Scapular Winging
Anatomy:
Scapulothoracic Joint1
Movement2:
Image from https://www.earthslab.com/wp-content/uploads/2017/06/060717_0239_Movementsof1.jpg
Definitions:Of note, the scapula aids with shoulder abduction in the following way3:
Scapular dyskinesis2: deviation in normal resting position of the scapula during shoulder movement.
Medial winging4: On exam, the inferior medial scapula elevates and protrudes posteriorly and medially (see figure 2). This can be caused by an injury to the serratus anterior muscle or to the long thoracic nerve.
Figure 2 – Medial winging right shoulder
Image from https://www.orthobullets.com/shoulder-and-elbow/3062/scapular-winging
Lateral winging4: On exam, the superior medial scapula drops downward and protrudes posterior and lateral (see figure 3). This can be due to a deficit in the trapezius muscle as a result of injury to the spinal accessory nerve.
Figure 3 – Lateral winging right shoulder
Image from https://www.orthobullets.com/shoulder-and-elbow/3062/scapular-winging
Differential Diagnosis5:
Neurogenic:
Muscular:
Bone:
Other:
Scapular Exam:
Note: The differential diagnosis for scapular winging is broad and a complete shoulder examination should be completed along with the following scapular exam.
Inspection:
Inspect scapulae bilaterally for symmetry, atrophy, and for evidence of medial or lateral winging (see above for descriptions). At this stage, check for crepitation of the superior medial scapula during passive range of motion.
Step 1: Assessing for scapular dyskinesia
The Kibler classification6 can be used by asking the patient to abduct and adduct the shoulder (rate of 45 degrees/second) and watching their scapular motion:
The classification is as follows:
Type 1: At rest: Inferior medial border prominent dorsally
During motion: inferior angle tilts dorsally and the acromion tilts ventrally over the top of the thorax
Type 2: At rest: Entire medial border is prominent dorsally
During motion: Medial border tilts dorsally off the thorax
Type 3: At rest: Superior border elevated and the scapula is anteriorly displaced
During motion: Shoulder shrug initiates movement without winging of the scapula
Type 4: Symmetric scapulothoracic movement
Figure 4 – Kibler Classification
Image from Kibler WB et al.Qualitative clinical evaluation of scapular dysfunction: a reliability study. J Shoulder Elbow Surg.2002;11:550-556.
Note: Intra-rater and inter-rater reliability for this test are k = 0.5 and k = 0.4 respectively, and as such, clinical utility is lower than for the tests below.5
Lateral Scapular Slide Test (LSST)7:
This test is an objective measure for shoulder dyskinesia.
How to perform: measure side to side difference of the distance from the inferior angle of the scapula to the adjacent spinous process in 3 different positions (shown below). A side to side difference of >1.5cm is considered pathological.
Figure 5 – Three positions of LSST
Image from Curtis, Thomas, and James R. Roush. “The lateral scapular slide test: A reliability study of males with and without shoulder pathology.” North American journal of sports physical therapy: NAJSPT 1.3 (2006): 140.
Scapular Dyskinesis Test (SDT)8:
How to perform: Patient is given 2 dumbbells of 3lbs each (if patient weighs 150lb or less) or 5lbs (if patient weighs over 150lb). Patient does bilateral flexion and bilateral abduction 5 times each. Make sure shoulders are in thumbs up position during both flexion and abduction. Test is positive if winging or dysrhythmia is present on observation.
Inter-Rater Reliability ranges from 0.48-0.61.
Figure 6 – Scapular dyskinesis test
Image from McClure, Philip, et al. “A clinical method for identifying scapular dyskinesis, part 1: reliability.” Journal of athletic training 44.2 (2009): 160-164.
The limitations with the LSST and SDT tests is that the prevalence of scapular dyskinesia can be 33% in asymptomatic non-overhead athletes and 61% in asymptomatic overhead athletes. While they are useful in determining if there is scapular dyskinesia, the Scapular Assistance Test and Scapular Reposition Test (below) can be used to determine if scapular dyskinesia is contributing to symptoms.9
Step 2: Assessing if scapular dyskinesia is contributing to patient symptoms
Scapular Assistance Test (SAT)10:
How to perform: Fixate clavicle and scapular spine with one hand and place other hand inferior angle of the scapula with other hand (as shown below). Ask patient to abduct the shoulder and assist the scapular movement (upward rotation of scapula). A positive test is if the patient has decreased pain during abduction.
Figure 7 – Scapular assist test
Image from McClure, Philip, Elliot Greenberg, and Stephen Kareha. “Evaluation and management of scapular dysfunction.” Sports medicine and arthroscopy review 20.1 (2012): 39-48.
Scapular Retraction (Rotation) Test (SRT)10:
How to perform: Fixate clavicle and scapular spine with one hand and with the forearm of the same hand, press the patient’s scapula against the chest wall. Now perform the empty can test. A positive test is if the patient has decreased pain during empty can testing.
A positive test on either the SAT or SRT indicates weakness of the scapular stabilizers including the lower trapezius and the serratus anterior.
Figure 8 – Scapular Retraction Test
Image from McClure, Philip, Elliot Greenberg, and Stephen Kareha. “Evaluation and management of scapular dysfunction.” Sports medicine and arthroscopy review 20.1 (2012): 39-48.
Step 3: Scapular neurological exam to assess for nerve entrapments11
Long Thoracic Nerve
If the patient has medial winging, perform testing for the long thoracic nerve. Ask the patient to perform a push-up movement against the wall. Displacement of the scapula medially and superiorly (medial winging) that is more pronounced with this maneuver is consistent with long thoracic nerve entrapment.
Spinal Accessory Nerve
If the patient has lateral winging, ask the patient to abduct or externally rotate their arm against resistance. In patients with spinal accessory nerve entrapment, the superior angle of their scapula will be displaced laterally with this movement. Alternatively, lateral winging can be appreciated on descent from full abduction on the affected side.
Dorsal Scapular Nerve
In patients with lateral winging, assess the dorsal scapular nerve. Ask the patient to flex their shoulder to 180 degrees. Now ask the patient to slowly extend their shoulder and examine the scapula during this motion. A positive test for nerve entrapment is if the inferior angle of the scapula becomes more laterally displaced on the affected side (lateral winging).
Imaging/Investigations5:
Scapular winging is a clinical diagnosis. Investigations can be done to identify the etiology of winging.
Initial workup can include the following (based on differential):
Management:
Medial Winging
Conservative Management Principles5
Operative Management12
Lateral winging
Conservative Management Principles5
Surgical Management12
Author Dr. Mustafa Mohamedali (May 9, 2020 PR AF)
References
Images
Figure 1: https://www.earthslab.com/wp-content/uploads/2017/06/060717_0239_Movementsof1.jpg
Figure 2 + 3: https://www.orthobullets.com/shoulder-and-elbow/3062/scapular-winging
Figure 4: Kibler WB et al.Qualitative clinical evaluation of scapular dysfunction: a reliability study. J Shoulder Elbow Surg.2002;11:550-556.
Figure 5: Curtis, Thomas, and James R. Roush. “The lateral scapular slide test: A reliability study of males with and without shoulder pathology.” North American journal of sports physical therapy: NAJSPT 1.3 (2006): 140.
Figure 6: McClure, Philip, et al. “A clinical method for identifying scapular dyskinesis, part 1: reliability.” Journal of athletic training 44.2 (2009): 160-164.
Figure 7 + 8 McClure, Philip, Elliot Greenberg, and Stephen Kareha. “Evaluation and management of scapular dysfunction.” Sports medicine and arthroscopy review 20.1 (2012): 39-48.