PHM exam #4 Questions With Complete Solutions
AB PB abducts what joints of the thumb? attaches into ext.
mech. of thumb causing IP ________. Correct Answers
abducts CMC/MCP joints of thumb
causes IP extension
abduction is more forceful on what digit because the DI
attachments are more bony here?
abduction least forceful on what digit because attachment is
more soft tissue here and more into the extensor mechanism?
Correct Answers 2nd digit
4th digit
abductor pollicis longus - prime ______ of the CMC joint bc
LOA passes ant (palmar) to joints axis of rotation. Correct
Answers prime abductor of CMC joint
-also extends CMC joint of thumb bc falls on extensor side of
AP axis
abductor pollicis longus acts in synchrony with any action of the
thenar msucles to stabilize the 1st MC so that the thenar msucles
do not produce movement at the 1st CMC joint, since APL also
produces radial dev., what other muscle should we use to
prevent wrist motion? Correct Answers ECU
action of extrinsic muscle: flexor pollicis longus Correct
Answers flexes wrist, IP/MCP and CMC joints of the thumb
,action of the extrinsic muscle: abductor pollicis longus Correct
Answers flexes wrist
PRIME ABDUCTOR OF THE CMC JOINT OF THUMB
extends 1st cmc joint in plane of palm
action of the extrinsic muscle: extensor pollicis brevis Correct
Answers causes wrist flexion and MCP/CMC extension
action of the extrinsic muscle: extensor pollicis longus Correct
Answers extends wrist, IP/MCP/CMC joints of the thumb
-this is the only muscle that extends the IP joint directly!! all
other muscles attach to extensor mechanism in the thumb
-passes dorsal to joint axis for abduction/adduction so causes
adduction at that joint
action of the thenar eminence muscle: 1st dorsal interosseous
Correct Answers not really a part of the thumb but this muscle
attaches on radial side of 2nd MC and ulnar side of 1st MC
-attaches on the radial side of the base of the 2nd prox. phalanx
and ext. expansion
action of the thenar eminence muscle: adductor pollicis Correct
Answers forms bulk of the webspace between 1st and 2nd MC's
-adducts 1st MP joint by approximating 1st and 3rd MC's and
has transverse/oblique heads
-depending on CMC's initial position, this muscle can flex the
MP joint and assist with IP extension through its attachment to
the ext. mechanism
,action of the thenar eminence muscle: flexor pollicis brevis
Correct Answers ulnar head: usually classified as 1st palmar
interosseous, crosses only MP joint
radial head: flexes CMC and MP joints
action of the thenar eminence muscle: opponens pollicis Correct
Answers crosses only CMC joint
-oblique fibers abduct, flex, rotate CMC to oppose thumb to
other digits
action of the thenar eminence muscles: abductor pollicis brevis
Correct Answers abducts the MCP joint
IP extension bc fibers attach to extensor mech of the thumb
activity in the intrinsic muscles that attach to to extensor
mechanism always produce DIP and PIP what? Correct
Answers extension
activity in the triceps during forceful gripping? Correct
Answers use FDS/FDP to grip
also need to use ECRL/B and ECU to stabilize the wrist so their
is no deviation, prevent over shortening fo long finger flexors
and prevent loss of grip strength
-problem is ECRL which is an elbow flexor, we need to use
triceps an elbow extensor to cancel that action out and stabilize
elbow
adductor pollicis has two heads and causes what two actions?
useful in pinching object between thumb and index finger or
when using scissors Correct Answers causes adduction and
flexion
, are the IP joints of the fingers also supported by UCL, RCL, and
smaller volar plates? Correct Answers yes
at the radiocarpal joint what axis? close packed position?
at the midcarpal joint what axis? close packed position? Correct
Answers RC - lateral axis with flex/ext. CPP= extension
MC - AP axis with rad/uln deviation, CPP=ext.
axis' of thumb for abduction/adduction, flexion/extension occur
through what bone in the hadn Correct Answers trapezium
close-packed position of CMC joint of thumb Correct Answers
extremes of opposition which prevents CMC rotation and
extremes of reposition
CMC flexion and abduction makes what?
CMC extension and adduction makes what? Correct Answers
oppostion
reposition
damage to this nerve can result from a gunshot/stabbing wound
or fracture of humerus/radial head, also saturday night palsy
Correct Answers radial nerve
damage to this nerve occurs when trauma to elbow region
patient experiences wasting of web spaces and interosseous
spaces Correct Answers ulnar nerve
AB PB abducts what joints of the thumb? attaches into ext.
mech. of thumb causing IP ________. Correct Answers
abducts CMC/MCP joints of thumb
causes IP extension
abduction is more forceful on what digit because the DI
attachments are more bony here?
abduction least forceful on what digit because attachment is
more soft tissue here and more into the extensor mechanism?
Correct Answers 2nd digit
4th digit
abductor pollicis longus - prime ______ of the CMC joint bc
LOA passes ant (palmar) to joints axis of rotation. Correct
Answers prime abductor of CMC joint
-also extends CMC joint of thumb bc falls on extensor side of
AP axis
abductor pollicis longus acts in synchrony with any action of the
thenar msucles to stabilize the 1st MC so that the thenar msucles
do not produce movement at the 1st CMC joint, since APL also
produces radial dev., what other muscle should we use to
prevent wrist motion? Correct Answers ECU
action of extrinsic muscle: flexor pollicis longus Correct
Answers flexes wrist, IP/MCP and CMC joints of the thumb
,action of the extrinsic muscle: abductor pollicis longus Correct
Answers flexes wrist
PRIME ABDUCTOR OF THE CMC JOINT OF THUMB
extends 1st cmc joint in plane of palm
action of the extrinsic muscle: extensor pollicis brevis Correct
Answers causes wrist flexion and MCP/CMC extension
action of the extrinsic muscle: extensor pollicis longus Correct
Answers extends wrist, IP/MCP/CMC joints of the thumb
-this is the only muscle that extends the IP joint directly!! all
other muscles attach to extensor mechanism in the thumb
-passes dorsal to joint axis for abduction/adduction so causes
adduction at that joint
action of the thenar eminence muscle: 1st dorsal interosseous
Correct Answers not really a part of the thumb but this muscle
attaches on radial side of 2nd MC and ulnar side of 1st MC
-attaches on the radial side of the base of the 2nd prox. phalanx
and ext. expansion
action of the thenar eminence muscle: adductor pollicis Correct
Answers forms bulk of the webspace between 1st and 2nd MC's
-adducts 1st MP joint by approximating 1st and 3rd MC's and
has transverse/oblique heads
-depending on CMC's initial position, this muscle can flex the
MP joint and assist with IP extension through its attachment to
the ext. mechanism
,action of the thenar eminence muscle: flexor pollicis brevis
Correct Answers ulnar head: usually classified as 1st palmar
interosseous, crosses only MP joint
radial head: flexes CMC and MP joints
action of the thenar eminence muscle: opponens pollicis Correct
Answers crosses only CMC joint
-oblique fibers abduct, flex, rotate CMC to oppose thumb to
other digits
action of the thenar eminence muscles: abductor pollicis brevis
Correct Answers abducts the MCP joint
IP extension bc fibers attach to extensor mech of the thumb
activity in the intrinsic muscles that attach to to extensor
mechanism always produce DIP and PIP what? Correct
Answers extension
activity in the triceps during forceful gripping? Correct
Answers use FDS/FDP to grip
also need to use ECRL/B and ECU to stabilize the wrist so their
is no deviation, prevent over shortening fo long finger flexors
and prevent loss of grip strength
-problem is ECRL which is an elbow flexor, we need to use
triceps an elbow extensor to cancel that action out and stabilize
elbow
adductor pollicis has two heads and causes what two actions?
useful in pinching object between thumb and index finger or
when using scissors Correct Answers causes adduction and
flexion
, are the IP joints of the fingers also supported by UCL, RCL, and
smaller volar plates? Correct Answers yes
at the radiocarpal joint what axis? close packed position?
at the midcarpal joint what axis? close packed position? Correct
Answers RC - lateral axis with flex/ext. CPP= extension
MC - AP axis with rad/uln deviation, CPP=ext.
axis' of thumb for abduction/adduction, flexion/extension occur
through what bone in the hadn Correct Answers trapezium
close-packed position of CMC joint of thumb Correct Answers
extremes of opposition which prevents CMC rotation and
extremes of reposition
CMC flexion and abduction makes what?
CMC extension and adduction makes what? Correct Answers
oppostion
reposition
damage to this nerve can result from a gunshot/stabbing wound
or fracture of humerus/radial head, also saturday night palsy
Correct Answers radial nerve
damage to this nerve occurs when trauma to elbow region
patient experiences wasting of web spaces and interosseous
spaces Correct Answers ulnar nerve
