SportsMed: A ‘SICK’ scapula — is that contagious?
Part one of this two-part series examines the shoulder and injury prevention
Shoulder injuries are prevalent among athletes with constant overhead movement of their arms, and susceptibility increases with the progressively greater demands imposed by a high level of competition. Many young athletes are participating in high-demand overhead activities such as volleyball and tennis that involve a very high volume of repetitive motions and exertions. The mechanical demands placed on the small contact area of the articulating surfaces can be compared to that of a basketball balancing on a teacup saucer.
The size of the articulating surface of the humeral head (i.e., upper arm bone) far exceeds the size of the articulating surface of the glenoid fossa of the scapula (i.e., shoulder blade). As a result, maintaining a balance among the forces that act on the shoulder joint is essential to facilitate proper contact of the articulating surfaces. Imbalances may result in improper positioning of the humeral head, leading to excessive wear and tear on the shoulder. In this two-part article, we discuss assessment of shoulder function and the most effective forms of injury prevention and rehabilitation.
Scapular malposition means that the scapula is incorrectly positioned. Inferior medial border prominence means that the lower inside margin of the scapula projects outwardly. Coracoid pain and malposition refers to the bony prominence beneath the clavicle (i.e., collar bone) is incorrectly positioned and painful with movement. All of these problems collectively define a SICK scapula.
An improperly functioning scapula creates stresses on muscle and bone tissues surrounding the shoulder. This can make an athlete more susceptible to a rotator cuff strain or tear, labral tear or neurological symptoms.2 The SICK scapula could also be a result of various shoulder conditions. With an unstable scapula, the athlete has a much greater risk for prolonged recovery and loss of playing time. An injury to the shoulder also affects the athlete’s daily activities. Depending on the injury, it could affect the athlete for the rest of his or her life. If the injury involves neurological pathology, improper care could lead to major disability.
Overhead athletes are prone to having scapular dyskineses (i.e., SICK scapula) because of demands that are placed upon the shoulder and surrounding articulations. One thing that can contribute to an athlete developing shoulder problems is imbalanced strength and flexibility between anterior (front) and posterior (back) muscles. Too much emphasis on the development of anterior muscles combined with inadequate flexibility and insufficient development of posterior muscles can adversely affect control of the scapula during shoulder movements. Shoulder strength training programs need to include exercises for scapula stabilizing muscles (trapezius, serratus anterior, rhomboid major, rhomboid, minor, levator scapulae and latissimus dorsi), which maintain proper scapula position.
The rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis) should also be included. Weakness of the rotator cuff can lead to Glenohumeral Internal Rotation Deficit (GIRD), which can increase susceptibility to a tear of the labrum (i.e., fibrocartilage ring around glenoid fossa) or rotator cuff. Basically, an athlete with GIRD exhibits rounded shoulders, uneven shoulder height, muscle tightness, scapular winging (outward protrusion of the inner margin), muscle soreness or a “dead arm” sensation.
To reduce susceptibility to the many different possible injuries to the shoulder, the SICK scapula needs to be recognized and addressed. Ideally, an athletic trainer or sports medicine physician should assess the strength, flexibility and alignment of overhead athletes to identify those who would benefit from specific training. If the front of the shoulder is tight, then the scapula will be pulled forward, thereby compromising proper alignment of the articular surfaces of the shoulder joint.
Some athletes become so focused on the muscles that they can see in the mirror that they forget about the muscles in the back, which also need to be strengthened. Having muscle balance between the front and the back facilitates maintenance of optimal shoulder joint positioning and movement patterns.
To address the needs of an athlete with a SICK scapula, the first step is to recognize the existence of the problem. The next step is to initiate a proper rehabilitation program. There needs to be a balance of strength and flexibility between the front and the back of the shoulder. In the July/August Sports Medicine Spotlight, a detailed description of beneficial exercises will be provided.
1. Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology part III: the SICK scapula, scapular dyskinesis, the kinetic chain and rehabilitation. J Arthro Relat Surg. 2003;19:641-661.
2. Kibler WB, Sciascia A, Wilkes T. Scapular dyskinesis and its relation to shoulder injury. J Am Acad Orthop Surg. 2012:20:364-372.