Literature Conclusions

Clinical Implications

Scapular Mechanics

• Scapular mobilization promotes greater shoulder ROM and scapular upward rotation. (1)
• The ratio of upper trapezius muscle activity vs. lower trapezius activity is higher in individuals with SIS. (19)
• Kinesio taping to the lower trapezius may be beneficial in decreasing the amount of anterior tilt of the scapula, and increasing lower trapezius muscle activity. (26)
• Individuals with shoulder impingement show later recruitment of the scapular stabilizers. (53)

It has been well documented that assessment of the mechanics of the scapula are essential to the proper treatment of shoulder pathologies.  These recent articles implicate the need to focus on the muscle activation patterns of the scapular stabilizers.  Simply doing lower trapezius strengthening exercises without looking at the activation pattern in relation to the upper trapezius may be doing a disservice to the patient.  These altered activation patterns may be addressed with kinesio taping to assist the lower trapezius and/or inhibit the upper trapezius.  Biofeedback training may be beneficial to teach the patient how to correctly active the scapular stabilizers.  As always, it is also imperative to address any issues with mobility that may be coming from the pectoralis minor or other soft tissue restrictions to proper scapular mobility.

Glenohumeral Joint Mechanics

• External rotation range of motion limitation appears to be the most important index of shoulder joint dysfunction. (30)
• End range distraction mobilizations provide greater gains in mobility than performing them in the neutral position. (37)
• Significant relationships can be found between humeral internal rotation and posterior shoulder tightness, external rotation and anterior shoulder tightness, and between anterior scapular tipping and anterior shoulder tightness. (51)

While this information is not new, it is a good reminder of how to most effectively increase the mobility in the glenohumeral joint.  A conceptual idea of what structure needs to be mobilized/stretched in order to get a particular increase in physiologic motion is essential to choosing the proper technique for the patient’s presentation.  For example, to gain internal rotation it would be most effective to perform internal rotation end range distraction and posterior glide, due to the nature of the joint mechanics.  When attempting to decide which motion to focus on to get the most benefit for the patient, it appears focusing on restoring external rotation would be most advantageous.

Muscle Activity

• Rotator cuff fatigue leads to superior migration of the humeral head on the glenoid (17)
• Pain avoidance decreases the muscle activity of the deltoid, and increased activity is seen in the pectoralis major and latissimus dorsi muscles, likely due to compensatory mechanics. (30)

When addressing the muscles affecting the shoulder joint, it is important to focus on decreasing pain to prevent inhibition of muscles and to avoid compensatory muscle activity.  Within a pain-free arc of motion, strengthening the rotator cuff will help keep the humeral head in its proper axis of rotation.  This pain-free movement will also serve to restore proper muscle coupling for appropriate activation patterns.

• Thoracic spine manipulation can improve pain reports and levels of disability in the shoulder. (38)

In the same way that proper treatment of the shoulder can not be accomplished without addressing the scapula, the thoracic spine is just as essential in promoting proper shoulder mechanics.

• Providing ergonomic intervention in concert with traditional physical therapy may be the most beneficial course of treatment.

A thorough treatment of the patient’s condition can not be accomplished if we do not address the ergonomical factors that contributed to the shoulder pathology to begin with.

• A movement system impairment classification of the shoulder dysfunction can be used to describe the pathology and guide treatment.(60)

Not all subacromial impingements can be treated the same way.  A careful look at the movement dysfunction will give us more imperative information that will guide treatment.

• Internal impingement is most affected by: glenohumeral instability, posterior capsule contracture, and scapular dyskinesis. (29, 56)

When treating a patient with signs of internal impingement addressing these three areas may provide the most benefit for the patient.