Suprascapular Nerve Block and Proprioception in Hemiplegic Shoulder Pain: A Randomized Controlled Study

Effects of Suprascapular Nerve Block on Proprioception in Hemiplegic Shoulder Pain: A Randomized Controlled Trial

The purpose of this prospective randomized controlled clinical trial is to evaluate the effect of suprascapular nerve block on shoulder joint proprioception in stroke patients with hemiplegic shoulder pain.

Fourteen patients aged 18-80 years with hemiplegic shoulder pain will be randomized into two groups. One group will receive suprascapular nerve block followed by a standardized physical therapy program, while the control group will receive the same physical therapy program alone.

The primary outcome is shoulder joint proprioception. Secondary outcomes include pain intensity, shoulder range of motion, motor recovery, stroke-specific quality of life, and upper extremity functional outcomes.

The results of this study are expected to clarify the role of suprascapular nerve block on proprioception and rehabilitation outcomes in patients with hemiplegic shoulder pain.

Hemiplegic shoulder pain is one of the most common painful complications following stroke, with a reported prevalence ranging from 16% to 84%. Its etiology is multifactorial and primarily includes musculoskeletal pathologies such as adhesive capsulitis, bicipital tendinitis, subacromial bursitis, shoulder subluxation, and rotator cuff disorders. Pain that may be present even at rest or during passive movement, along with reduced shoulder range of motion, represents the leading clinical complaint. Therefore, the main goal of treatment is to reduce pain, increase joint range of motion, and consequently enhance participation in rehabilitation and functional capacity.

Suprascapular nerve block is a widely used intervention to reduce pain and improve shoulder range of motion in patients with hemiplegic shoulder pain. Proprioceptive and nociceptive receptors embedded in the glenohumeral joint capsule and surrounding ligaments play a crucial role in joint stability, and the suprascapular nerve provides major innervation to these structures. Despite its widespread use to facilitate rehabilitation and improve outcomes, the effects of suprascapular nerve block on shoulder joint proprioception and the subsequent impact of potential proprioceptive changes on rehabilitation outcomes have not yet been investigated.

This study is designed as a prospective, controlled, investigator-blinded, parallel-group clinical trial. Fourteen stroke patients aged 18-80 years with hemiplegic shoulder pain will be enrolled and randomized into two groups. After baseline assessment (T0), one group will receive a suprascapular nerve block followed by a standardized physical therapy program, while the control group will receive the same physical therapy program alone. Follow-up assessments will be performed at 2 hours post-intervention (T1, intervention group only), at the end of the 3-week rehabilitation program (T2), and at week 7 (T3).

The primary objective of this study is to evaluate the effect of suprascapular nerve block on shoulder joint proprioception in stroke patients with hemiplegic shoulder pain. Secondary objectives include assessing its effects on pain intensity, shoulder range of motion, post-stroke motor recovery, stroke-specific quality of life, and upper extremity physical function and symptoms.

The null hypothesis is that suprascapular nerve block does not impair shoulder joint proprioception in patients with post-stroke hemiplegic shoulder pain.

Inclusion Criteria:

• Age between 18 and 80 years
• Presence of shoulder pain on the hemiplegic side with a Numeric Rating Scale (NRS) score > 3
• At least 1 month since the cerebrovascular event (subacute and chronic stroke patients)
• Active shoulder flexion range of motion > 90 degrees (required for the application of the laser pointer-assisted joint position sense test)
• First-ever, unilateral hemiplegia

Exclusion Criteria:

• Mini-Mental State Examination score < 24 indicating cognitive impairment
• Presence of aphasia
• Shoulder spasticity with a Modified Ashworth Scale score > 2
• Brunnstrom upper extremity motor stage < 3
• Botulinum toxin type A injection within the last 3 months to muscles affecting shoulder joint movement (trapezius, levator scapulae, pectoralis major, deltoid, serratus anterior, latissimus dorsi, rhomboids, teres major, biceps, coracobrachialis, triceps, supraspinatus, subscapularis, infraspinatus, and teres minor)
• Pre-existing shoulder pathology causing pain in the hemiplegic shoulder
• Presence of neglect syndrome
• Complex regional pain syndrome, central pain, traumatic brachial plexus injury
• Change in pain medication during the study period
• Hypersensitivity to the medication used for suprascapular nerve block (lidocaine)
• Adhesive capsulitis (frozen shoulder)
• Other shoulder pathologies such as fractures or joint replacement