Ludewig and Reynolds review the evidence linking abnormal scapular and clavicular kinematics to six glenohumeral pathologies. The paper synthesizes 11 impingement studies, 5 instability studies, and 4 adhesive capsulitis studies, then maps biomechanical mechanisms and clinical management implications. The core question: which direction of scapular kinematic change is pathological, which is compensatory, and what should you target in rehab?
The direction of scapular kinematic change tells you what is wrong before imaging does. Reduced upward rotation and posterior tilt point toward impingement-type pathology driven by serratus underactivation, pec minor tightness, or kyphosis. Increased upward rotation should raise suspicion for compensated rotator cuff tearing or adhesive capsulitis — two conditions that require very different management.
When you examine a shoulder, assess pectoralis minor resting length, posterior capsule tightness (GIRD), thoracic posture, and scapular muscle strength before defaulting to a generic rotator cuff protocol. These are modifiable risk factors with measurable kinematic consequences, even in asymptomatic patients.
For rehabilitation, serratus anterior is the priority: it is the only scapulothoracic muscle that simultaneously produces upward rotation, posterior tilt, and AC joint external rotation. Push-up plus and supine punch exercises activate serratus with minimal upper trapezius co-activation. Useful when excess clavicular elevation is part of the presentation.
For patients with subacromial impingement, avoid aggressive rhomboid/retraction exercises early in rehab. The rhomboids are scapular downward rotators and can worsen the kinematic deficit you are trying to correct.
Ludewig and Reynolds review the evidence linking abnormal scapular and clavicular kinematics to six glenohumeral pathologies. The paper synthesizes 11 impingement studies, 5 instability studies, and 4 adhesive capsulitis studies, then maps biomechanical mechanisms and clinical management implications. The core question: which direction of scapular kinematic change is pathological, which is compensatory, and what should you target in rehab?
The direction of scapular kinematic change tells you what is wrong before imaging does. Reduced upward rotation and posterior tilt point toward impingement-type pathology driven by serratus underactivation, pec minor tightness, or kyphosis. Increased upward rotation should raise suspicion for compensated rotator cuff tearing or adhesive capsulitis — two conditions that require very different management.
When you examine a shoulder, assess pectoralis minor resting length, posterior capsule tightness (GIRD), thoracic posture, and scapular muscle strength before defaulting to a generic rotator cuff protocol. These are modifiable risk factors with measurable kinematic consequences, even in asymptomatic patients.
For rehabilitation, serratus anterior is the priority: it is the only scapulothoracic muscle that simultaneously produces upward rotation, posterior tilt, and AC joint external rotation. Push-up plus and supine punch exercises activate serratus with minimal upper trapezius co-activation. Useful when excess clavicular elevation is part of the presentation.
For patients with subacromial impingement, avoid aggressive rhomboid/retraction exercises early in rehab. The rhomboids are scapular downward rotators and can worsen the kinematic deficit you are trying to correct.