The guidelines established by the New York State Workers Compensation Board are crafted to assist healthcare professionals in providing appropriate treatment for impingement syndrome.
Tailored for medical practitioners, these Workers Compensation Board guidelines offer support in determining the suitable approach for individuals with impingement syndrome.
It’s crucial to note that these guidelines do not replace clinical judgment or professional experience. The final decision on treatment for impingement syndrome should be a collaborative one, involving the patient and their healthcare provider in consultation.
Shoulder Impingement Syndrome Overview
A compilation of symptoms rather than a pathological diagnosis, shoulder impingement syndrome arises from the encroachment of the acromion, coracoacromial ligament, coracoid process, and/or the AC joint on the rotator cuff mechanism during shoulder movement.
The rotator cuff mechanism, passing beneath these structures, is closely related to the coracoacromial arch, separated only by the thin bursa surfaces.
Compression and friction can be minimized by factors such as the shape of the coracoacromial arch, the normal undersurface of the AC joint, a normal bursa, normal capsular laxity, and coordinated scapulothoracic function.
This syndrome may be associated with AC joint arthritis, partial- and full-thickness rotator cuff tears, and adhesive capsulitis/frozen shoulder. The normal function of the rotator cuff mechanism and the biceps tendon helps alleviate impingement syndrome.
History and Mechanism of Injury
Mechanism of Injury: Established repetitive overuse of the upper extremity, often observed with frequent overhead motion.
History May Include:
- Delayed Presentation: As the syndrome is typically not an acute problem, patients seek care if their symptoms persist despite rest, time, and attempts to resolve.
- Complaints of Functional Losses: Due to pain, stiffness, weakness, and catching when the arm is flexed and internally rotated.
- Common Symptoms: Poor sleep is common, and pain is often felt down the lateral aspect of the upper arm near the deltoid insertion or over the anterior proximal humerus
Physical Findings
- Inspection of the shoulder: May reveal deltoid and rotator cuff atrophy.
- Range of motion: Limited, particularly in internal rotation and cross-body adduction.
- Passive motion: Through the 60 to 90-degree arc of flexion may be accompanied by pain and crepitus, accentuated during shoulder movement in and out of internal rotation.
- Active elevation: Usually more uncomfortable than passive elevation.
- Pain on maximum active forward flexion: Frequently observed with impingement syndrome but is not specific for diagnosis.
- Strength testing: May reveal weakness, attributed to pain, disuse, tendon damage, or poor scapulothoracic mechanics.
- Pain on resisted abduction or external rotation: May indicate compromised integrity of the rotator cuff tendons.
- Weakness of posterior scapular stabilizers: Seen as a contributing factor to impingement syndrome by altering the mechanics of the glenohumeral joint.
Laboratory Tests
- Generally not indicated
- Recommended in select patients where a systemic illness or disease is suspected.
Testing Procedures: X-Ray
- Recommended in select patients as clinically indicated.
- Indications: May demonstrate calcification or bone spurs.
Subacromial Space Injection
- Recommended in select patients as clinically indicated.
- Indications: Can be used as a diagnostic procedure by injecting an anesthetic (e.g., sensorcaine or xylocaine solutions) into the space. If pain is alleviated with the injection, the diagnosis is confirmed.
Adjunctive Testing (Sonography, Arthrography, or MRI)
- Recommended in select patients as clinically indicated.
- Indications: Techniques such as sonography, arthrography, or MRI should be considered when shoulder pain persists despite 4-6 weeks of non-operative conservative treatment, and the diagnosis is not readily identified through history and clinical examination.
Non-Operative Treatment Procedures
- Medications: Such as nonsteroidal anti-inflammatories and analgesics.
- Subacromial Space Injection:
- Recommended in select patients as clinically indicated.
- Indications: Therapeutic if the patient responded positively to a diagnostic injection of an anesthetic. Steroid injections directly into the tendons are not recommended.
- Frequency: Not exceeding two to three times annually. Usually, one or two injections are adequate.
- A minimum interval of three weeks between injections is recommended.
- Time to produce effect: Immediate with local anesthetic or within three days with corticosteroids.
- Maximum duration: Limited to three injections annually at the same site.
- Relative rest, immobilization, thermal treatment, ultrasound, therapeutic exercise, and physical medicine and rehabilitation should be considered.
- Recommended
Post-Operative Procedures
Individualized rehabilitation programs based upon communication among the physician, the surgeon, and the therapist might include:
- Sling or abduction splint;
- Gentle pendulum exercise, passive glenohumeral range of motion, and aggressive posterior scapular stabilizing training can be instituted;
- At four weeks post-operative, begin isometrics and ADL involvement; and/or
- Depending upon the patient’s functional response, at six weeks post-operative consider beginning light resistive exercise; concomitantly, return to light/modified duty may be plausible given the ability to accommodate “no repetitive overhead activities.”
Progressive resistive exercise from two months with gradual returning to full activity at 5-7 months; all active non-operative procedures listed in Section E, Therapeutic Procedures: Non-Operative, should be considered.
Work restrictions should be evaluated every four to six weeks during post-operative recovery and rehabilitation with appropriate written communications to both the patient and the employer. Should progress plateau, the provider should reevaluate the patient’s condition and make appropriate adjustments to the treatment plan.
