The Shoulder Injury Progression


Contributing Writer
Dr. Alex Ognibene
Jamestown Spine

The shoulder is by far the most mobile joint in the body, with up to 180 degrees of motion in multiple planes. However, with the benefits of great motion comes the negative of also being a very unstable joint. Due to this instability, the surrounding soft tissues become damaged easily, and could result in pain, discomfort, and loss of motion.

Step 1: Scapular Dyskinesis

While shoulder injuries can occur from traumatic events, it is much more likely that the problem gradually builds up over time before resulting in symptoms. In most shoulder injury cases, the problem starts with bad mechanics of the shoulder blade, or scapula. This condition is called “scapular dyskinesis.” Scapular dyskinesis is caused mostly by posture-related muscle imbalances, or tightness in some muscles and weakness in others. These imbalances cause improper mobility of the shoulder blade during motion of the upper arm, which may lead to pain and further shoulder complications.

Step 2: Impingement

If left uncorrected, scapular dyskinesis can lead to shoulder impingement. While many ailments of the shoulder can be considered “impingement,” true shoulder impingement occurs when the top of the humerus jams into the part of the scapula known as the acromion process. When these two come together, the shoulder bursa and/or rotator cuff tendons get pinched, or impinged, between the two bones. Shoulder impingement classically presents with sharp pain while reaching overhead or behind the back, as these motions will push the humerus into the acromion.

Step 3: Rotator Cuff Disorder

Scapular dyskinesis leads to impingement, and impingement finally leads to rotator cuff disorders. Because the rotator cuff tendon is affected by the stress of the impingement, the most common problem at this phase of progression is rotator cuff tendonitis. Tendonitis occurs when inflammation pools up where the muscle inserts on bone. As this issue becomes worse, the likelihood of a rotator cuff tear increases. Rotator cuff injuries present with muscle weakness, shoulder pain (particularly at night), and limited range of motion.

The good news about shoulder problems is they can often be identified and corrected before they develop into impingement or worse. Conservative treatment to mobilize the shoulder and scapula, combined with exercises to strengthen weak muscles and lengthen tight muscles are usually a great place to start. If you are suffering from shoulder pain, talk to your doctor about best treatment options.

Yours in Health,
Dr. Alex