Introduction[edit | edit source]
Scapular dyskinesia (SD) is a term that describes a physical impairment in which the scapula's position and motion are altered. The words dyskinesia or dysrhythmia are often used instead of dyskinesia.  One of the other terms used for SD is scapular winging, but it is a different condition that results in scapular dyskinesia usually after a long thoracic or spinal accessory nerve injury. 
SD can be seen in overhead athletes or patients with shoulder pathology such as rotator cuff disease, glenohumeral instability, impingement syndrome, and labral tears as well as in healthy people.  
Scapular Biomechanics[edit | edit source]
The movement of the scapula can be divided into 3 motions and 2 translations.
The motions are:
- Upward/downward rotation
- Internal/ external rotation
- Anterior/posterior tilt
The translations are:
- Upward/downward sliding on the thorax
- Medial/lateral sliding around the curvature of the thorax
Common patterns of the scapula are called scapular retraction (external rotation, posterior tilt, upward rotation and medial translation), protraction (internal rotation, anterior tilt, downward rotation and lateral translation), and shrug (upward translation, anterior tilt, and internal rotation). 
During the normal overhead upper extremity elevation with internal/external rotation being minimal until 100°, primary scapular movement is upward rotation and secondary scapular movement is posterior tilt. 
The coordinated movement between the scapula and humerus which is necessary for efficient arm movement is termed scapulohumeral rhythm.  An early study  found an overall ratio of 2:1 between glenohumeral elevation and scapular upward rotation. Another study  found that during the scapular plane elevation of the arm, there was a consistent pattern of scapular upward rotation, posterior tilting, and external rotation along with clavicular elevation and retraction.
The altered mechanics in SD are increased scapular anterior tilt, increased scapular internal rotation, and altered scapular upward rotation. 
Etiology[edit | edit source]
The causes of SD are many, but they can be looked at in these three groups:
- Posture-related. 
1. Shoulder-related: Shoulder pathologies associated with SD (acromioclavicular instability, shoulder impingement, rotator cuff injuries, glenoid labrum injuries, clavicle fractures ), inflexibility of the pectoralis minor and short head of the biceps, and stiffness of the posterior glenohumeral capsule can be counted for this group. 
2. Neck-related: Mechanical neck pain syndromes and cervical nerve root-related syndromes. 
3. Posture-related: Excessive thoracic kyphosis and cervical lordosis, which are the changes that athletes are more tend to show are related causes of SD. 
Clinical Presentation[edit | edit source]
- Anterior shoulder pain
- Posterosuperior scapular pain (may radiate into the ipsilateral para spinous cervical region or radicular/thoracic outlet-type symptoms in the affected upper extremity can be found)
- Superior shoulder pain
- Proximal lateral arm pain
Clinical Examination[edit | edit source]
There is no standard clinical assessment of SD. However, some assessment methods have proven to be reliable: 
Determining The Presence or Absence of Dyskinesia[edit | edit source]
- Type 1: Inferior angle prominence,
- Type 2: Medial border prominence,
- Type 3: Excessive superior border elevation,
- Type 4: Absence of SD, symmetric scapular motion.
Manually Assisted Movements of Scapula[edit | edit source]
To determine the role of the scapula position in shoulder pain two tests that apply manual assistance to the scapula are The Scapular Assistance Test (SAT) and The Scapular Reposition (Retraction) Test (SRT). 
In the SAT, the patient is asked to do arm flexion and rate the pain on the numerical pain rating scale. The same process is repeated while the examiner pushes upward and laterally on the inferior angle, and pulls the superior aspect of the scapula (to produce posterior tilt). If two or more points of pain decrease after assisted movement, the test is positive. 
In SRT, the patient is asked to do 90 degrees of flexion with shoulder internal rotation while the examiner stabilizes the medial scapular border with one hand. Then the patient is asked to hold the position while the examiner is applying resistance with the other hand. If the pain felt by the patient is decreased or the strength is increased with the assistance the test is positive.  This test is described by Kibler et al  to establish the scapular retraction stabilization on the improvement of supraspinatus strength deficits in patients with SD. 
Assessment of Surrounding Structures[edit | edit source]
The structures around the scapula can be assessed for pain, loss of function, soft tissue laxity and muscle power. 
The sternoclavicular (SC) and acromioclavicular (AC) joints should be assessed for instability. AC joint can be assessed for anterior-posterior (AP) laxity by mobilizing the acromion in an AP direction while stabilizing the clavicle.  Manual muscle tests for rotator cuff/biceps muscles can be applied. The infraspinatus strength test shows good reliability to assess infraspinatus weakness due to SD. 
Muscle Tests[edit | edit source]
Three specific muscle tests that the clinician observes the scapula position and considers the scapular muscle weakness if the break in the position and scapular movement occurs are: 
- Manual resistance of the arm at 130° of flexion (for the serratus anterior) 
- Manual resistance of the arm at 130-150° of abduction (for the lower and middle trapezius) 
- Extension of the arm at the side (for the rhomboid) 
Core Evaluation[edit | edit source]
With the low row test, if core and hip strength facilitate the scapular motion can be assessed. The examiner stands behind the patient. The patient is asked to do slight arm extension and resist the movement of the arm into flexion. The same movement is repeated with gluteal muscle contraction. If the strength increase with gluteal contraction core/lower extremity strengthening can be added to the treatment plan. 
Outcome Measures[edit | edit source]
Physiotherapy Management[edit | edit source]
Treatment of SD aims at the restoration of scapular retraction, posterior tilt and external rotation. Specific exercises for scapular rehabilitation are :
Flexibility exercises: To increase the flexibility of the pectoralis minor and the external rotation and posterior tilt of the scapula, shoulder horizontal abduction at 90 degrees and 150 degrees of elevation. 
Stabilization exercises based on stretching and strengthening to optimize scapular kinematics, and improve muscle strength and joint position sense   : Closed and open kinetic chain exercises, including push-ups, lawnmower exercises, and resisted scapular retraction.  
The serratus anterior and trapezius muscles play a key role in scapular stabilisation. They act as a force couple during upper extremity movements and are particularly important in the overhead position.   Also, they are the main muscles that cause dyskinesia,  so they should be considered well in rehabilitation.
The push-ups on a stable surface stretch the serratus anterior and improve the general muscle strength with a Red Cord sling. The push-ups on an unstable surface increase the trapezius activation while decreasing the serratus anterior activation. 
Shrug exercises activate the upper and lower trapezius and increase the upward rotation angle. So they are useful for the patient with SD and corresponding scapular downward rotation syndrome.  But, this exercise should not be in the first 4-6 weeks of rehabilitation, or it can delay the restoration of scapular muscle balance. 
A review article about the effects of Kinesio taping  concluded that Kinesio taping over the upper and lower trapezius could improve the scapular muscle balance and increase the upward scapular rotation in patients with type 2 SD. 
Presentations[edit | edit source]
|Advanced Exercises for the Upper Quarter: A How To Guide for Scapular Motor Control Rehabilitation
This presentation, created by Stephanie Pascoe as part of the OMPT Fellowship in 2010, describes a how to guide for scapulothoracic rehabilitation. It includes some great animations!
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