Flexor and extensor forearm Flashcards
Erb’s palsy
Upper brachial plexus injury
C5, 6
Upper limb is adducted, medially rotated, lies at side with forearm extended
Klumpke’s palsy
Lower brachial plexus injury
C8, T1
Affects muscles and sensation on medial side and forearm and in hand
medial cutaneous n. of arm, forearm
ulnar n.
Could be from putting upward traction on lower n. roots
Anterior compartment of arm
forearm flexion (b, b) arm flexion (c)
musculocutaneous n.
Posterior compartment of arm
extends forearm at elbow
radial n.
Anterior compartment of forearm
flex hand at wrist, flex digits, pronate forearm
median n., some ulnar n.
Posterior compartment of forearm
extend hand at wrist, extend digits, supinates forearm
radial n.
Carrying angle
between humerus and ulna
normally 10-15 degrees
allows your forearms to clear the hips when swinging arms
Thickenings of the ante brachial fascia
flexor and extensor retinaculae on the anterior and dorsal of the wrist
Distal bony features of humerus
medial/lateral epicondyle
condyle
capitulum (round head)
trochlea (pulley)
Bony features of radius
radial head
radial tuberosity
Dorsal (Lister’s) tubercle
Bony features of ulna
coronoid process trochlear notch radial notch ulnar head ulnar tuberosity olecranon
lateral ligaments of elbow
radial collateral ligament
annular ligament of radius
annular ligament of radius
encircles head of radius
medial ligaments of elbow
ulnar collateral ligament
Nursemaid’s elbow
- head of radius pops out (subluxation)
Dislocated elbow joint
ulna can be dislocated from humerus
could be from falling forward on outstretched hand
Olecranon bursae
subtendinous olecranon bursa (under triceps tendon)
subcutaneous olecranon bursa (between triceps and olecranon)
Olecranon bursitis
could be via elbow injury, repeated leaning on hard surface, infection
Colles’ fracture
Extension fracture of the radius
Trying to brace fwd fall
DINNER FORK deformity
Smith’s fracture
flexion fracture of radius
Nightstick fracture
middle third ulna
8 carpal bones (proximal row vs. distal row)
triquitrium pisiform lunate scaphoid trapezium ^proximal row
hamate
capitate
trapezoid
^distal row
Carpal tunnel
median n.
flexor digitorum superficialis
flexor digitorum profundus
flexor pollicis longus
scaphoid fracture
difficult to heal bc not very vascular (esp proximal pt of scaphoid)
displaced fracture –> surgery often recommended w/ screw or pins inserted to stabilize fracture
cubital fossa
brachial a divides into radial a and ulnar a
median n. crosses down into forearm, divides into a deep branch (anterior interosseous n.)
Ulnar a. path in forearm
ulnar a. –> common interosseous a. which divides into anterior and posterior interosseous artery (supply ant/post)
radial and ulnar a. –> join in ____, form …
join in hand, form superficial and deep palmar arches
superficial veins of arm/forearm/hand
cephalic v.
median cubital v.
basilic v.
begin at dorsal venous plexus
deeper veins accompany the arteries (w/ same names) –> “venae commitantes”
anterior forearm
flexion, adduction, abduction of hand at wrist joint
flexion of digits, incl. thumb
protonation
median n. and ulnar n.
posterior forearm
extension, adduction, abduction of hand at wrist joint
extension of digits, including thumb
supination
radial n.
Exception that applies to brachoradialis m.
Exception to rule that radial n. supplies muscles that extend
(brachioradialis –> FLEXES forearm, but supply by radial n.)
flexor palmaris longus tendon is continuous with…
palmar aponeurosis
Dual innervation of flexor digitorum profundus
lateral half (digits 2&3) –> anterior interosseous n.
medial half (digits 4&5) –> ulnar n.
Ulnar n. supplies 1.5 forearm muscles… which ones
flexor carpi ulnaris
and medial half of flexor digitorum profundus
Carpal tunnel syndrome
compression of MEDIAN n. as it passes thru carpal tunnel
inflame of FLEXOR TENDONS of digits due to repetitive motions, may exacerbate previous condition
numbness, tingling on palmar surface of thumb, index, middle and lateral half of ring fingers
weakness in opposing, flexing, abducting thumb, and flexing index, ring fingers @ MP joints
(compression of recurrent branch of median n.
Carpal tunnel tx syndrome
Phalen’s maneuver: hold wrist in complete and forced flexion 30-60 sec.
- lumbricals can be dragged into the carpal tunnel w/ flexor digitorum profundus contraction ( causes increased pressure in carpal tunnel
Tinel’s sign: performed by lightly tapping (percussing) over nerve to elicit sensation of tingling or “pins and needles” in distribution of median n.
How to locate median n. location
Just lateral to flexor palmaris longus
How to locate radial a.
Just lateral to flexor carpi radialis
Ulnar n. Cutaneous innervation
medial palmar/dorsal side of hand
little finger and half of ring finger
Ulnar n. passes behind …
medial epicondyle
does NOT go thru carpal tunnel
cubital tunnel syndrome
compression of ulnar n. as it passes between medial epicondyle and olecranon
numbness/tingling along 5th digit, medial side of 4th digit and hand
weakness in flexing DIPs of 5th and 4th digits and intrinsic m. of hand
“CELL PHONE ELBOW”
wasting of muscles in thenar eminence of both hands may indicated
untreated bilateral carpal tunnel syndrome
sensory area of radial n.
posterior arm and forearm
dorsolateral portion of hand
Within the cubital fossa, the radial n. divides into …
deep branch of radial n. (supinator m. and other extensor m.)
superficial branch of radial n. (sensory to dorsolateral hand)
Radial n. injury in axilla
affects triceps and extensor m. of wrist/fingers
–> WRIST DROP
loss of sensation in …
posterior arm and forearm
dorsolateral portion of hand
Midshaft fracture of humerus may lead to …
wrist drop
spares ability to extend forearm bc triceps already innervated by branches that come off more proximally
Saturday night palsy
compression of radial n. in axilla/upper arm in pt sleeping w/ arm over back of chair, or by crutch
Later epicondylitis
tennis elbow
via sx stretching of common extensor tendon
(when wrist/digits are extended)
Primary pathology: tendonitis of EXTENSOR CARPI RADIALIS BREVIS
OR an obj is repeatedly gripped (power grip via FCRB, FCRL, FCU)
the posterior interosseous n. is a continuation of ___ after passing the …
the deep radial n., after passing supinator
posterior interosseous n. supplies deep m. to ____ and ____
thumb and index finger
Extensor pollicus longus pivots on…
dorsal (Lister’s) tubercle
Borders of the anatomical snuff box
Lateral –> tendon of extensor pollicis brevis and aBductor pollicis longus
Medial –> tendon of extensor pollicis longus
Path of radial a. to hand
radial a. passes through anterior forearm to floor of snuff box, winds around back of thumb and comes anterior to palm of hand –> makes anastomosis with ulnar a. –> deep and superficial palmar branches
Of all the muscles in posterior forearm, which two are supplied by the radial n. itself before it divides?
brachoradialis
extensor carpi radialis longus
damage to axillary n. would cause loss of sensation to…
skin of posterior/anterior arm around inferior deltoid region
Which m. are originating from common flexor tendon?
flexor carpi radialis
flexor palmaris longus
flexor carpi radialis
flexor digtorum superficialis
Which m. are originating from common extensor tendon?
extensor carpi radialis longus extensor carpi radialis brevis extensor digitorum extensor digiti minimi extensor carpi ulnaris
ulnar n. injury
inability to flex 4th, 5th digits at DIP joints, due to paralysis of medial half of FDP as well as at MP joints due to paralysis of lumbricals
ulnar n. can be compressed as it passes between the two heads of the flexor carpi ulnaris
CLAW HAND –> permanent extension of 4th and 5th digits
signs of injury to deep branch of radial n.
weakness in supination
loss of ability to extend wrist
loss of ability to extend metacarpophangeal joints of all digits
If ____ damaged in axilla, triceps and all extensor muscles of wrist, fingers affected
radial nerve
