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scapulothoracic jt
- (not a real jt)
- Describes relationship btwn medial border of scapula and thoracic vertebrae
- Rotary Motion (glenoid fossa as pt of reference)
- - upward/downward rotation
- - int/ext rotation
- - ant/post tilting
- Translatory Motion
- - abd/adduction (as related to pro/retraction)
- - elevation/depression
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sternoclavicular jt
- sternal end of clavicle and manubrium
- complex simple jt (has a disc)
- triaxial (3 DOF)
- - z axis
- -- elevation (~ 45 degrees)
- -- depression (~15 degrees)
- - y axis
- -- protraction (~15-20 degrees)
- -- retraction (~10-15 degrees)
- - x axis
- -- rotation: arm up, clavicle rotates posterior, arm down, clavicle rotates anterior
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stabilization of sternoclavicular jt
- ant/post sternoclavicular lig
- costoclavicular lig
- interclavicular lig
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acromioclavicular jt
- lateral end of clavical and medial end of acromion
- triaxial
- - y axis
- -- int/ext rotation (or medial/lateral rotation) of scapula "winging"; internal (medial): medial border moves back, lateral border moves forward
- --- occurs in order to maintain the contact of scap with contour of rib cage.
- -x axis
- -- ant/post tipping/tilting (sup border of scap is POR)
- --- ant: acromion tilting forward & inferior angle tilting back
- --- occurs in order to maintain the contact of the scapula with the contour of the rib cage and to orient glenoid fossa
- -z axis
- -- upward and downward rotation
- -- provides a little more upward lift of arm
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stabilization of AC jt
- sup & inf acromioclavicular ligs
- coracoclavicular lig (major stabilizer)
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