Causes of Shoulder Pain in Hemiplegic Patients: A Comprehensive Guide

Shoulder pain is one of the most prevalent and debilitating complications experienced by individuals recovering from hemiplegia, particularly after a stroke. This discomfort not only affects daily functioning but can also hinder rehabilitation progress. Understanding the underlying causes is crucial for effective management and improved quality of life.

1. Muscle Spasticity Around the Shoulder Joint

Following a stroke or brain injury, many patients develop increased muscle tone, commonly known as spasticity. In the upper limb, this often leads to abnormal posturing—typically characterized by flexion of the elbow, wrist, and fingers, along with internal rotation of the shoulder. This persistent muscle tightness around the shoulder joint restricts normal movement and creates mechanical stress, resulting in sharp or aching pain during passive or active motion. The spastic muscles pull unevenly on the joint, contributing to both discomfort and reduced range of motion.

Impact on Daily Activities and Rehabilitation

Spasticity-related shoulder pain can severely limit a patient's ability to perform basic self-care tasks such as dressing, grooming, or reaching for objects. Moreover, it may interfere with physical therapy sessions, making exercises painful and less effective. Early intervention with stretching routines, neuromuscular electrical stimulation, and medications like botulinum toxin injections can help reduce spasticity and alleviate associated pain.

2. Soft Tissue Pathologies and Adhesive Capsulitis

Due to limited mobility on the affected side, hemiplegic patients often experience decreased use of their paralyzed arm. This lack of movement can lead to stiffness and inflammation within the shoulder joint capsule—a condition known as adhesive capsulitis, or "frozen shoulder." Adhesions form between the connective tissues surrounding the joint, significantly restricting mobility and causing chronic pain.

Progression and Long-Term Consequences

If left untreated, adhesive capsulitis can progress through freezing, frozen, and thawing stages, each lasting several weeks to months. During the early phases, pain is typically worse at night or with attempted movement. Over time, even minor movements become excruciating. Physical therapy focused on gentle mobilization, combined with heat therapy and anti-inflammatory treatments, plays a key role in preventing or reversing this condition.

3. Shoulder Subluxation Due to Muscle Weakness

In the flaccid stage following a stroke, when muscle tone is drastically reduced, the shoulder girdle loses its primary stabilizers—particularly the rotator cuff muscles and deltoid. This muscular weakness allows the humeral head to slip downward and forward out of the glenoid cavity, leading to partial dislocation, or subluxation. This misalignment stretches the joint capsule and surrounding ligaments, potentially compressing nerves such as the brachial plexus, which results in pain, numbness, or tingling.

Risk Factors and Preventive Strategies

Subluxation is more common in patients with severe initial paralysis and poor trunk control. While supportive slings were once widely used, modern rehabilitation emphasizes proper positioning, neuromuscular re-education, and functional electrical stimulation to strengthen weakened muscles. Evidence suggests that early mobilization under professional guidance helps maintain joint integrity and reduces long-term complications.

In conclusion, shoulder pain in hemiplegic individuals stems from a combination of neurological, biomechanical, and inflammatory factors. Addressing these issues requires a multidisciplinary approach involving neurologists, physiatrists, physical therapists, and occupational therapists. By identifying the root cause early and implementing targeted interventions, patients can achieve better pain control, enhanced mobility, and greater independence in everyday activities.