Shoulder impingement syndrome : Contribution of scapula

The shoulder is a ball and socket synovial joint . The shoulder is such a fascinating joint with 180 degrees of freedom, which relies on excellent dynamic movement.

How should we use it in the diagnosis of shoulder pain?

In early 1980, Neer et all describes Shoulder impingement and researched for many years and some of the original work . As our understanding of impingement has expanded we have come to realise that there are types of shoulder impingement i.e internal and external, and primary and secondary (Ludewig & Braman, 2011).

What is Internal versus external impingement?

It depends on the site of the impingement. If it is located in the subacromial space it is known as external impingement. If it is located within the glenohumeral joint it is known as internal impingement (Cools, Cambier & Witvrouw, 2008).

External impingement : According to Neer et all, when there is compression between the rotator cuff tendons or long head of bicep tendons, between the humeral head and the undersurface of the acromion, coracoacromial ligament .

Internal impingement : compression of the supraspinatus tendon and/or infraspinatus tendon between the humeral head and posterosuperior glenoid rim. This usually occurs at 90 degrees abduction and external rotation.

Remember , when you simply saying “shoulder impingement” as a diagnosis. This label does not indicate you:
• Which structures are involved.
• Where is the exact site of impingement

What is Primary and secondary impingement?

When there is injury to shoulder joint, it gradually leads to structural narrowing of the subacromial space due to acromioclavicular athropathy, or pathology within the tissues in the subacromial space .

According to Lewis (2011) et all, many people directly jump to the assumption that if structures are impinged, surgery is required to ‘make more room’, but it’s not the case. The pathology lies within tendon itself.

Secondary impingement :

• Glenohumeral joint instability, which can lead to excessive humeral head translation and/or poor position of the humerus in relation to the scapula. In addition to that subscapularis inefficiency to maintaining huneral head in central position.

• Scapula dyskinesis

• GIRD (glenohumeral internal rotation deficit) There is a loss of glenohumeral internal rotation and increase in external rotation, often the posterior cuff & capsule become tight and there is excessive anterior translation of the humeral head resulting in secondary impingement also we can say it’s shoulder medial rotation uncontrol movement. ( Lewis2011 et all)

Many authors said that secondary impingement can affect the rotator cuff tendons or long head of biceps, and it can be both internal and external (Burkhart, Morgan & Kibler 2003; Cools, Cambier & Witvrouw, 2008; Ludewig & Braman, 2011).

ASSESSMENT OF THE SHOULDER COMPLEX:

The knee movement occurs in sagittal plane only which we consider 1) flexion and 2) extension. Shoulder is complex joint and it has many range of motion which are even more complex.

When we see shoulder patient walk into our clinic , First question comes in our mind where to start assesment. The key to improving your assessment of shoulders is to have a routine checklist in your assessment technique. For instance you should always assess the injured then the non-injured side. According to chief complaint make order of your test because if you prove ke pain initially then all test will be false positive . You should always assess movements in the same order.

Cools et al (2008) published a fantastic paper outlining an assessment algorithm to assist clinicians in their screening of shoulder patients with suspected impingement and clinical diagnosis. This algorithm is a great place to start when you’re developing skills in shoulder assessment.

The images below represent the Hawkin’s Kennedy, Neer, and Jobe test for shoulder impingement described in the algorithm above (Cleland, 2005).

after reading this algorithm the scapula assistance test & scapula retraction test will become your routine clinical test

(Cools, Cambier & Witvrouw 2008)

Scapula assistance test : assesses the impact of correcting scapula position on shoulder pain and impingement symptoms during active shoulder elevation. the clinician assists the scapula into upward rotation while the patient elevates their arm and observes if there is a change in pain.

Scapula retraction test assesses the impact of maintaining scapula position during loading and assessing the impact on pain. For the scapula resistance test the therapist resists the scapula into retraction while assessment pain in the resisted elevation in an abducted and internally rotated position.

Let’s gather all points :

When assessing a shoulder you should always try to focus on the following:

• Carefully observing the functional aggravating position.
• Reproducing shoulder symptoms and then trying to change them with scapula positioning, muscle activation exercises or manual therapy.

• If there is a reduction in pain it indicates a ‘green light’ to go ahead and treat with same rehabilitation.

• If there is Red light during your assessment – you will need to reconsider your diagnosis, consider a referral for medical imaging and/or referral to a specialist.

References:

1. Braman, J. P., Zhao, K. D., Lawrence, R. L., Harrison, A. K., & Ludewig, P. M. (2014). Shoulder impingement revisited: evolution of diagnostic understanding in orthopedic surgery and physical therapy. Medical & biological engineering & computing, 52(3), 211-219.

2) Cools, A. M., Cambier, D., & Witvrouw, E. E. (2008). Screening the athlete’s shoulder for impingement symptoms: a clinical reasoning algorithm for early detection of shoulder pathology. British journal of sports medicine, 42(8), 628-635.

3)Cools, A. M., Declercq, G., Cagnie, B., Cambier, D., & Witvrouw, E. (2008). Internal impingement in the tennis player: rehabilitation guidelines. British journal of sports medicine, 42(3), 165-171.

4) Kibler, W. B., & McMullen, J. (2003). Scapular dyskinesis and its relation to shoulder pain. Journal of the American Academy of Orthopaedic Surgeons,11(2), 142-151.

5) Kibler, W. B., Ludewig, P. M., McClure, P. W., Michener, L. A., Bak, K., Sciascia, A. D., … & Cote, M. (2013). Clinical implications of scapular dyskinesis in shoulder injury: the 2013 consensus statement from the ‘scapular summit’. British journal of sports medicine, bjsports-2013.

6) Kibler, W. B., Sciascia, A. D., Bak, K., Ebaugh, D., Ludewig, P., Kuhn, J., … & Cote, M. (2013). Introduction to the second international conference on scapular dyskinesis in shoulder injury—the ‘Scapular summit’report of 2013.British journal of sports medicine, bjsports-2013.

7) Ludewig, P. M., & Braman, J. P. (2011). Shoulder impingement: biomechanical considerations in rehabilitation. Manual therapy, 16(1), 33-39.