what is an articulation
a joint; where two or more bones connect, surrounded by CT typically
what do joints allow in general
MOVEMENT
what is mobility
amount of movement allowed
what does movement occur due to
muscle contractions
what do joints need
stability
what is the correlation of joint stability to how prone it is to injury
more stable, less prone to injury
what can contribute to stability of a joint in general
amount of articulation, CT (ligaments and cartilage and joint capsules), muscle that cross joint
what is the relationship between stability and mobility
inverse
what is Hilton's law
nerves supplying a joint also supply the muscles moving the joint and the skin covering the insertion of those muscles (usually they are the nerves supplying proprioceptors and nociceptors of the joint
what is O'Laughlin's law
if a muscle crosses over (spans) a joint, it must move that joint
what is the mobility of synovial joints
freely moveable
what covers synovial joints
articular capsule
what is an articular capsule
CT surrounding joint, providing stability
what do synovial joints have besides an articular capsule
synovial membrane
what do synovial membranes make
synovial fluid
what is the role of the synovial fluid
provides lubrication of the joint to reduce friction in a given joint and nourishes the articular cartilage (hyaline cartilage) which surounds the end of the bone
what helps to maintain the hyaline cartilage of a joint
synovial fluid
a. sternoclavicular ligament
b. articular disc
c. costoclavicular ligament
a. transverse humeral ligament
b. coracohumeral ligament
c. acromioclavicular ligament
d. parts of coracoclavicular ligament
e. glenohumeral ligaments
what articulatinos make up the shoulder joint
sternoclavicular joint
acromioclavicular joint
glenohumeral joint
what is the stability of the SC joint
high
what is the mobility of the SC joint
very low
what does the SC joint connect
physical attachment point of pectoral girdle to axial skeleton
what makes up the rest of the pectoral girdle besides the clavicle
scapula
what is the motion of the scapula in general
glides over thoracic cage
what ligaments does the SC joint have
sternoclavicular and costoclavicular
what is the role of the sternoclavicular ligaments
help hold down clavicular head in place
where does the costoclavicular ligament run
comes off first rib and attaches to clavicle
what is the roel of the costoclavicular ligament
restricts elevation
besides the costoclavicular ligament what is a notable structure of the determination of the stability of the sternoclavicular joint
articular disc
what movement does the sternoclavicular joint allow
movement of pectoral girdle: elevates and depresses as you shrug shoulders and put them back down, clavicle rises and lowers with these
there is also some anterior/posterior movmeent that helps in protraction and retraction of shoulders, but that is more limited than elevation and depression
what innervates the sternoclavicular joint
supraclavicular nerve and nerve to subclavius
are injuries to the sternoclavicular joint rare
yes
what is dislocation of the sternoclavicular joint usually also accompanied by
tearing of sternoclavicular ligaments
what do tearing of sternoclavicular ligaments usually look like
superior swelling over sternal head, sternal head pops upward
what directions do sternoclavicular injuries usually go
anteriorly or superiorly
what usually happens before you have disruption of sternoclavicular joint due to the strength of the joint
fracture of clavicle
what types of fractures are fractures of the clavicle usually
greenstick fracture where branch splinters and does not tear completely
what does the AC joint connect
clavicle to acromion process of scapula
what are the stability and mobility of the AC joint
some stability and not much movement
what does the AC joint attach
scapula and clavicle (upper limb to axial skelton)
does the AC joint use a lot of movement
no
are the ligaments that hold the AC joint together strong
no
what are the ligaments involved in the AC joint
acromioclavicular ligament
coracoclavicular ligament
what does the acromioclavicular ligament cover
synovial membarne between clavicle and acromion process
what does the coracoclavicular ligament connect
coracoid process to clavicle
what is the role of the coracoclavicular ligament
holds clavicle down, maintains articulation between the coracoid process and clavicle
what type of injuries are common with the AC joint
sprain of acromioclavicular ligament and coracoclavicular ligament
what is a sprain
some kind of rupture of fibers of ligament/CT whether partial or complete
are sprains and dislocations different
yes
what is a type 1 AC separation
some fibers tearing but other fibers keep connections; minimal damage;
what is the treatment for a type 1 AC separation
shoulder sling
what is a type 2 AC separation
AC ligament torn, but articular surfaces are still close to one another
what is the treatment for type 2 AC separation
shoulder sling treatment
what is a type 3 AC separatino
AC and CC ligaments are torn, so you get actual separation
what is the treatment for type 3 AC separation
repaired surgically
what is considered the true shoulder joint
glenohumeral joint
what type of joint is the glenohumeral joint
ball and socket joint
what forms the glenohumeral joint
humerus and glenoid cavity of scapula
how many degrees of motion does the glenohumeral joint have
3
what are teh degrees of motion of the glenohumeral joint
flexion/extension
abduction/adduction
internal/external rotation
where does the rotation of the glenohumeral joint take place
glenoid cavity
what are teh stats of glenohumeral joint mobility and stability
very mobile, not very stable
what ligaments help the glenohumeral jiont
glenohumeral
coracohumeral
transverse humeral
coracoacromial*
how many ligamtnes are within the glenohumeral group? what are they like
3
thickened bands of CT
whattype of support do the glenohumeral ligaments provide
anterior support
what do the glenohumeral ligaments prevent
limit external rotation and hyperextension of shoulder
where do coracohumeral ligaments run
coracoid process to top of joint
what type of support do coracohumeral ligaments provide
superior support
where are the transverse humeral ligaments
between greater and lesser tubercle of humerus
what goes through the transverse humeral ligament
long head of biceps brachii
what forms a canal to hold the long head of the biceps brachii in place
transvese humeral ligament
where does the coracoacromial ligament run
coracoid process to acromion
what type of support does the coracoacromial liagment provide
superior support
what cavity does the humerus go into and what bone is that cavity part of
glenoid cavity, part of scapula
is the glenoid cavity small or large compared with the head of the humerus
small
how much stability does the glenoid cavity provide to the shoulder joint
limited stability
a. glenoid cavity
b. glenoid labrum
what is the role of the glenoid labrum
helps deepen pocket of the glenoid cavity, which increase stability due to the deeper socket
what is the glenoid labrum made of
fibrocartilage
what does a SLAP lesion stand for
superior labrum, anterior to posterior
what happens in a SLAP lesion
long head of biceps brahii attaches to glenoid labrum, so in SLAP you have pulling of the long head of the biceps tendon that tears away labrum from glenoid
what makes SLAP lesions so painful
cartilage disrutpion, which reduces stability of joint and ruins smooth, frictionless surface of joint moveemnt
what are the two concerns in a SLAP lesion
pain and a catching feelng due to a piece of cartilage flapping down between the glenoid and humerus, causing a loss of that smooth surface
a. subscapularis muscle
b. infraspinatus muscle
c. teres major muscle
d. supraspinatus muscle
what structure provides the msot stability to the shuolder
rotator cuff
how does the rotator cuff provide the msot stability to the shoulder joint
active contractions, cover anterior superior and posterior surfaces, when they tonically contract they pull humerus into glenoid to maintain glenohumeral articulation and subsequently help stability
what is a secondary role of the rotator cuff
slows down rotational motion of humerus after throwing motions
what muscle is protected by subsacromial bursa
supraspinatus
what is the initiator of shoulder abductino
supraspinatus
what happens to the subacromial space as shoulder abductino increases
narrows
what typically tears in rotator cuff tears
SS tendon
what will happen if SS tendon is torn
limits abduction
as scapula rotates what does the glenoid cavity move to do
maximize articular surface
how many degrees of scapular rotation do you get for every 2-3 degrees of humeral movement
1 degree
subacromial bursa
what is the glenoid labrum important for
maintaining glenohumeral articulation surface, critical especially when arm is overhead
what is a bursa
folding of synovial membranes
what is the function of bursas
help cushoin and protect tendon of supraspinatus
what happens in shoulder impingement
bursitis or inflammation of supraspinatus from narrowing of subacromial space
what type of motins can irritate bursa or supraspinatus
overhead
what can happen in extreme cases of the narrowing of that subacromial space
due to increased bony growth (bone spurs) to fill spaces like taht subacromial space
what innervates the rotator cuff muscles
suprascapular nerve
what innervates the deltoid
axillary nerve
what innervates the pec major
lateral pectoral nerve
medial pectoral nerve
what nerves innervate the shoulder region
suprascapular
axillary
lateral pectoral
what is a shoulder subluxation
partial dislocation that spontaneously reduces
do shoudler subluxations hurt
yes
what is a shoulder dislocation
bone slips out of position and stays out of position, resulting in a large functiona decrease
why cant most dislocations just go back into position
body spasms muscle around joint and locks it out of place
what directions are most shoulder dislocations
anterior and inferior
what is the technique for reducing a glenohumeral dislocation
tractino-countertraction: wait for muscles to relax and then muscles will pull it back int position
what is usually used in shoulder reductions to hel pout
muscle relaxants;
what should you be careful about reducing shoulders
arteries and nerves and bony areas against one another (damage)
what is the minimal articulating surface of the shoulder
abducted and externally rotated
what is the apprehension test
abduct and externally rotate arm to see if
why are joints more apt to be dislocated after they have been dislocated once
articular capsule has negative pressure sticking joints together and once disrupted that is lost for good
what type of joint is the hip joint
ball and socket
what is the articulation in the hip joint
head of femur with acetabulum of os coxae
how many degrees of movement are present in the hip joint
3
what are teh degrees of movement in the hip joint
flex/ex
ab/ad
int/ext rotation
is the hip joint mroe or less stable and mobile than the shoulder
more stable, less mobile
a. iliofemoral ligament
b. pubofemoral ligament
ischiofemoral ligament
what ligaments help the hip joint maintain stability
iliofemoral
pubofemoral
ischiofemoral
ligament of the head of the femur
what does the iliofemoral ligament prvent
hyperextension
what does the pubofemoral ligament prevent
hyperabduction
what does the ischiofemoral ligament prevent
weak, but prevents excessive internal rotation
what does the ligament of the head of the femur help support
nothing
wht does the ligament of the head of the femur do
conducts of small artery
what is close pack of the hip
extension
what is close pack
position of limb where ligaments are tight and have greatest stability
what is loose pack for the hip
flexion
what is loose pack
position of limb where ligaemnts are loose and have limited stability
what is the articular surface of the hip like
acetabulum surrounds head of the femur
why is the articular surface of the hip more stable than the glenoid cavity
deeper socket
a. medial circumflex femoral artery
b. acetabular ligament
c. ligament of head of femur
d. acetabular branch
what labrum helps the hip joint's articular surface
acetabular labrum
what nerves run through the hip joint
femoral
obturator
superior gluteal
nerve to QF
sciatic
what does the femoral nerve innervate
anterior muscles
what does the obturator nerve innervate
adductors and knee
are injuries to the hip joint common or rare
rare due to stability
is a fracture of the femoral neck common or rare
fairly common
what is the type of fracture of the femoral neck called
garden fracture
what can result from femoral neck fractures
avascular necrosis, may maintain artery to femoral head but usually insurfficienct to provide blood to fractured segment which can die off and necrose
what is osteoarthritis
wearing away of smooth articular surfaces of hyaline cartilage, lose that smooth surface
what results from osteoarthritist
lot of pain, inflammatino, some grinding
what usually helps osteoarthritis
walking around
joint replacement surgery usually needed
what types of hip dislocations are tehre
congenital and acquired
what happens in a congenital dislocation
head of femur doesnt develop in acetabulum in a good position
what is difficult in congenital hip dislocaitnos
abduction
what does the leg look like in congenital hip dislocatino
medially rotated and apparent leg length discrepancy because femur has moved upward
what are acquired hip dislocations from in general
large traumatic forces
what is someone with an acquired hip dislocatin usually unable to do
abduct hip
what does the acquired hip dislocation look like
medially rotated and usually a posterior dislocation
what part of the acetabulum is waekest
posteiror side
how are hips usually dislocated
car crash where leg pushed backward as it crashes into something