6] SHoulder Flashcards
AP axis SC joint
Elevation/depression
SI axis SC joint
Protraction and retraction
Longitudinal axis SC joint
Posterior and anterior rotation
Saddle joint
sternoclavicular joint
Articulates with sternum, clavicle and 1st rib
SC joint
Plane joint
AC joint
Articulates with acromion and distal clavicle
AC joint
Improves GH stability
Shock absorption
Increases total shoulder ROM
Scapulothoracic ROM
Scapulohumeral rhythm
1/3 ST motion and 2/3 GH motion but new research says elevation requires both GH and ST motion
Scapula is oriented ?
30 deg anterior to frontal plane
Humerus orientation- angle of inclination
130 - 150
Humerus orientation - angle of Torsion
30 deg retroversion
Ball and socket joint
GH joint
Articular bony anatomy Glenoid labrum Capsule and ligaments - intra-articular pressure Adhesion-cohesion
Static factors that provide mechanical stability
Limits inferior translation
SGHL and CHL
Primary restraint to anterior translation in 45-75 deg ABDuction. Also limits ER in mid ABDuction.
Middle GH lig
Anterior band
Posterior band
Axillary pouch
3 parts of inferior GH lig
Controls inferior translation of humeral head in glenoid
inferior GH lig
- pressure within the joint is negative creating a vacuum in the joint
- venting of capsule increases translation
Negative intra-articular pressure
Characteristics of adhesion-cohesion
High tensile strength (difficult to pull apart)
Low shear strength (slide easily)
Shoulder depressors
Pec major
Lats
Move and stabilize scapula
Serratus anterior
Traps
Rotator cuff muscles and tendons function as
Dynamic ligaments
Resultant force is towards joint compression
Supraspinatus
Humeral head depressors ad apply compressive force. Reduce anterior strain on ligaments.
Posterior rotator cuff and subscapularis
Coupled force for stability
Rotator cuff and deltoid
Loss of space
Primary impingement
Excess movement
Secondary impingement
Acromial morphology Degenerative spurs - AC joint Posterior GH capsule tightness Subacromial swelling RTC weak
Primary impingement
Tissues in subacromial space
Bursa
Supraspinatus
Long head of biceps tendon
GH instability
Scapular weakness/dyskinesia
biceps/SLAP lesion
GIRD
Secondary impingement
Inflammation of subacromial bursa and RC tendons
Stage 1 Neer
Fibrosis and tendinitis
Neer stage 2
Tendo ruptures, possibly bony changes
Neer stage 3
Less than 25 years old
Reversible
Neer stage 1
25 - 40 years old
Still reversible- requires rest, anti-inflammatory modalities and meds, TE
Neer stage 2