Is Assessing Scapular Function Worthwhile?

(7 minute-read)

Introduction (what is current practice?)

Clinicians and researchers have been working hard, for a long time, to find tests and devices that can objectively measure scapular position and scapular control for patients with shoulder pathologies.  To list a few, the Palpation Meter (PALM),  3D scapular Joint Position Sense, the modified digital inclinometer, the Lateral Scapular Slide Test, the Scapulometer, the use of load cells to measure protraction strength…and rest assured, the list goes on…

So why is it that many clinicians have chosen to forgo the aforementioned list of complex scapular assessment gizmos and tricks? Well, to begin with many of these instruments have been studied to assess validity and reliability and have been found wanting (An et al. 2021; Shadmehr et al. 2010). Secondly, they are completely impractical for clinical use due to expense, complexity, and general lack of availability.

Still, in current practice it’s not uncommon to find simple objective scapular assessments used in the clinic including 3-point palpation and symptom altering tests, which are special tests for a diagnosis of scapular dyskinesis.

These assessment tools are still in practice because we believe a hypothesis that Scapular Dyskinesis significantly influences shoulder complaints like pain and dysfunction. In reality (evidence informed reality, that is), the relationship between scapular dyskinesis and shoulder complaints is unclear, and it seems plausible that in some cases, atypical postures and movement patterns may be adaptive for a client’s activities of choice (see a thoughtful discussion in D’hondt et al. 2020). Additionally, if our initial hypothesis that scapular dyskinesis drives shoulder complaints was true, why is it then that rehabilitation protocols not focused on scapular dyskinesis seem to show similar effectiveness to treatment programs that do (Bury et al. 2016, Hotta et al. 2020)?

A further critique in the treatment of scapular dyskinesis as an end in itself is that the concept is poorly operationalized and prone to misinterpretation (D’hondt et al 2017; D’hondt et al. 2020). In other words, what exactly is scapular dyskinesis? Is there consensus on its definition? The short answer is no. Another, longer answer might be given by a sample of suggested definitions. Here are a few:

• Scapular position at rest in the frontal plane, sagittal plane, and transverse plane. In other words, up-rotation, elevation/depression, protraction, tilt and winging at rest and in various positions of thoracohumeral elevation or scapular pro/retraction.
• Defined as the abnormal outcome of special tests, also known as “symptom altering tests” which include the lateral scapular slide test, or scapular retraction test.
• Other “loose” definitions like “altered rest position and dysfunctional motion of the scapula” (Teixiera et al. 2021), or “altered scapular positioning and motion” (Kibler et al. 2012) do little to describe specific measurable outcomes.

There seems to be no gold standard to define the problem which presents obvious issues in treating it. With all of this in mind, one might wonder if there’s a true diagnostic value to these tests.
If not useful as a formal diagnosis, might assessments of scapular dyskinesia have some prognostic value? Perhaps scapular positioning might provide some general insight toward the long-term outcome of some shoulder presentations. Alternatively, there might be some predictive value of these assessments if they can guide our treatment of choice: scapular exercise approach versus a general shoulder strength exercise approach versus a combination.

In other words, the prognostic or predictive function of assessments for scapular dyskinesia may be more clinically valuable than their diagnostic function. But of course, further research is required before making strong statements of this sort.

For assessing patient status and change? Why not stick to our true and tested functional outcome measures for shoulder pathologies, like the SPADI or DASH. Those whose psychometric properties are well established… Now that’s an approach sound clinicians can get on board with!

Clinical Take Home

It seems that physiotherapists have a clinical problem to solve. How can we use a loosely defined outcome like scapular dyskinesis, something we may not be able to reliably assess, and which may not be associated at all with patient complaints, and at the same time prescribe a treatment designed to deliver an “improvement” to such an outcome?

We suggest (and the evidence suggests) that scapular dyskinesis need not be resolved for improvements to be realized in shoulder pain and function. And to reiterate, non-dyskinesis focused rehabilitation protocols seem to show similar effectiveness to treatment programs that target scapular dyskinesis.

This is not to say that the evidence for general strength training protocols of the shoulder girdle is informed by rigorously conducted trials in a way that scapular position and control protocols are not. Indeed, a recent editorial in the JOSPT (Powel & Lewis 2021) suggests that the idea that shoulder patients “just need to get stronger” may, in the future, suffer a similar crisis of credibility under the scrutiny of repeated and well conducted studies. Still, as we all know, exercise is a multidimensional treatment that may intervene across dimensions of a biopsychosocial model (self-efficacy, quality-of-life, and also physiological markers), so we should not dispense with exercise protocols.

We would do well, though, to improve our understanding of what we prescribe and why, as the foundations of our treatments seem to be questionable (as has been argued here).

If we believe that scapular dyskinesis is a useful construct, further research is needed at this point to first, develop reliable and valid scapular assessment, second, to validate this assessment as a valid proxy for shoulder complaints, and third to develop interventions that modify the assessment outcomes (and complaints).

We should further be careful about how we talk with clients regarding scapular position and movement. We need to avoid language that places scapular positioning over modification of complaints as the goal of treatment. It may be that variations due to diversity in anatomy or movement patterning are completely acceptable in the context of a specific individual and their activity of choice.

Perhaps over time, increased validity of scapular assessment and an improvement in our ability to credibly attach this construct to actual shoulder complaints will modify the skepticism of the scapular dyskinesis framework we describe here. But that time is not now, and there is a lot of work to be done before we get there.

Authored by James Braithwaite (james@yorkvillephysiotherapy.com)

Reviewed by Lindsay Thompson (lindsay@repphysio.ca), Yara Harb (yaraharb@gmail.com), Erdem Huner (huner@andrews.edu) and Lenerdene Levesque (ktmanager@orthodiv.org)

For further insight on this topic make sure to check out the podcast below where James Braithwaite, Erdem Huner and Jackie Sadie discuss scapular assessment and so much more!

Watch Now

Sources
An DI, Park JE, Lee CH, & Kim SY. (2021). Reliability of scapular upward rotation and anterior-posterior tilt measurements using a modified digital inclinometer in patients with subacromial impingement syndrome. J Back Musculoskelet Rehabil, 34(5):837-843.

Bury J, West M, Chamorro-Moriana G, & Littlewood C. (2016). Effectiveness of scapula-focused approaches in patients with rotator cuff related shoulder pain: a systematic review and meta-analysis. Manual therapy, 25, 35-42.

D’hondt NE, Pool JJ, Kiers H, Terwee CB, & Veeger HE J. (2020). Validity of Clinical Measurement Instruments Assessing Scapular Function: Insufficient Evidence to Recommend Any Instrument for Assessing Scapular Posture, Movement, and Dysfunction—A Systematic Review. Journal of orthopaedic & sports physical therapy, 50(11), 632-641.

D’hondt NE, Kiers H, Pool J J, Hacquebord ST, Terwee CB, & Veeger D. (2017). Reliability of performance-based clinical measurements to assess shoulder girdle kinematics and positioning: Systematic review. Physical therapy, 97(1), 124-144.

Hotta GH, de Assis Couto AG, Cools AM, McQuade KJ, & de Oliveira AS. (2020). Effects of adding scapular stabilization exercises to a periscapular strengthening exercise program in patients with subacromial pain syndrome: A randomized controlled trial. Musculoskeletal Science and Practice, 49, 102171.

Kibler BW, Sciascia A, & Wilkes T. (2012). Scapular dyskinesis and its relation to shoulder injury. JAAOS-Journal of the American academy of orthopaedic surgeons, 20(6), 364-372.

Larsen CM, Søgaard K, Eshoj H, Ingwersen K, & Juul-Kristensen B. (2019). Clinical assessment methods for scapular position and function. An inter-rater reliability study. Physiotherapy theory and practice.

Powell JK, & Lewis JS. (2021). Rotator Cuff–Related Shoulder Pain: Is It Time to Reframe the Advice, “You Need to Strengthen Your Shoulder”?. Journal of orthopaedic & sports physical therapy, 51(4), 156-158.

Shadmehr A, Bagheri H, Ansari NN, Sarafraz H. (2010). The reliability measurements of lateral scapular slide test at three different degrees of shoulder joint abduction. Br J Sports Med. 44(4):289-93.

Teixeira DC, Alves L, Gutierres M. (2021). The role of scapular dyskinesis on rotator cuff tears: a narrative review of the current knowledge. EFORT Open Reviews, 6, 932-940. https://dx.doi.org/10.1302/2058-5241.6.210043