Increase referrals and revenue by incorporating diagnosis and conservative management of subacromial impingement syndrome

The shoulder girdle is an engineering marvel. It is the only joint complex in the human body that can move forward, backward, up, down, out to the sides, and rotate a full 360°. However, it is this extreme mobility that leads to the majority of shoulder injuries. Many of these injuries are sports related, with the highest percentage in tennis, swimming, baseball pitching, and weightlifting. One of the more common shoulder pathologies is subacromial impingement syndrome.

Can’t Shrug Off the Pain
Everyday activities involving arm use at or above shoulder level will cause some degree of impingement in all of us. However, sudden movements, continually working with arms raised overhead, or other repetitive actions of the shoulder can cause this impingement to become painful. With athletes, impingement syndrome will commonly result from overuse or improper techniques. They can develop ligamentous and capsular laxity in the shoulder joint from repetitive overhead activities—serving a tennis ball, pitching a baseball, spiking a volleyball—that will cause the shoulder joint structures to shift, thereby placing more stress on the rotator cuff. These cuff muscles—with the sole purpose of stabilizing the shoulder—become fatigued, which allows the humeral head to rise into the acromion and impinge on subacromial structures, such as the supraspinatus tendon, subacromial bursa, and long head of the biceps.

Patients usually present with complaints of shoulder pain, loss of range of motion (ROM), and possibly weakness of the shoulder musculature. The onset can either be acute following an injury, or insidious, particularly in the older population. Patients may state that any above-the-shoulder makes the pain worse. Throbbing night pain, especially when laying on the involved shoulder is a common complaint. Additional symptoms may consist of pain when reaching into the back pocket, or trying to reach across body to scratch the other shoulder.

Diagnosis of impingement syndrome can be made with a thorough clinical history and examination. However, be sure to rule out other common causes of shoulder pain, which include, but are not limited to, rotator cuff tear, shoulder dislocation, glenohumeral arthritis, biceps tendon rupture, calcific tendonitis, cervical radiculopathy, thoracic outlet syndrome, adhesive capsulitis, and acromioclavicular joint separation. Once a working diagnosis has been made, use an integrated approach to address all of the possible contributors to impingement.

The clinical presentation of impingement syndrome is commonly divided into three stages.¹ As chiropractors, we will be most effective with stages I and II pathologies.

Stage I: Usually reversible with conservative care. Involves swelling, often occurs in patients less than 25 years of age, and is frequently associated with overuse injuries (ie, spiking a volleyball, throwing a baseball).

Stage II: More advanced and tends to occur in patients 25 to 40 years of age. Pathologic changes such as fibrosis and tendon changes can now be seen on magnetic resonance imaging (MRI) or x-ray. Untreated impingement syndrome will frequently lead to Stage III pathology.

Stage III: Generally occurs in patients over 50 years of age and frequently involves a tendon rupture or tear.

Fine-tooth Comb Exam
When examining your patients, have them suitably dressed to expose the thoracic spine and shoulder girdle. Ask female patients to bring a tank top or bathing suit top, if possible.

Many practitioners miss important subtleties by not taking a moment to stop and look. Evaluate the contour of the whole shoulder girdle (bony and soft tissue) and compare it to the healthy shoulder. Look to see whether the scapulae are symmetrical and whether there is any winging. Check for swelling or depressions (step-off) around the acromioclavicular or sternoclavicular joints. Evaluate any thoracic kyphosis. Patients with chronic shoulder pain will often demonstrate compensatory changes in shoulder musculature and posture.

Palpate the shoulder for crepitus and tenderness in different anatomical positions to help clearly define pain patterns. Remember to palpate for tenderness at the following key areas: posterior aspect of the shoulder, levator scapula, supraspinatus, teres minor, cervical and thoracic spine, medial border of the scapula, acromioclavicular joints, coracoid process, bicipital groove, and sternoclavicular joints.

Figure 1. Posterior glide check in supine position.

Check for glenohumeral joint capsule laxity or tightness by having patients prone and supine with involved shoulder slightly off edge of table (Figure 1). The examiner should check anterior and posterior glide, as well as internal and external rotation. In a shoulder with laxity, you will feel less tension at the end-range of joint movement. Joint laxity is commonly encountered in athletes who throw, especially external rotation in the throwing arm. Be sure to compare bilaterally.

It is important to perform your ROM testing actively, passively, and with resistance. Shoulder dysfunction can remain hidden if only one type of ROM is evaluated. Many times, patients will have personal reasons for not wanting to express the severity of pain to you (ie, athletes who do not want to be taken out of play or employees afraid of being fired). Look for apprehension or guarding in these patients during movement.

Scapular muscle dysfunction is a common finding in subacromial impingement syndrome, although research has yet to determine whether this represents a primary or secondary (compensatory) dysfunction. However, it is crucial to improve scapular function during the treatment phase for best results.

Further Testing Required
Once you have established a baseline for any muscle dysfunction, orthopedic testing will reveal any other pathology. Virtually all orthopedic subacromial impingement tests involve some element of moving the shoulder passively into internal rotation, which is painful because it rotates the vulnerable supraspinatus tendon underneath the acromion and coracoacromial ligament. This is where there is the least space and where the supraspinatus tendon gets squeezed the most.

Figure 2. Neer’s orthopedic test.

The two most common tests used for shoulder impingement syndrome are Neer’s and Hawkin’s. Neer’s test (Figure 2) involves raising the arm overhead, pointing straight up with elbow locked.²,³ Internally rotate the arm so that the palm is facing outward. Gently force elbow towards the head. Pain in the shoulder would be considered a positive test. Hawkin’s test (Figure 3) is performed by first having the examiner passively abduct and internally rotate the painful shoulder.⁴,⁵ Let fingertips point straight down. Keeping the arm in internal rotation, slowly carry elbow across front of the body.

Figure 3. Hawkin’s orthopedic test.

Other tests that can be helpful to rule in or rule out your diagnosis include Yeargeson’s, Drop Arm, and Apprehension tests. Additional testing of the shoulder should include biceps/triceps reflexes and sensory testing as pain can be referred from the neck.

Plain x-rays can also play an important role in the diagnosis of shoulder abnormalities and help determine if there are any major joint or tendon changes. Routine views (anterior-posterior with internal and external rotation and axillary lateral) provide an excellent overview of the region. Supraspinatus outlet views with caudal rotation can also be obtained to further evaluate subacromial impingement.

Red-Carpet Treatment
For purposes of this article, I will assume a working diagnosis of phase I subacromial impingement syndrome has been made.

As chiropractors, we sometimes have the tendency to practice with blinders on. In this situation, we must think outside of the box and utilize several different techniques to effectively treat this condition. Manipulation, Active Release™, nutritional supplements, and strengthening/ stretching programs can all be used. Methods of treatment will depend on several factors such as clinic set-up, patient age, compliance and motivation, and past medical history.

In many situations, patient compliance will be your most difficult undertaking. Do not let patients tell you they “work through pain to loosen up and then it feels better.” This only leads to further irritation to the involved structures and eventual chronicity. For athletes, it is extremely important to provide an alternate form of exercise—there is nothing worse you can do than tell them to stop exercising. This will only decondition them and at times, induce short-term depression. Be sure to involve patients in all phases of care to keep them focused and compliant.

Figure 4. Internal stretch using towel behind back.

In the acute stage, the primary goal of treatment is to decrease inflammation, avoid aggravating activities, and to rest the injured shoulder. Gentle mobility exercises can be used early in the treatment program depending on pain level.

Natural anti-inflammatories or NSAIDs can be used when indicated. Ice wrapped around the shoulder for 20 to 25 minutes is effective in decreasing inflammation found with impingement. Always use ice after your treatment program, as using ice before treatment will only make stretching of tissues more resistant to movement.

Figure 5. Laying supine with bad shoulder/hand behind back to stretch internal rotators.

Internal rotation stretching can be performed by having patients reach behind the neck with the asymptomatic arm, while simultaneously reaching behind the back with the painful shoulder (Figure 4). A towel or rope is used to connect the two hands. The good hand will pull towards the ceiling, gently moving the bad shoulder into maximum internal rotation. Another option is to have patients lay supine and bring the hand of the injured shoulder underneath the lower back. Have patients incrementally bring their hand up the spine, resting with each movement to allow the involved tissues to stretch (Figure 5).

The Chiropractic Advantage
Posterior and inferior glenohumeral joint restrictions, which cause excessive anterior and superior glide of the glenohumeral joint leading to impingement, are common. This is where chiropractic manipulation has an advantage over other specialties. It is important to manipulate and stretch capsular joint restrictions during this treatment phase.

Figure 6. Posterior joint stretch using pillow.

An easy posterior capsule stretch is to have patients place a large pillow at the axilla region and horizontally adduct their injured shoulder across the pillow with the arm straight and thumb pointing upwards. Place the opposite hand on the triceps (make sure their hand is above the elbow). Gently press the injured arm toward their body, stopping when slight tension is felt (Figure 6).

Improving scapular movement is an integral part of any well-planned shoulder rehabilitation program.⁶ Have patients laying on their unaffected side. Stand behind the patient, and while keeping the body “squared,” move the scapula of the affected side in all planes of movement (Figure 7). This is to be done first passively by the examiner and then with increasing resistance. Be sure to address all possible movements of the scapula.

Figure 7. Side-lying scapular glide.

Within several weeks, patients should be relatively pain-free during most movements and ready to begin strengthening the scapula stabilizers and rotator cuff muscles. If this stage is skipped and return to play or normal activities allowed, symptoms are likely to return.

The easiest and least expensive rehabilitation tool is stretchable rubber tubing for both office and home use. Purchasing the tubing in 30-ft rolls and cutting them down to 6-ft pieces is the most economical approach. These 6-ft pieces can be knotted easily and made similar to its more expensive counterparts.

Many sports—baseball, racquetball, volleyball, golf—require a treatment program designed to facilitate shoulder endurance by using movements high in velocity and relatively low in amplitude. While sports such as weightlifting, football, bodybuilding, and archery require a rehabilitation program geared more toward low velocity and high amplitude training. Design your treatment program around patient needs by asking them what is required for work or play.

Figure 8. Tubing internal and external rotation.

Slow and Easy
It is important to have patients initially perform slow movements, higher repetitions with a lighter weight. As endurance and lack of symptoms permit, increase the speed of movements and keep the weight or resistance relatively unchanged. For internal and external strengthening, have patients stand with arms at their side and elbow flexed to 90° (Figure 8). Begin with three sets of 25 to 100 repetitions each, and perform multiple daily sets. Perform movement slowly and evaluate pain. If no symptoms are elicited, increase speed of repetitions. Be sure to perform resisted internal, external, abduction, adduction, flexion, and extension movements using the tubing in both neutral and throwing positions. For home exercises, have patients use the tubing exercises two to three times daily followed by cryotherapy.

Figure 9. Prone scapula protraction.

Many exercise programs focus on strengthening scapular elevation and retraction, but few focus on scapular depression and protraction. An effective exercise to strengthen scapula protraction is to have patients lay prone on their elbows (Figure 9). Allow the chest to dip towards the floor and then raise the chest allowing both scapulae to protract. To strengthen scapular depression, have patients support themselves on their forearms between two treatment tables or chairs (Figure 10). Slowly elevate the body by using only shoulder and scapula motion. Make sure to have patients do shoulder shrugs, bent-over flys, push-ups, and pull-ups.

Figure 10. Seated scapula depression between two chairs or tables.

Treatment of this injury will take more time than a typical spinal misalignment. By following these simple protocols, you now have a starting point and will be able to efficiently handle many cases that, in the past, you would have referred out, had a poor success rate, or would never have been referred to you initially. CP

Craig D. Cook, DC, CCSP, QME, runs two multidisciplinary clinics, Procare Sports Chiropractic, San Diego, and is the team chiropractor for the San Diego Padres. He also lectures at Kaiser Permanente Hospital, San Diego, regarding chiropractic issues and founded Cook Forms, a software company that provides chiropractic forms. Cook can be reached via email: spinedoc@pacbell.net

References
1. RJ Hawkins and JS Abrams. Impingement syndrome in the absence of rotator cuff tear stages 1 and 2. Orthop Clin North Am. 1987;18:373.
2. Calis M, Akgun K, Birtane M, Karacan I. Diagnostic values of clinical diagnostic tests in subacromial impingement syndrome. Ann Rheum Dis. 2000;59:44–47.
3. Neer CS II. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Joint Surg. 1972;54(1): 41–50.
4. Hawkins RJ, Hobeika PE. Impingement syndrome in the athletic shoulder. Clinics in Sports Medicine. 1983;2(2):391–405.
5. Hawkins RJ, Kennedy JC. Impingement syndrome in athletes. Am J Sports Med. 1980;8(3):151–8.
6. Souza TA. Sports Injuries of the Shoulder: Conservative Management. New York: Churchill Livingstone; 1994:26–265.