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the shoulder
The shoulder Passive
elements
Active elements
Bony shoulder
Bony shoulder
Bony shoulder
Bony shoulder
ACROMION TYPES
Glenohumeral joint• Ball and socket• Ball:1/3 of a sphere• Bony glenoid:covers only 1/3 of the head• Glenoid depth: Vertical:9mm Horizontal:5mm
Glenohumeral jointAVERAGE GLENOID DEPTH DOUBLED VERTICAL >HORIZONTAL DEPTH
LABRUM• dense fibrous tissue • superior portion: resembles a meniscus loosely attached to the glenoid rim (12o'clock) inserts into the biceps tendon in The interval is a small (5 mm) recess• the lower portion: round, dense
Glenohumeral joint
Slap lesion
Slap lesion
Glenohumeral capsule• inserts primarily into the anatomic neck of
humerus but inferiorly in to the surgical neck
• Preservation of glenohumeral stability by an intraarticular vacuum
• A cadaver study:with an intact capsule found no subluxation even with sectioning of all the supporting muscles
Glenohumeral Ligaments
Glenohumeral Ligaments
Glenohumeral Ligaments• arm dependent (abduction zero):all three
ligaments are visibly slack; primary stabilizer is SGHL
• + external rotation:tension in the MGHL and the superior band of the IGHL
• >45° of abduction:tightens the superior band of the IGHL
ROTATOR INTERVAL
Coracoacromial Ligament
passively restrains humeral subluxation in the shoulder with a deficient rotator cuff
Coracohumeral Ligament• forms part of
the roof of the bicipital tendon sheath
• COVERS ROTATOR INTERVAL
ACROMIOCLAVICULAR JOINT
Sternoclavicular joint
MOTIONS OF THE SHOULDER JOINTS
ROM:160˚─180˚
SHOULDER ROMElevation: humerus→2/3
scapula→1/3
minimum in the first and the last 30˚
Rotation:
max with the arm adjacent to the trunk(160˚) decrease to 120˚in 90˚ABD/FLEX
min in full ABD/FLEX
Scapular motion
SCAPULOTHORACIC MOBILITYI. ROTATION upward(60˚) downward(extension)II. ELEVATIONIII. DEPRESSIONIV. PROTRACTION(away from
the spine)V. RETRACTION(toward the
spine)
CLAVICULAR JOINTS• sternoclavicular: only 30° during the first 90° .
. of arm elevation. . . Clavicular protraction and rotation
Clavicular rotation of 50˚
• acromioclavicular: 15° during the first and last
. 40° of arm elevation
SHOULDER MUSCLES• deltoid (anterior, middle, posterior)• rotator cuff muscles (supraspinatus,
subscapularis, infraspinatus, teres minor) plus the biceps
• axiohumeral muscles (pectoralis major and latissimus dorsi) plus the teres major
• Scapular muscle (serratus anterior, trapezius, rhomboid, and levator scapulae)
elevation• Deltoid: primary elevator• posterior part has minor role
. except during abduction
• Rotator cuff:sup.spinatus→ABD/Compression . inf.spinatus→ext.rot/depressor
subscapularis→int.rot/depressor
teres minor→ext.rot• Pec.major and lat.dorsi→depressor
The end