MOVEMENT IMPAIRMENTS OF THE SCAPULOTHORACIC REGION SCAPULAR DOWNWARD ROTATION SYNDROME

The shoulder is truly an amazing structure. The longer you study the biomechanical components of the upper extremity, the more fascinating it becomes. Truly, the most interesting aspect of the shoulder is the simple fact that what this structure lacks in stability it makes up in mobility. According to Robert A. Donatelli, (1997):

“…the shoulder is capable of moving in over 16,000 positions, which can be differentiated by 1 degree in the normal person.”

This sounds great in theory, but those 16,000 positions of movement are constantly compromised by our tedious activities of daily living that lead to numerous movement impairment syndromes. Sahrmann and Shirley (2002) defined movement impairment syndromes as:

“…localized painful conditions arising from irritation of myofascial, periarticular, or articular tissues. Their origin and perpetuation are the result of mechanical trauma, most often micro trauma.”

It is this constant micro traumatization that leads to some of our most common shoulder pathologies. There are two major categories of movement impairment syndrome of the upper extremity: Movement impairment of the scapulothoracic region and movement impairment of the glenohumeral region. Fig. 1 illustrates a breakdown of each of these two major categories with their corresponding movement impairment syndromes.

MOVEMENT IMPAIRMENTS OF THE SCAPULOTHORACIC REGION	MOVEMENT IMPAIRMENTS OF THE GLENOHUMERAL REGION
Scapular Downward Rotation	Syndrome Humeral Anterior Glide
Scapular Depression Syndrome	Humeral Superior Glide (Abduction)
Scapular Abduction Syndrome	Shoulder Medial Rotation
Scapular Winging Syndrome	Glenohumeral hypomobility

Fig. 1. Classification of Movement Impairment Syndromes in the shoulder joint

In this article we will look at the Scapular Downward Rotation Syndrome (SDRS). SDRS is a terminology used to name multiple shoulder pathologies of the upper extremity. Viewing the whole picture of this syndrome will help practitioners better understand the role SDRS plays in the pathophysiology of the following pathologies (Sahrmann, Shirley, 2002):

* Rotator cuff tendinopathy, impingement and tears, 
* Thoracic outlet and neural entrapment, 
* Humeral subluxation and humeral instabilities,
* Cervical Pain (including or not including radiating pain into the upper extremity), 
* Pain in the levator scapula and upper trapezius muscle, 
* Sternoclavicular joint pain. 

Let us first dissect the terminology of SDRS. The name of this syndrome tells that there is a problem with the downward rotation of the scapula. Fig. 2 illustrates the muscles that are primarily responsible for the downward rotation of the scapula.

DOWNWARD ROTATION OF THE SCAPULA:

Levator Scapula

Rhomboids Major/Minor

Pectoralis Minor

Fig. 2. Main participants in SDRS

However, this is only the beginning. Many times as therapists we forget that our body works as a completely balanced system. If we look at one impaired movement, we should also look at the opposing force, in this case it would be forces, which are responsible for the upward rotation of the scapula. Fig. 3 shows the muscles involved in the upward rotation of the scapula.

UPWARD ROTATION OF THE SCAPULA:

Upper Trapezius

Lower Trapezius

Serratus Anterior

Fig. 3. Muscles responsible for the upward rotation of the scapula

There are two muscle groups that are responsible for upward and downward rotation and they always work like antagonists for the movements but agonists if the scapula needs stabilization (e.g., one types while holding elbow in the air). Any time we treat muscles using manual therapies, we should remember that the musculoskeletal system works in this agonist/antagonist fashion.

Thus, during each movement there is one muscle group that is contracting while an opposing muscle group is relaxing. With that said, if there is dysfunction or shortening of muscles that create the downward rotation, this condition will also affect the upward rotation of the scapula creating an imbalanced scapulohumeral rhythm.

Using the basic concepts of the agonist/antagonist theory we must look at the term force couple. A force couple is defined as two forces of equal magnitude but in opposite direction that produce rotation or stabilization (Frankel and Nordin, 1980). All six muscles mentioned above must fire in a specific order and against each other’s force to generate a smooth and equally balanced movement. If one of those six muscles fires incorrectly, neither the upward nor downward rotation of the scapula will occur correctly. In such case, movement is impaired and may lead to the shoulder’s most common pathology: Impingement.

Now that we have reviewed the general aspects of SDRS, let us look at the most common clinical condition contributing to this syndrome: Rotator Cuff Tendinopathy and Impingement. The pinching of any soft tissue structure between the head of the humerus (from below) and the acromio-clavicular joint (from above) in clinical practice is referred to as Impingement of the Shoulder. Various soft tissue structures can be impinged between two bone structures (i.e., AC joint and head of the humerus): the subacromial bursa, the rotator cuff tendons, or the tendon of the long head of the biceps brachii muscle (Sahrmann, Shirley, 2002).

Which came first, the chicken or the egg? Does local inflammation in the form of tendinopathy supersede impingement or vice versa? Another critical question that the practitioner should answer is if the peripheral nerve, which innervates the shoulder joint, is irritated somewhere and therefore, could be the initial cause of the shoulder’s problem.

The therapist must understand that tendonitis and impingement go hand in hand, but are two distinct creatures. The tendon that is inflamed, (i.e., tendonitis or tendinopathy) is treated much differently than the impingement, which is a more global response to the insufficient upward rotation of the scapula causing the humerus to impinge against the coracoacromial ligament (Sahrmann and Shirley, 2002). Additionally, irritation of the brachial plexus by the anterior scalene muscle will mimic the clinical picture of tendinitis without local inflammation in the tendon being the initial trigger.

Very frequently, the doctor’s referral may state a diagnosis such as, “Shoulder Pain” or “Shoulder Tendonitis.” Despite that these diagnoses are correct to obtain reimbursement from medical insurance companies, they do not give the practitioner sufficient information on how to formulate a treatment protocol. The correct treatment must be based on a clinical evaluation of the soft tissue over the shoulder joint and its functions using valid testing methods. Thus, as a therapist, it will be our job to make correct clinical decisions to determine what the initial cause of the pain is: local inflammation, movement impairment syndrome or chronic irritation of the peripheral nerve responsible for the innervation of the shoulder joint. For example, if a patient was referred with a diagnosis of Shoulder Tendonitis, the therapist needs to know whether the long head of the biceps brachii tendon or the supraspinatus tendon are involved or both. In addition, the therapist needs to rule out any irritation of the brachial plexus for every client with shoulder pain.

Let us put the evaluation of the shoulder in the correct clinical order. There are four consequent steps in evaluation of the shoulder:

1. First the practitioner needs to observe the function of the affected joint.

Pay attention to the client’s body language as soon as you see him or her in your therapy room. Ask the client to show you the movement or restriction that causes the most discomfort. Visually observe the movement and compare it with unaffected side. 

2. Examine the potential irritation of the nerves innervating shoulder joint.

Use Wartenburg’s test for the anterior scalene muscle and Compression Test for the Pectoralis Minor muscle since tension in these muscles will elicit pressure on the brachial plexus in the anterior neck in the first case and in the anterior shoulder in the second case. In turn, mild irritation of the brachial plexus will mimic various pathological conditions in the area of the shoulder.

3. Examine the shoulder using the basic orthopedic tests we discuss below.

Also, the therapist may enhance the accuracy of the evaluation by performing Range of Motion (ROM) assessments using a goniometer. This may be beneficial in determining functional deficits and later used to detect progress of the therapy. It also gives additional validity to the paperwork submitted to the doctor’s office or insurance company. 

4. Finish the evaluation with a palpatory examination of each muscle.

Separately examine each muscle we discussed above to detect local spasm, hypertonus or trigger point locations. 

VISUAL OBSERVATION

The video below illustrates the visual observation of shoulder impairment on the example of weak and painful abduction in the left shoulder joint. The client was asked to slowly perform a bi-lateral abduction in both shoulder joints. As you see in the video, on the affected side, the activation of the pain analyzing system prevents an active abduction in the shoulder joint, which instead forces him to elevate his upper shoulder (white arrow).

EXAMINATION OF BRACHIAL PLEXUS

1. Wartenberg’s Test (WT)

WT gives 100% accurate information if tension developed in the anterior scalene muscle (ASM) that in turn compresses the brachial plexus against the middle scalene muscle.

The first part of the video shows the initial placement of the practitioner’s thumb for the execution of the test.

Notice that the thumb must be placed flat just above the clavicle. The second part of the video shows the application of the pressure in the correct spot. Notice how the thumb rotates and pushes down behind the clavicle. When applying pressure on the correct spot, the tendinous part of the ASM is felt as a cord, and the practitioner feels pulsation of the subclavian artery under the finger.

WT is considered positive if the patient feels acute pain while the practitioner applies even moderate pressure in this area or an already existing symptom gets worse, e.g., pain radiates to the shoulder, or paraesthesia (i.e., sensation of tingling) becomes numbness, etc.

2. Compression Test for Pectoralis Minor Muscle (CT)

CT gives 100% accurate information if the Pectoralis Minor Muscle irritates the brachial plexus. At the beginning, the video shows the client’s position during the application of the CT. Notice that the client’s palms are turned skyward (supination). The second part of the video shows the application of the CT to examine Pectoralis Minor Muscle.

The CT is considered positive if the patient reports acute pain under the practitioner’s thumb or pain or any other uncomfortable sensations appear in the area of the shoulder.

BASIC ORTHOPEDIC TESTSHere are basic orthopedic tests to examine function of the shoulder joint (Fig. 4). 

ORTHOPEDIC ASSESSMENT: SHOULDER IMPINGEMENT
Biceps Tendon (long head)	Yergason’s Test or Speed Test
Supraspinatus Tendon	Hawkins Kennedy Impingement Test
Both Biceps and Supraspinatus	Neer’s Sign

Fig. 4. Basic orthopedic tests to evaluate function of the shoulder joint (Donatelli,1997).

1. Yergason’s Test (YT)

YT allows us to detect the presence of tendonitis of the long head of biceps brachii muscle. The client is standing. The practitioner should bring the client’s arm in 90 degree flexion in the elbow joint with the client’s thumb facing the ceiling. Thus, the forearm is in a neutral position, which is half-pronation/half-supination.

Now, ask the client to actively supinate the forearm while the therapist resists this movement by counter force applied above the wrist joint while the therapist’s other hand stabilizes the elbow. YT is considered positive if the client feels pain in the anterior shoulder in the bicipital groove during active supination of the forearm.

2. Speed Test (ST)

ST also examines the presence of inflammation in the tendon of the long head of the biceps brachii muscle. The client is in the standing position with his forearm in complete supination (i.e., palm faced forward). Now, ask the client to slowly elevate the entire upper extremity without bending the elbow. While the client does this, the practitioner should provide counter resistance but with enough pressure that the client is only able to elevate the arm with significant difficulty. ST is considered positive if, during the active arm elevation against the examiner’s resistance, the client feels pain on the anterior shoulder in the area of bicipital groove.

YT is considered more sensitive than ST in regard to tendonitis of the long head of biceps (Holtby and Razmjou, 2004).

3. Hawkins’ Test (HT)

HT allows us to detect tendonitis of the supraspinatus muscle (see video below). The practitioner should passively abduct the arm approximately to 90 degrees in the shoulder joint (phase 1) and after this passively flex the elbow to 90 degrees as well (phase 2). From this position, use passive inner rotation in the shoulder joint (phase 3). Be sure that the patient does not participate in all these maneuvers. HT is considered positive if the patient feels acute pain during the inner rotation.

4. Neer Sign (NS)

NS allows us to determine if the tendon of supraspinatus or infraspinatus muscles or long head of biceps brachii muscle is pinched between the head of the humerus and the AC joint. The client is in the sitting position. The examiner is standing behind and to the side of the client. The examiner places one hand on the client’s shoulder and stabilizes it by pushing the shoulder down. The other hand grabs the client’s forearm and passively pronates it. Now, ask the client to tighten the elbow only. The examiner elevates entire upper extremity as high as it goes while pushing down on the shoulder with other hand without any active participation from the client (the therapist must feel the weight of the upper extremity).

NS considered positive if the client feels pain in the area of shoulder joint. However, there are important distinctions in the localization of the pain since three structures can be compressed between the head of the humerus and the AC joint (supraspinatus, infraspinatus and tendon of long head of the biceps). Thus, the examiner may get three possible readings:

a. The client feels pain anteriorly to the AC joint. It is more likely inflammation of the tendon of long head of the biceps brachii muscle 
b. The client feels pain on the top of the shoulder joint directly under the AC joint. It is more likely inflammation or tear of the supraspiantus muscle. 
c. The client feels pain slightly behind the AC joint. It is more likely inflammation or a tear in the infraspinatus muscle 

By understanding the complex nature of movement impairments of the scapulothoracic region, in this case SDRS, the therapist will be able to assess and address the original cause of the problem, restoring balance in the function of the shoulder joint and eliminate movement impairment syndrome.

REFERENCESDonatelli, Robert A. Physical Therapy of the Shoulder. 3rd Edition. Churchill Livingstone, Inc, Philadelphia, 1997
Frankel, VH, Nordin M. Basic Biomechanics of the Skeletal System. Lea & Febiger, Philadelphia, 1980
Holtby R., Razmjou H. of the Speed’s and Yergason’s tests in detecting biceps pathology and SLAP lesions: comparison with arthroscopic findings. Arthroscopy, Mar;20(3):231-6, 2004
Sahrmann, Shirley A. Diagnosis and Treatment of Movement Impairment Syndromes. Mosby, St. Louis, 2002

Category: Medical Massage

Tags: Journal of Massage Science 2013 #4