? The sternoclavicular joint is the only place that the upper extremity is actually attached to the rest of the skeleton.



? The acromioclavicular (ac joint) joint at the shoulder, joins the scapula with the clavicle.

? The glenohumeral or shoulder joint joins the humerus with the scapula.

The bones of the shoulder girdle are joined together at these 3 articulations where shoulder exercises begin.

Movement at any one of these 3 articulations may produce movement in other segments as they are all interconnected. Unfortunately, any shortening of a muscle group may cause restricted range of motion in the whole shoulder complex.

As you do shoulder exercises the muscles act in combination to produce motion. For instance, the combined motion of the scapula and humerus is called scapulohumeral rhythm and is necessary for the arm to achieve 180 degrees of elevation.

The first 30 degrees of abduction is accomplished by the humerus alone, then the scapula joins in to about 120 degrees, and finally the clavicle (collarbone) participates in the remaining 60 degrees of elevation.

Some muscles act as stabilizers for the bony parts of the shoulder complex to prevent unnecessary motion.

For instance the trapezius muscles are involved in stabilizing or depressing the scapula so you are able to more efficiently raise your arm for overhead shoulder exercises without putting the shoulder joint at risk for injury.

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Because the shoulder is a ball and socket joint it rotates in many different directions and involves various different shoulder exercises muscles and positions.

? Shoulder Extension moves the upper arm down and backward working the muscles of the triceps, teres major, posterior deltoid, and latissimus dorsi. Effective exercises to work these muscles include triceps extension with an overhead cable machine and chest expansion on the Pilates reformer or Cadillac.

? Shoulder Flexion lifts the upper arm forward and upward working the muscles of the anterior deltoid, pectoralis major, and biceps brachii. An effective exercise to work these muscles is the overhead shoulder press.

Rotating shoulder exercises work the muscles of the rotator cuff. These rotate the arm both internally and externally.

? External rotation involves the muscle groups; teres minor, infraspinatus, and posterior deltoid. External shoulder rotation using a band or cable is effective in working these muscles.

? Internal rotation of the shoulder involves the muscle groups; subscapularis, teres major, latissimus dorsi, pectoralis major, and anterior deltoid. Internal shoulder rotation using a band or cable is effective in working these muscles.

? Shoulder Abduction moves the arm laterally away from the body working the supraspinatus and middle deltoid. An effective exercise is a side or lateral arm raise using a dumbbell.

? Shoulder Adduction moves the arm toward the midline of the body and involves the muscle groups; pectoralis major, latissimus dorsi, teres major, and posterior deltoid. To effectively work these muscles pull a band or cable with your arm extended out to the side and pull it straight down toward your thigh.

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What is it about those shoulder blades?

Well, Without the shoulder blades (scapula) our arms would hang off the end of our shoulders and either have too much range without control or a lack of range because the muscles would attach directly to our ribcage.

The shoulder blades act as a stable foundation for the arm to move freely. Muscular imbalances in the shoulder girdle will cause dysfunctional movement patterns throughout the body.

The actions of the scapula not only move the shoulder blades but they assist the arm in flexion, extension, abduction, adduction, as well as lifting and lowering the shoulder girdle.

? Scapular rotation downward moves the outer tip of the scapula down and assists the arm in extension, adduction, and internal rotation. This shoulder exercise works the muscles of the pectoralis major, rhomboids, and levator scapula.

? Scapular rotation upward moves the outer tip of the scapula upward and assists the arm in flexion, abduction, and external rotation. This exercise works the muscles of the serratus anterior and upper and lower trapezius.

? Scapular protraction moves the shoulder blades forward on the rib cage and shoulder girdle in a forward direction. The muscles involved are the pectoralis minor and the serratus anterior.

? Scapular retraction moves the shoulder girdle and blades together toward the vertebral column. The muscles working here are the rhomboids and middle trapezius.

? Scapular elevation moves the shoulder girdle and blades up the back toward the ear, like a shoulder shrug. Muscles working here are the upper traps and levator scapula.

? Scapular depression moves the shoulder girdle and blades down the back and involves the pectoralis minor and lower trapezius.