Effective Interventions for Post-Stroke Shoulder Subluxation and Pain

Stroke is a major cause of disability in the world; between 30% and 70% of people who survive a stroke experience a significant impairment of the affected arm and become functionally dependent on others for everyday activities.^1,2 The shoulder is highly vulnerable to secondary musculoskeletal complications following stroke,³ with the most recognized of these being shoulder subluxation.⁴

The glenohumeral joint is the main joint of the shoulder, and the shoulder complex consists of four separate joints which afford incredible mobility in all planes of motion, but at the expense of stability.⁴ The glenohumeral joint relies on muscle integrity and capsule-ligamentous structures rather than bony conformation for its stability. Injury or paralysis of the muscles around the shoulder complex may lead to glenohumeral joint subluxation and/or pain.⁵

Purpose

Hemiplegic shoulder pain and subluxation are common complications after stroke. Such pain may result in significant disability that may limit a patient’s ability to reach maximum functional potential and impede rehabilitation. Moreover, it may be an important contributor to the length of hospital stay and has been associated with depression and decreased quality of life.⁶

Although pain and subluxation often occur together, one does not necessarily cause the other, leaving clinical questions around the most effective intervention for treating both shoulder subluxation and pain together for stroke patients with a hemiplegic upper extremity. A review of existing literature provides guidance, particularly for occupational therapists who often specialize in facilitating upper extremity functions used in activities of daily living. Patients are often seen by occupational therapists in acute, post-acute, home health, and outpatient settings for complications related to cerebrovascular accidents affecting their participation in desired activities. While research in the field regarding these injuries has spanned decades, few measures have proven effective and efficient until more recently for selecting intervention methods and achieving stronger overall outcomes in patients.

Over 30 years, an overwhelming number of articles were found on both subluxation and pain treated together and separately in stroke patients, with the majority consisting of RCTs but evidence on effectiveness of treatments was mixed. (Image: iStock)

Current Data and Research

Using CINAHL, PubMed and the Academic Search Complete databases, the reviewers searched the following terms: stroke, CVA, cerebrovascular accident, ischemic stroke, shoulder subluxation, hemorrhagic stroke, intervention, strategies, best practices, hemiplegia, treatment, stroke patients, Kinesio taping, strapping, hemiplegic upper extremity, and therapy. A total of 54 unique articles were acquired and analyzed for relevance to post stroke patients with hemiplegic shoulder pain and/or subluxation. Only articles published in the last 10 years were included in order to gather the most current research; of this criterion, 17 articles remained.

Over the course of 30 years, an overwhelming number of articles were found on both subluxation and pain treated together and separately in stroke patients, with the majority consisting of randomized controlled trials (RCTs). Evidence on effectiveness of treatments within these articles was mixed due to the great number of treatment options and wide population variables studied. The more common treatment methods studied included:

• electrical stimulation (ES), including neuromuscular electrical stimulation (NMES) and functional electrical stimulation (FES)^7-14
• stretching^9,10
• taping^11,15,16
• slings/orthoses.^11,17,18,19

Commonly used outcome measures were:

• visual analogue scales (VAS) to measure pain^{13,14,17,20,21}
• Fugl-Meyer Assessment (FMA) to measure upper limb motor function^{9,17,20,21,22}
• Functional Independence Measure (FIM) to evaluate a patient’s functional status^15,20
• goniometers to measure both active and passive range of motion^7,16,17
• x-rays to measure degrees of subluxation^{7,13,14,19,21}
• the Modified Ashworth scale (MAS) to measure spasticity.^7,14,17,22

Of the articles analyzed, ES of the posterior deltoid, supraspinatus, and long head of biceps demonstrated the most effective treatment for both hemiplegic shoulder subluxation and pain.^7,8,11,12,13 While different treatments were useful in reducing one of the elements (subluxation or pain^{15,17,19,20,21,22}), only ES was consistently effective at reducing both. Use of ES often depended on a given clinician’s certifications, experience, and commonly used protocols.

Research on cutting-edge technology also showed interventions such as brain-controlled interface functional ES¹⁴ and robotic protocol²² improved shoulder subluxation in the short term but did not investigate the effects on pain for long-term, post-treatment subluxation results. Percutaneously implanted NMES improved hemiplegic shoulder pain but did not investigate effects on shoulder subluxation.¹¹ Task-oriented electromyography-triggered stimulation showed improvements in shoulder subluxation, pain, and other variables, but has yet to be validated by replicated studies.²¹ Only one study looked at long-term effects of any method showing that percutaneously implanted NMES alleviated pain for at least up to one year with regularly ongoing treatment and minimal adverse reactions.¹¹

It is also worth noting that prevention of post-stroke shoulder subluxation was shown to improve performance of task-specific, functional activities to increase voluntary motor control around the shoulder, but this treatment was not evaluated for pain prevention.¹²

Limitations

This review was limited to stroke-patient populations. Subjects ranged from acute post-stroke to long-term chronic stroke patients, creating a wide variance between time of stroke, duration of symptoms, and timing of treatment. In addition, most studies available had small, specific sample sizes making it more difficult to generalize results.

Discussion

Despite this lack of generalization, practitioners may consider implementation of electrical stimulation of the posterior deltoid, supraspinatus, and long head of biceps as the current best practice to reduce both pain and subluxation in the post-stroke hemiplegic shoulder. The supraspinatus and posterior deltoid combine to hold the glenohumeral joint in place, prevent sloping of the glenoid fossa, and hold correct alignment of the glenohumeral joint when activated in a healthy shoulder or through ES of the subluxed shoulder. The long head of the biceps plays a supporting role as it is located anteriorly and provides the glenohumeral joint both inferior and superior stability when activated. When activated, the combination of these muscles are thought to work in conjunction to prevent downward and anterior instability of the glenohumeral joint and therefore reduce subluxation.^7,12,13 The application of ES to these same muscles has also been shown to alleviate pain^7,8,11,13 though not always consistently.¹²

Replication of promising interventions, with various post-stroke populations is recommended to strengthen evidence and to discover other effective protocols for hemiplegic shoulder pain and subluxation.^14,21,22 •