What Is Scapular Dyskinesis?

Scapular dyskinesis describes any observable abnormality of scapular position or motion during arm elevation and return. The most common patterns are inferior angle prominence (Type I, driven by pectoralis minor tightness and serratus anterior weakness), medial border prominence or winging (Type II, driven by serratus anterior or lower trapezius weakness), and superior translation or early shoulder shrugging (Type III, driven by upper trapezius dominance). These patterns reduce subacromial space, impair rotator cuff mechanics, and increase glenohumeral joint loading — the biomechanical basis for the causal relationship between scapular dyskinesis and shoulder pain that epidemiological research consistently supports.

The three contributing factors to scapular dyskinesis are: muscle weakness or inhibition (primarily serratus anterior and lower trapezius), thoracic stiffness (kyphosis and rotation restriction change the scapular resting position and movement plane), and soft tissue tightness (pectoralis minor tightening produces inferior angle prominence and restricts posterior tilting). Effective rehabilitation must address all three simultaneously.

The Rehabilitation Framework

Step 1 — Manual therapy first: Thoracic extension mobilisation, pectoralis minor release, and subcoracoid soft tissue work create the structural conditions in which exercise can be effective. Attempting serratus anterior activation in a patient with severe thoracic kyphosis is mechanically inefficient — the scapula sits on a surface that prevents the upward rotation and posterior tilt that serratus activation is trying to produce.

Step 2 — Isolate weak muscles: Serratus anterior (wall push-up plus, serratus punch) and lower trapezius (prone Y, prone T, wall slide with depression) isolation exercises establish the motor pattern before loading. These exercises use low resistance but high repetition to build the motor engram.

Step 3 — Integrate under load: Once individual muscle activation is established, integrate the pattern into compound movements. The set-up for every pressing, pulling, and overhead exercise should include deliberate scapular retraction and depression before the glenohumeral movement begins. This teaches the scapular stabilisers to fire appropriately within functional movement.

The scapular assistance test (SAT) in rehabilitation: The SAT — the clinician manually assisting scapular upward rotation and posterior tilt while the patient elevates the arm — does more than diagnose scapular contribution to shoulder pain. When performed during exercise (the clinician assists scapular kinematics while the patient practices the elevation movement), it teaches the patient what optimal scapular position feels like and provides the neural template for their active training. Patients who have the SAT performed during early rehabilitation demonstrate better scapular motor learning than those who perform unsupported exercises alone.

References & Further Reading

  1. Kibler WB, et al. Clinical implications of scapular dyskinesis in shoulder injury. Br J Sports Med. 2013;47(14):877–885.
  2. Cools AM, et al. Rehabilitation of scapular muscle balance. Am J Sports Med. 2007;35(10):1744–1751.
  3. Ludewig PM, Reynolds JF. The association of scapular kinematics and glenohumeral joint pathologies. J Orthop Sports Phys Ther. 2009;39(2):90–104.