Muscles of the Forearm
the hypothenar eminence contains these 3 muscles that are concerned with movements of fifth digit
1. abductor digiti minimi 2. flexor digiti minimi brevis 3. opponens digiti minimi
the thenar eminence contains these 3 muscles that are concerned with movements of first digit
1. abductor pollicis brevis 2. flexor pollicis brevis 3. opponens pollicis
Which of these muscles is an intrinsic hand muscle that moves the thumb (i.e. the first digit)? a.) Flexor pollicis brevis b.) Abductor digiti minimi c.) Flexor pollicis longus d.) Extensor pollicis longus e.) Flexor digiti minimi
a.) Flexor pollicis brevis
Which muscle(s) place your digits into the writing position? a.) Lumbrical mm. b.) Palmar interossei mm. c.) Flexor digitorum superficialis m. d.) Opponens pollicis m. e.) Dorsal interossei mm.
a.) Lumbrical mm.
The __________ muscle is absent on one or both sides in about 14% of people. a.) palmaris longus b.) flexor carpi radialis c.) pronator teres d.) flexor digitorum superficialis e.) flexor carpi ulnaris
a.) palmaris longus
the 3 dorsal interossei are responsible for what action
abducting the digits (DAB)
action of abductor digiti minimi
abduction of digit 5
other deep muscles of the posterior forearm
abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis
action of abductor pollicis brevis
abducts digit 1
action of abductor pollicis longus
abducts digit 1 and extends digit 1
the 3 palmar interossei are responsible for what action
adducting the digits (PAD)
action of adductor pollicis
adducts pollex
insertion of supinator
all surfaces of the proximal third of radius
origin of the deep group of the anterior forearm
anterior surfaces of ulna, radius, and interosseous membrane
anconeus
assits in forearm extension (elbow)
where are interosseous muscles located
between the metacarpal bones
the 3 muscles that assist brachialis flex the elbow
biceps brachii, pronator teres, brachioradialis
What anterior forearm muscle typically has a dual innervation? a.) Pronator quadratus m. b.) Palmaris longus m. c.) Flexor digitorum profundus m. d.) Flexor carpi ulnaris m. e.) Flexor carpi radialis m.
c.) Flexor digitorum profundus m.
Jane slipped on the ice and hit her arm when she fell, which resulted in a medial epicondyle fracture and damage to the muscles originating from this location. Which deficit is MOST likely to be encountered due to Jane's injury? a.) Inability to extend the wrist b.) Inability to grasp a piece of paper tightly between the extended 2nd and 3rd fingers c.) Inability to flex the wrist d.) Inability to abduct the wrist e.) Inability to oppose the thumb
c.) Inability to flex the wrist
Which structure does NOT pass through the carpel tunnel? a.) Median n. b.) Tendon of flexor pollicis longus m. c.) Ulnar a. d.)Tendons of flexor digitorum profundus m. e.) Tendon of flexor carpi radialis m.
c.) Ulnar a.
Which of the following muscles is innervated by the ulnar nerve? a.) Flexor pollicis longus m. b.) Extensor pollicis longus m. c.) Abductor pollicis brevis m. d.) Abductor digiti minimi m. e.) Opponens pollicis m.
d.) Abductor digiti minimi m.
Abduction of the thumb is when the thumb is moved __________. (Note: Remember to start from the anatomical position.) a.) posteriorly b.) laterally away from the palm c.) medially across the palm d.) anteriorly
d.) anteriorly
insertion of pronator quadratus
distal quarter of the anterior surface of radius
origin of pronator quadratus
distal quarter of the anterior surface of ulna
Which of the following muscles does NOT extend the wrist? a.) Extensor carpi ulnaris m. b.) Extensor digitorum m. c.) Extensor carpi radialis longus m. d.) Extensor carpi radialis brevis m. e.) Brachioradialis m.
e.) Brachioradialis m.
action of extensor pollicis brevis
extends digit 1
action of extensor pollicis longus
extends digit 1
action of extensor digiti minimi
extends digit 5 and extends hand
action of extensor digitorum
extends digits 2-5 and hand
action of extensor carpi radialis brevis
extends hand and abducts hand
action of extensor carpi radialis longus
extends hand and abducts hand
action of extensor carpi ulnaris
extends hand and adducts hand
Muscles found within the posterior forearm compartment are responsible for _______.
extension of the fingers
other superficial muscles of the posterior forearm
extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi lunaris, anconeus
posterior forearm muscles are considered the major ________ of the hand (wrist) and digits
extensors
action of lumbrical muscles
flex MP joint 2-5 and extend IP joint 2-5 (writing position)
action of opponens digiti minimi
flexes and rotates digit 5, bringing digit 5 into opposition with digit 1
action of flexor pollicis brevis
flexes digit 1
action of flexor digiti minimi brevis
flexes digit 5
action of flexor digitorum superficialis
flexes digits 2-5 and flexes hand
action of the flexor digitorum profundus
flexes digits 2-5 and flexes hand
action of brachioradialis
flexes forearm (elbow)
action of palmaris longus
flexes hand
action of flexor carpi radialis
flexes hand and abducts hand
action of flexor carpi ulnaris
flexes hand and adducts hand
action of the flexor pollicis longus
flexes hand and digit 1
other muscles within superficial group of the anterior forearm
flexor carpi radialis, palmaris longus, flexor carpi lunaris, and flexor digitorum superficialis
other muscles in the deep group of the anterior forearm
flexor digitorum profundus, flexor pollicis longus
muscles of the anterior forearm is the major _____ of the hand (wrist) and digits.
flexors
extensor indicis
helps extends digit 2
action of opponens pollicis
helps opposition
origin of the muscles of the superficial group of the posterior forearm
lateral epicondyle
origin of supinator
lateral epicondyle of humerus, crest of ulna
insertion of brachioradialis
lateral surface of distal end of radius (proximal to the styloid process) (does not cross the wrist joint)
innervation of flexor digitorum profundus
medial (ulnar) half: ulnar nerve lateral (radial) half: median nerve
origin of the superficial group of the anterior forearm
medial epicondyle
origin of pronator teres
medial epicondyle of the humerus; coronoid process of ulna
innervation of the muscles of the anterior forearm
median and/or ulnar n.
innervation of pronator teres
median n.
innervation of flexor carpi radialis
median nerve
innervation of flexor digitorum superficialis
median nerve
innervation of lumbricals 1 & 2
median nerve
innervation of palmaris longus
median nerve
innervation of pronator quadratus
median nerve
innervation of the flexor pollicis longus
median nerve
the 3 muscles contained in thenar eminence are innervated by ______
median nerve
insertion of pronator teres (superficial)
middle of lateral surface of radius
origin of the muscles of the deep group of the posterior forearm
posterior surfaces of the radius, ulna, and interosseous membrane
action pronator quadratus
pronates forearm (primary) (assisted by pronator teres)
action of pronator teres
pronates forearm, flexes forearm
flexor digitorum superficialis muscle is _____ to these four muscles
pronator teres, flexor carpi radialis, flexor carpi lunaris, and palmares longus
innervation
radial nerve
innervation of brachioradialis
radial nerve
muscles of both the posterior arm and forearm are innervated by _______
radial nerve
origin of brachioradialis
ridge superior to the lateral epicondyle of humerus (the supracondylar ridge of humerus)
action of supinator
supinates forearm (radioulnar) (assisted by biceps brachii)
the lumbrical muscles originates from _________
the tendons of the flexor digitorum profundus
all interosseous muscles are innervated by ________
ulnar nerve
all muscles contained in the hypothenar eminence are innervated by _______
ulnar nerve
innervation of flexor carpi ulnaris
ulnar nerve
innervation of lumbricals 3 & 4
ulnar nerve
the main innervation of the intrinsic muscles of the hand
ulnar nerve (5 muscles innervated by the median nerve)
action of palmaris brevis
wrinkles skin of palm to aid in gripping
