the shoulder complex Flashcards
what bones make up the shoulder complex?
humerus
scapula
clavicle
what joint connects the shoulder to the axial skeleton?
sternoclavicular joint
what is the primary mechanism that serves for securing the shoulder girdle to the rest of the body?
suspensory muscles
what are the three anatomical joints that make up the shoulder complex?
sternoclavicular joint
acromioclavicular joint
glenohumeral joint
what is the functional joint that makes up the shoulder complex?
scapulothoracic joint
what is particular about the scapulothoracic joint?
its not a true joint, it has no boney articulation between the scapula and thoracic cage, movement produced is that of the scapula gliding on the thoracic cage
what articulates in the GH joint?
the small glenoid fossa with the head of the humerus
what is the GH joint often referred to as?
the shoulder joint
what motions can be accomplished by the sternoclavicular joint?
elevation/depression
protraction/retraction
anterior/posterior rotation of the clavicle
what type of mvmt occurs at the acromioclavicular joint?
minimal movement but will participate in elevation and depression, protraction/retraction
anterior/posterior rotation of the clavicle
what enhances the glenoid fossa?
the glenoid labrum
what has the GH joint sacrified to serve the mobility needs to the hand?
sacrified congruency
what mvmts can be accomplished by the GH joint?
flexion/extension
add/abd
IR/ER
What is the GH joint susceptible to?
degenerative changes and dernagement
what are the shoulder muscles responsible for?
F/E
ABD/ADD
ER/IR
What is the Scapulothoracic motion a part of?
part of a true closed chian with SC and AC joints thus movement of ST will result in motion of AC and/or SC joint
what type of motion occurs at the ST joint?
Elevation/depression
protraction/retraction
up/down rotation
what motion occurs to keep the scapula relatively flushed with the curved rib cage?
smaller motion of the medial/lateral rotation and anterior/posterior tipping of the ST joint
scapular muscles are responsible for what types of mvmts?
Elevation/depression
protraction/retraction
up/down rotation
what is the general AROM/PROM of flexion in the shoulder?
160-180 degrees
what is the general AROM/PROM of extension in the shoulder?
50-60
what is the general AROM/PROM of ABD in the shoulder?
180
what is the general AROM/PROM of IR in the shoulder?
60-100
what is the general AROM/PROM of ER in the shoulder?
80-90 degrees
what is the normal end feel in the shoulder during Flexion, extension, ABD, IR/ER
capsular
what muscles make up the rotator cuff? what is their main function?
supraspinatus
infraspinatus
teres minor
subscapularis
what is the main function of the rotator cuff muscles? how is it accomplished?
serve as dynamic stabilizers to the GH joint by compressing the head of the humerus into the glenoid fossa
creates an inferior translator pull to offset the superior pull of the deltoid during abd (infra, teres and sub)
creates a superior force against gravity with ABD (supraspinatus)
would the GH joint be able to account for the full ROM of the shoulder by itself?
no, its the coordinated function of the shoulder complex that allows it to achieve the greatest ROM,
what helps provide the remaining ROM to the GH joint?
the ST joint via the AC and SC joints during upwards rotation of the scapular induced by the trapezius and serratus anterior
what is the ST rhythm?
the concomitant GH and ST motion
summerize in 3 points the main effect of the combined Scapulohumeral motion
- the motion is distributed between GH and ST joints
- it maintains the glenoid fossa in an optimal position to recieve the head of the humerus, increasing joint congruency while decreasing shear forces
- permits musscles acting on the humerus to maintain good length-tension relation while minimizing of preventing active insufficency of GH muscles
what are some orthopedics capsular patterns?
arthritis
frozen shoulder