Stroke is a leading cause of adult disability worldwide. Among its most functionally limiting complications is upper extremity spasticity - a velocity-dependent increase in muscle tone that restricts arm and hand function, impairs daily activities, and reduces quality of life. Current treatment options such as oral antispastic agents and botulinum toxin injections are associated with systemic side effects, high cost, invasiveness, or short duration of effect.

Radial extracorporeal shock wave therapy (rESWT) is a non-invasive modality that delivers acoustic pressure waves to target tissues and has shown promising antispastic effects through both neural and biomechanical mechanisms.

This prospective observational study (N=21) evaluates the effects of upper extremity rESWT on spasticity, pain, motor function, functional independence, and quality of life in individuals with post-stroke hemiplegia. rESWT was applied to three muscle groups (biceps brachii, flexor carpi radialis, and flexor carpi ulnaris) at 2,000 impulses per muscle, 5 Hz, 1.5 bar, twice weekly for 4 weeks (8 sessions total). Outcomes were assessed at three time points: baseline, month 1, and month 3.

Stroke ranks first among causes of adult disability and second among causes of mortality worldwide. Post-stroke spasticity develops in 4% to 50% of patients within the first six months after stroke, depending on lesion localization and timing of assessment. In the upper extremity, spasticity typically manifests as shoulder adduction and internal rotation, elbow flexion, forearm pronation, and wrist/finger flexion severely limiting functional use of the hand and arm. Associated pain, spasms, and joint contractures further reduce quality of life and rehabilitation motivation.

Conventional antispastic treatments carry notable limitations: oral agents produce sedation and generalized muscle weakness; botulinum toxin injections are costly, invasive, limited in duration, and carry a risk of neutralizing antibody development with repeated use. These limitations have prompted growing interest in rESWT as a non-invasive, low-side-effect alternative with multifactorial antispastic mechanisms, including modulation of motor neuron excitability, improvement of passive muscle elasticity through fibrolytic effects, and facilitation of autogenic inhibition via Golgi tendon organ stimulation.

Study Design: Single-arm prospective observational study. Approved by the Ethics Committee of Sancaktepe Şehit Prof. Dr. İlhan Varank Training and Research Hospital (Decision No: 2025/214; Date: 11.06.2025). All procedures were conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participants.

Participants (N=21): Adults (≥18 years) with post-stroke hemiplegia of at least 4 weeks duration, Modified Ashworth Scale (MAS) score ≥2 in at least one upper extremity joint movement, and sufficient cognitive ability to follow simple commands.

Exclusion criteria included consciousness impairment, systemic contraindications to ESWT, shoulder subluxation on the affected side, skin integrity disruption at the application site, and botulinum toxin injection within the preceding 3 months.

Intervention: rESWT was applied to three muscle groups of the affected upper extremity - biceps brachii, flexor carpi radialis (FCR), and flexor carpi ulnaris (FCU) - using the following parameters: 2,000 impulses per muscle group, 5 Hz frequency, 1.5 bar pressure. Treatment was administered twice weekly for 4 weeks (8 sessions total). Anatomical target points were standardized according to the EUROMUSCULUS/USPRM guideline.

Outcome Measures: All assessments were performed at three time points: baseline (before rESWT initiation), month 1. and month 3.

Spasticity: Modified Ashworth Scale (MAS) Upper extremity motor function: Fugl-Meyer Upper Extremity Scale Functional independence: Modified Barthel Index Pain: Visual Analog Scale (VAS) Stroke-specific quality of life: Stroke Specific Quality of Life Scale (SSQLS) Proprioception: Clinical joint position sense assessment (categorized as intact, impaired, or not assessable)

Inclusion Criteria:

• Age 18 years or older
• Diagnosis of hemiplegia following stroke
• Minimum of 4 weeks elapsed since stroke onset
• Modified Ashworth Scale (MAS) score ≥ 2 in at least one upper extremity joint movement
• Sufficient cognitive ability to follow simple commands
• No botulinum toxin injection in the preceding 3 months
• Willing to participate and signed informed consent form

Exclusion Criteria:

• Impaired consciousness or severe cognitive deficit
• Systemic conditions contraindicating ESWT (active infection, malignancy, etc.)
• Shoulder subluxation on the affected side
• Skin integrity disruption at the application site