Flashcards in Elbow and Wrist anatomy Deck (52):
how many degrees of freedom does the elbow have?
where do the flexor muscles originate?
medial epicondyle of the humerus
where do the extensor muscles originate?
lateral epicondyle of the humerus
which ligament anchors radius to the ulna?
what type of joint is the radioulnar jt?
pivot (pronation, supination)
when is there no contact between humerus and radius?
what reinforces the elbow capsule?
ligaments and tendons of muscles
it is otherwise weak
what is normal carrying angle of the arm?
cubitus valgus (15 degrees)
what are the parts of the medial (ulnar) collateral ligament?
anterior (most resistant to valgus force)
what is the shape of the lateral (radial) collateral ligament?
which elbow ligament is stronger?
who are major elbow flexors?
who are the major elbow extensors?
where does the short head of the biceps originate?
how many joints does the biceps affect?
2 (shoulder, elbow)
(2 joint muscles tend to cause more clinical problems)
what is the function of the coracobrachialis?
primarily a shoulder flexor
where does the brachialis insert?
coronoid process of the ulna
which is the thickest of the flexor muscles?
where is the O/I of the brachioradialis?
O: lateral supracondylar ridge
I: radial styloid process
when is the brachioradialis NOT active?
when is brachioradialis MOST active?
load and forearm is pronated (biceps is best during supination)
where does the long head of the triceps originate?
infraglenoid tubercle of scapula
where do the medial and lateral heads of triceps originate?
where do all 3 heads of the triceps insert?
what is the anconeus muscle?
small triangle muscle
O: lateral epicondyle to olecranon
what lines the inside of the annular ligament?
which forearm bone takes 80% of the weight bearing?
what are the ligaments present at the radioulnar joint?
when is the interosseus ligament tense?
when forearm is neutral (its relaxed when fully pronated or supinated)
what type of bone is the pisiform?
what type of joints are the midcarpal joints?
plane joints with no true capsule
which muscles make up the snuff box?
extensor pollicus longus
extensor pollicus brevis
why are snuff box injuries dangerous?
low, low perfusion
what are the dorsal radiocarpal ligaments??
from radial styloid to the lunate and and triquetrum (contact between lunate and radius)
what are the volar radiocarpal ligaments?
radiotriquetral (strongest and supports lunate)
what are attachments of ulnar collateral ligament of the wrist?
from ulna to pisiform and triquetrum
what are the attachments of radial collateral ligament of the wrist?
from radius to scaphoid, trapezium and 1st MC
what are the attachments of the ulnocarpal ligament?
triangular fibrocartilage to lunate and capitate
which nerve innervates most of the flexor muscles of the forearm?
median nerve (except for flexor carpi ulnaris)
what action do flexor digitorum superficialis do?
movement at PIP joint (not DIP) phalnx 2-5
what does flexor digitorum profundus cause?
DIP joints of phalnx 2-5
what innervates flexor digitorum profundus?
ulnar and median nerve
what action does flexor pollicis longus do?
what innervates most of the extensor muscles?
who is the largest carpal bone and the keystone of the proximal transverse arch?
what gives MCP joints their stability?
what joint is doing the work for the thumb?
CMC joint (that's the saddle joint) not the MCP
what is the functional positional of the hand?
claw look (beer grasp)
tenodesis (important for quadroplegics)
which nerve innervates the intrinsic hand muscles?
what are lumbricals?
intrinsic muscle of the hand that pulls hand into a bucket position
what is the role of the interossei muscles?