Scapulohumeral Rhythm

Scapulohumeral Rythm:

For every 2 degrees abduction of the humerus, there is 1 degree upward rotation of the scapula (this is an average, it varies throughout the range) 
Reverse Scapulohumeral Rythm: is seen in cases such as frozen shoulder and rotator cuff tears

Movements

1. Glenohumeral: abduction (deltoids, supraspinatus)
   1. Scapular: upward rotation (serratus anterior, trapezius)
   2. Clavicle: elevation
2. Glenohumeral: adduction (latissimus dorsi, teres major, pectoralis major (sternal))
   1. Scapular: downward rotation (rhomboids, pectoralis minor)
   2. Clavicle: depression
3. Glenohumeral: flexion (anterior deltoid, pectoralis major (clavicle), biceps brachii, coracobrachialis)
   1. Scapular: upward rotation (serratus anterior, trapezius) abduction (serratus anterior, pectoralis minor)
   2. Clavicle: elevation, protraction
4. Glenohumeral: extension (latissimus dorsi, teres major, posterior deltoid, triceps brachii)
   1. Scapular: downward rotation (pectoralis minor, trapezius) adduction (rhomboids, trapezius)
   2. Clavicle: depression, retraction
5. Glenohumeral: hyperextension (posterior deltoid, teres major, latissimus dorsi)
   1. Scapular: upward tilt (pectoralis minor)
   2. Clavicle: rotation
6. Glenohumeral: External Rotation (infraspinatus, teres minor)
   1. Scapular: adduction (rhomboids, trapezius)
   2. Clavicle: retracion
7. Glenohumeral: Internal Rotation (subscapularis, latissimus dorsi, teres major, pectoralis major)
   1. Scapular: abduction (pectoralis minor, serratus anterior)
   2. Clavicle: protraction

Scapular positioning (scapular spines begin medially at the T3 level) the scapula itself should go from the T2 to T7 spinous processes. Sprengel's deformity is a congenitally high or undescending shoulder.

http://209.85.173.132/search?q=cache:1tiDqGpfvHkJ:www.engr.panam.edu/~rafree/IntroBioMech/ShoulderComplex/Shoulder%2520Anatomy.doc+sternum+clavicle+biomechanic&cd=16&hl=zh-TW&ct=clnk&gl=tw&client=firefox-a