The shoulder is one of the most mobile joints of the body. It allows us to engage in overhead movements that make life easier. However, this comes at a cost. In order for the shoulder to have such a wide range of motion (ROM), it has less stability than most other joints. In fact, shoulder instability is a leading cause of disability and a common reason patients seek care.
Clinical shoulder instability is defined as symptomatic abnormal motion of the ball and socket (glenohumeral) joint. Consider the ROM between loss of motion (hypomobile), normal ROM, increased but pain-free ROM (hypermobile), and complete dislocation. Instability lies between hypermobile and dislocation.
Three classes of shoulder injury:
- Type 1—traumatic with structural pathology
- Type 2—atraumatic with structural pathology
- Type 3—atraumatic with no structural pathology but abnormal muscle pattern (imbalance)
Shoulder instability results from an imbalance or pathology that disturbs one or more of the shoulder stabilizing structures. It can be subdivided into “structural” and “functional.” Structural instability includes injuries: acute (type 1), repetitive microtrauma (multiple small injuries), and congenital (type 2). Functional instability includes abnormal posture, muscle imbalances, altered nervous system conditions, and the like (type 3). The direction of instability can vary depending on the nature of the condition.
For type 1, surgery is usually best, especially in a young, active athlete. However, for some type 2 and most 3 classes of instability, non-surgical care (which includes chiropractic) is preferred. Doctors of chiropractic focus on whole body management, from structural issues to nutrition and wellness. Posture management is a HUGE component of chiropractic care. Poor posture is a VERY common contributor to shoulder instability and dysfunction. Specifically, upper cross syndrome and scapular dyskinesis are present in nearly 90% of patients with functional shoulder instability. The upper cross syndrome includes overactive posterior neck and chest muscles and underactive deep neck flexors and scapular/upper back muscles. Scapular dyskinesis includes slumped, slouchy, or forward head posture. Manual therapy applied to joint restrictions located in the neck, mid-back, and shoulders is routinely performed by chiropractors. Manual therapy is important especially to restore external rotation motion.
For those with non-traumatic posterior instability, the current research suggests that conservative management has an excellent success rate. However, the longer the condition has been present, the more treatment it may take for the patient to achieve a satisfactory result. So, the best advice is to consult with your chiropractor early on when symptoms first present.
