Dysfunctional Shoulder Blade Movement is Causing Shoulder Pain
A high percentage of shoulder pain conditions stem from compression during shoulder movement of the soft tissue structures that sit between the acromion bone and the humeral head. This compression is known as Subacromial Impingement Syndrome and involves compression of the supraspinatus tendon or bursa which sits between the acromion bone and humeral head. The acromion bone is like a roof that resides over the shoulder joint, and the shoulder joint is a ball and socket joint that contains the humeral head or upper arm, see attached illustration. We can feel the acromion bone by touching the boney tip of our own shoulder joints.
Scapula Dyskinesis role in Impingement
Scapula Dyskinesis, or otherwise known as abnormal shoulder blade movement, is directly involved in causing impingement between the acromion bone and humeral head. The top part of the scapula is the acromion bone. If the scapula is tilted forward, it will cause the acromion bone to tilt into a forward position. Similarly the humeral head can tilt forward narrowing the space between the acromion and humeral and causing compression of the underlying tendon. Hence treatment of the Patients shoulder pain must involve assessment and treatment of the scapula.
So what needs to be addressed to correct the Scapula Dyskenesis
Weak Lower trapezius muscle compared to an overactive Upper trapezius muscle. The excessively tight upper Trap muscle sits between the top of the shoulder and neck. It is commonly tight causing the scapula to be pulled into a forward tilting position. The Lower trapezius is situated at the end of the scapula and thus pulls the scapula downwards. Hence exercises that strengthen the Lower trapezius are important in order to balance the opposing pull on the scapula.
Tight and Stiff Pectoralis Minor muscle of the chest that pulls the Scapula into a forward tilted position. The stiffness of the Bicep tendon needs to be examined also as a short stiff bicep tendon can pull the humeral head forward. Finally the weakness of the Serratus Anterior Muscle that activated Upward Rotation, which is the shoulder blade elevating upwards as the arm in lifted overhead is commonly weak and requires retraining.
Next Week, I will continue to discuss further Shoulder Pain and Dyskinesis management.
Tomás Ryan is a Registered Physical Therapist with The Irish Association of Physical Therapy and is based in Clonmel & Thurles. Contact Number: 0504 26672. Email: firstname.lastname@example.org