Scapular Dyskinesis: Biomechanics, Evaluation and Treatment

Typical movement of the scapula occurs in the sagittal, coronal, and transverse planes. The primary movements consist of two translations: superior/inferior, and protraction/ retraction, as well as three rotations: upward/downward, internal/external, and anterior/posterior. 

Scapular Dyskinesis


Upward rotation is primary and posterior tilt secondary during normal overhead UE elevation with internal/external rotation being minimal until 100°. 

Burkhart et al has used the acronym SICK to refer to the syndrome associated with scapular dyskinesia. “SICK” Scapula Syndrome refers to Scapular Malpositioning, Inferior medial border prominence, Coracoid pain and malposition and DysKinesis of scapular movement. 

It’s an overuse Syndrome. The scapula is protracted and is in anteriorly tilted position secondary to tight pec minor or short head of the biceps at the insertion to the coracoid process. 

Coracoid tenderness is an important sign of scapular dysfunction, which is secondary to constant traction from tightness at the tendon’s insertion.

 Dysrhythmia is defined as early or excessive scapular elevation or shrugging on arm elevation and/or a rapid downward rotation during arm lowering, or a non-smooth or stuttering motion during these actions.

Clinical Presentation

Overhead athletes have higher prevalence of scapular dyskinesia of about 61% as compared with non-overhead athletes.

Symptoms of isolated SICK scapula: anterior shoulder pain (most common), posterior superior scapular pain, superior shoulder pain, proximal lateral arm pain or any combination of above. 

Posterosuperior scapular pain may radiate into the ipsilateral paraspinous cervical region or patient may complain of radicular/TOS type symptoms. The onset is almost always insidious.

Kibler classification of scapular dysfunction

Type I or Inferior dysfunction.  

The primary external visual feature is the prominence of the inferior angle as a result of anterior tilting of the scapula in the sagittal plane. Inferior pattern presentation is better visualised while in the hands-on-hips position or during eccentric lowering from overhead elevation. According to Kibler, Type 1 pattern is most commonly found in patients with rotator cuff dysfunction.

Type 2 or Medial dysfunction 

The primary external visual feature is the prominence of the entire medial scapular border due to internal rotation of the scapula in the transverse plane. As with Type 1, the Type 2 presentation becomes more evident in the hands-on-hips position and during active eccentric lowering from overhead. Medial pattern dysfunction most often occurs in patients with glenohumeral joint instability.

Type 3 or Superior dysfunction  

Characterised by excessive and early elevation of the scapula during UE elevation. This pattern has been referred to as compensatory shoulder hiking or shrug and is most often seen in patients with rotator cuff dysfunction and deltoid-rotator cuff force couple imbalances.

Diagnostic Procedures

Current tests and measures, while proven to be reliable, have not altogether shown strong validity by demonstrating correlation with biomechanical motion, symptoms, pathology, or outcomes.

Recommendations for appropriate clinical measures include:

Clinical observation of scapular dyskinesis

Kibler classification of dysfunction Type 1, 2, or 3 or Scapular Dyskinesis Test (SDT) recommended by McClure et al.  It is recommended that several repeated bouts of arm elevation be observed to assess the affects of fatigue on scapular stabilization.

Symptom altering tests

Scapular retraction test'.[10]Baseline AROM and pain is evaluated.  This test is positive if pain is reduced as the therapist assists active elevation by applying a posterior tilt and external rotation motion to the scapula. This application may be used in conjunction with other tests such as Neer's, Hawkin's-Kennedy, and Jobe's relocation.

Scapular assistance test

Baseline AROM and pain is evaluated.  The therapist then applies an assist to scapular dynamics.  This test is positive if ROM is increased or pain is reduced as the therapist manually assists scapular upward rotation during active UE elevation.  

Lateral scapular Slide test (LSST)  

Measurements are taken from spine of scapulae to T2/T3, Inferior angle of scapulae to T7/T9 and superior angle of scapulae to T2. The measurements are taken in 3 positions, (A) sitting/standing with arms resting on the side, (B) Hands on the waist, Thumbs Posteriorly (45 abduction), (C) 90 degrees abduction and maximal internal rotation. Measurement should not vary more than 1 to 1.5 cm, more the 1.5 cm difference significant.

Isometric Scapular Pinch test 

Patient in standing position and is asked to actively squeeze or retract the scapulae together as hard as possible. Normal Response: An individual able to hold the squeeze or 15 to 20 sec without any burning pain or noticeable weakness. Positive: Burning pain present. Watch for: patient relaxing the contraction.

Scapular Load test: As in position for LSST, Manual load is applied in anterior, posterior, inferior or superior direction to the arm, and scapula should not move more than 1.5 cm.

Wall pushup test 

Patient performs wall pushups for 15 to 20 times. Weakness of scapular muscles (mainly serratus anterior) or winging usually shows up with 5 to 10 pushups. For stronger or younger population, perform the test on floor.

Manual muscle testing

MMT for the middle and lower trapezius, and serratus anterior.

Pectoralis minor muscle tightness

Current measures examine mm length at resting positions, not at maximal length.  Unfortunately, there are no validated clinical measures to identify a patient as having a tight pectoralis minor muscle.   

Static Measurements

Static measurements consists infera: difference in vertical height of the superomedial scapular angle of the dropped scapula compared to contralateral angle.  

Lateral displacement: difference of superomedial scapular angle from midline abduction: difference in angular degrees of medial scapular margin from plumb line.


Outcome Measures

DASH

Management / Interventions

Intervention is aimed at reducing posterior capsule and pectoralis minor restriction and restoring periscapular mm balance through exercises promoting early and increased serratus anterior, lower, and middle trapezius activation while minimising upper trapezius activity.

Manual grade 4 mobilization to reduce posterior capsule tension, cross-body stretch.

Manual stretching and soft tissue mobilization to decrease pec minor tension (cadaveric studies imply that a position of 150 degrees elevation with 30 degrees scapular retraction is optimal).

Exercises of sidelying forward flexion, external rotation, prone extension, and prone horizontal abduction to strengthen middle and lower trapezius over upper trapezius.

Quadruped and variable push-up positions to activate serratus anterior.

Rehab Protocol

Phase I

Flexibility

  • Soft tissue Release
  • Tspine Mobility (manual Mobs/Manips)
  • Tspine Extension Ex
  • Pec Stretch
  • Sleeper’s stretch
  • Genie Stretch
  • Upper traps stretch

Isometrics

  • Scapular Pinches
  • Robbery Pinches
  • Low Row Wall isometrics
  • Shoulder ER isometrics
  • Scapular Depressor isometrics

Isotonics

  • Scapular Pinches w/ Theraband
  • Low Row w/ Theraband
  • Shoulder ER/IR in standing
  • Dynamic Hug
  • Scapular punches
  • Cheerleader Exercises.

Phase II

  • Seated Rows
  • High Rows
  • 3Prone Rows
  • Standing Robbery w/ theraband
  • Prone Y, I, T and W
  • Lawnmower/Standing D2 Cocking
  • Side lying ER
  • PNF D1/D2
  • Lats Pull downs
  • 10. Scapular clocks
  • Wall washes
  • Thrower’s 10
  • Manually Resisted scapular strengthening
  • Stretches

Phase III

CKC exercises and advanced exercises.

  • Super 6: Upright Row, Dynamic Hug, Cocking/Decelaration, Cocking/acceleration, B/L D2, B/L pullovers
  • Standing cable column punches
  • Bear crawl on Swiss ball
  • Plyoball Decelaration
  • Seated Pike lift
  • Push Plus/Scapular Pushups
  • Standing Snow Angels
  • Wall ball Scours
  • Stretches

Dr Rohit Bhaskar, Physio
Dr Rohit Bhaskar, Physio Dr. Rohit Bhaskar, Physio is Founder of Bhaskar Health and Physiotherapy and is also a consulting physiotherapist. He completed his Graduation in Physiotherapy from Uttar Pradesh University of Medical Sciences. His clinical interests are in Chest Physiotherapy, stroke rehab, parkinson’s and head injury rehab. Bhaskar Health is dedicated to readers, doctors, physiotherapists, nurses, paramedics, pharmacists and other healthcare professionals. Bhaskar Health audience is the reason I feel so passionate about this project, so thanks for reading and sharing Bhaskar Health.

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