Elbow Complex Flashcards
elbow complex includes
humeroulnar joint
radiohumeral joint
proximal radioulnar joint
humeroulnar joint
movement b/w the ulna and humerus occurs
radiohumeral joint
movement b/w the radius and humerus occurs
proximal radioulnar joint
movement b/w the radius and ulna occurs
what do all 3 joints of the elbow complex have
common capsule
common capsule leads to
injury to one joint affects other joints
motions of the elbow
physiologic motions
component motions
physiologic motions
elbow flexion/extension
supination/pronation
component motions
ADD and ABD
humeroulnar joint is
concave on convex
concave on convex –> humeroulnar joint
concave trochlear notch of ulna articulates w/ convex trochlear surface of humerus
what kind of joint is the humeroulnar joint
hinge joint
allows movement in 1 plane
flexion/extension
open packed position –>humeroulnar joint
70 degrees of flexion
10 degrees supination
closed packed position –> humeroulnar joint
extension w/ supination
capsular pattern –> humeroulnar joint
flexion > extension
flexion –> humeroulnar joint
the coronoid process (ulna) lies in the coronoid fossa (humerus)
extension –> humeroulnar joint
the olecranon (ulna) lies in the olecranon fossa (humerus)
trochlea of the humerus is –> humeroulnar joint
asymmetric with an axis superolateral to inferomedial
what does the trochlear being asymmetric cause –> humeroulnar joint
carrying angle of 10-15 degrees in males
greater than 15 degrees in females
in children and many women –> humeroulnar joint
elbow hyperextension of 5-30 is normal
olecranon process is smaller
radiohumeral joint is
concave on convex
concave on convex –> radiohumeral joint
small concave facet on radial head articulates w/ convex surface of the capitulum
radiohumeral joint has
3 degrees of freedom
flex/ext
S/P
ADD/ABD
open packed position –> radiohumeral joint
full extension and supination
closed packed position –> radiohumeral joint
90 flexion w/ 5 supination
capsular pattern –> radiohumeral joint
flex > ext
S > P
proximal radioulnar joint is
convex on concave
convex on concave –>proximal radioulnar joint
convex radial head articulates w/ the concave radial notch of the ulna
what kind of joint –>proximal radioulnar joint
uniaxial pivot joint
primary motion = S/P
open pack position –>proximal radioulnar joint
elbow flexion 70 and supination 35
close pack position –>proximal radioulnar joint
supination 5
capsular pattern –>proximal radioulnar joint
S = P
middle radioulnar articulation is made up of
radius, ulna and interosseous membrane b/w them
middle radioulnar articulation
not a true joint
when is middle radioulnar articulation at maximum stretch
in forearm neutral
fxn of middle radioulnar articulation
prevents proximal displacement of radius on ulnar
occurs w/ pushing movements
ligaments of the elbow
radial collateral ligament
ulnar collateral ligament
annular ligament of radius
oblique cord
radial collateral lig is also called
lateral lig
RCL extends from
lateral epicondyle to the humerus of the radius
what does RCL restrict
varus forces
RCL blends
distally w/ annular ligament of the radius
encircles and holds the head of the radius in the radial notch of the ulna
RCL assists in
prevention of posterior dislocation of ulna from trochlea
ulnar collateral lig is also called
medial collateral lig
UCL is a
triangular shaped lig
UCL extends from
medial epicondyle of the humerus to the coronoid process and olecranon of the ulna
UCL consists of
3 bands
3 bands of UCL
anterior cordlike band
posterior fan like band
slender oblique band
UCL restricts
valgus forces b/w 20-130 degrees
UCL assists in
prevention of posterior dislocation of ulna from trochlea
UCL and FCU muscle together
form cubital tunnel
passage of ulnar nerve
annular ligament of radius attached
only to the ulna
forms the proximal radioulnar joint
what does annular ligament allow
movement to the radial head
fxn of annular lig
keep the radius securely against the ulna
what does the annular lig provide
stability for the proximal radioulnar joint
oblique cord
connects radius to ulna
oblique cord extends from
the ulnar tuberosity just distal to the radial tuberosity
oblique cord limits
supination
oblique cord prevents
displacement of radius on ulna w/ pulling movements
primary muscles of the elbow and forearm
elbow flexors
elbow extensors
forearm supinators
forearm pronators
wrist flexors and extensors
elbow flexors
brachialis
biceps brachii
brachioradialis
elbow extensors
triceps brachii
anconeus
forearm supinators
supinator
biceps brachii
brachioradialis
forearm pronation
pronator teres
pronator quadratus
many muscles that act on the wrist and hand
are attached on the distal humerus
crosses the elbow joint
what do the wrist and hand muscles provide
stability to the elbow
but contribute little motion at elbow
what do the wrist and hand muscles allow
effective movements of the wrist and fingers
regardless of forearm position
how does the position of the elbow affect the muscles of the wrist and hand
length tension relationship of the muscles during their actions on the wrist and hand
wrist flexors
flexor carpi radialis
flexor carpi ulnaris
palmaris longus
flexor digitorum superficialis and profundus
wrist extensors
extensor carpi radialis longus and brevis
extensor carpi ulnaris
extensor digitorum
what dislocates easily up to age 8
H/R and superior R/U
esp proximal R/U joint
panner’s dz
up to age 10
most common boys ages 5-10
osteochondritis dessicans
b/w 15-20
epicondylitis/osis
35 to 50