Triceps brachii
Pronator teres
7. Compression of the posterior interosseous nerve would most characteristically produce which finding?
Weak finger extension without a cutaneous sensory deficit
Weak elbow flexion with numbness of the lateral forearm
Weak finger abduction with numbness of the little finger
Loss of thumb opposition with numbness of the index finger
8. A person develops wrist drop after an injury to the radial nerve in the arm. Weakness of which muscle group most directly explains the dropped wrist?
Wrist flexors
Wrist extensors
Forearm pronators
Thenar muscles
9. Following an ulnar nerve injury at the elbow, a person has difficulty spreading the fingers apart and bringing them together. Which muscles are primarily affected?
Extensor indicis and extensor digiti minimi
Flexor digitorum superficialis and profundus
Dorsal and palmar interossei
Abductor pollicis longus and extensor pollicis brevis
10. Where does the biceps brachii insert?
Radial tuberosity
Coronoid process of the ulna
Olecranon of the ulna
Lateral epicondyle of the humerus
11. Which movement is produced most directly by pronator quadratus?
Forearm supination
Wrist abduction
Elbow extension
Forearm pronation
12. Which rotator-cuff muscle is chiefly responsible for initiating the first part of shoulder abduction?
Subscapularis
Infraspinatus
Teres minor
Supraspinatus
13. A patient can flex the proximal interphalangeal joint of an index finger but cannot flex its distal interphalangeal joint. Which muscle is most likely impaired?
Flexor digitorum superficialis
Extensor digitorum
Flexor digitorum profundus
Palmar interosseous
14. Median nerve compression in the carpal tunnel can make it difficult to place the thumb pad against the little-finger pad. Weakness of which muscle most directly limits this movement?
Adductor pollicis
First dorsal interosseous
Extensor pollicis longus
Opponens pollicis
15. After the first portion of shoulder abduction has been initiated, which muscle becomes the principal abductor through most of the remaining range?
Deltoid
Pectoralis major
Latissimus dorsi
Teres major
16. Which muscle is the primary elbow flexor regardless of whether the forearm is pronated or supinated?
Coracobrachialis
Biceps brachii
Brachioradialis
Brachialis