Focal Vibration Therapy in Post-stroke Shoulder Pain

Official title

Efficacy of Focal Vibrational Therapy in Reducing Post-stroke Shoulder Pain: a Double-blind, Randomized Controlled Trial

Overview

Hemiplegic Shoulder Pain (HSP) is a common and disabling complication after stroke, negatively affecting upper limb function, participation in rehabilitation, and quality of life. Despite the widespread use of conservative and physical therapies, evidence supporting the efficacy of specific non-invasive neuromodulation techniques remains limited. Focal Vibration Therapy (FVT) is a non-invasive physical modality that delivers localized mechanical vibration to targeted muscles or tendons and may modulate pain, muscle tone, and proprioception through frequency-dependent mechanisms. This randomized controlled trial aims to evaluate the efficacy of a multimodal FVT protocol, in addition to standard rehabilitation, compared with a sham intervention plus standard rehabilitation, in reducing pain in patients with chronic post-stroke Hemiplegic Shoulder Pain.

Detailed description

Hemiplegic Shoulder Pain (HSP) is a frequent and disabling sequela of stroke, with reported incidence rates ranging from 30% to 65% within the first six months after stroke onset. This variability reflects differences in diagnostic definitions and heterogeneity among studied populations. The underlying pathophysiology of HSP is multifactorial, involving musculoskeletal alterations (e.g., glenohumeral subluxation), abnormal nociceptive processing and central sensitization, and spasticity-related impairments, particularly affecting shoulder adductor and internal rotator muscles.

HSP significantly interferes with post-stroke recovery by reducing upper limb motor performance and functional use, impairing participation in rehabilitation programs, and worsening quality of life. Although early and multidisciplinary management is recommended, available therapeutic approaches remain heterogeneous and include positioning strategies, manual therapy, pharmacological treatments, nerve blocks, botulinum toxin injections, dry needling, robotic-assisted therapy, and neuromodulation techniques.

Physical therapeutic modalities are commonly used in rehabilitation settings due to their non-invasive nature and potential analgesic and functional benefits. However, evidence regarding their specific effectiveness in the treatment of HSP is inconsistent, and existing reviews often include heterogeneous interventions or focus on invasive approaches, leaving uncertainty about the role of targeted physical neuromodulation.

Focal Vibration Therapy (FVT) is an emerging physical modality that applies localized mechano-sonic stimulation to muscle bellies or tendon insertions. Its effects are frequency-dependent and include modulation of nociceptive input through spinal gate control mechanisms at low-to-medium frequencies (approximately 35-50 Hz), modulation of muscle tone and proprioception through stimulation of Ia afferent fibers and induction of the tonic vibration reflex at intermediate frequencies (around 100 Hz), and modulation of deep pain perception through activation of Pacinian corpuscles at higher frequencies (approximately 200 Hz).

Given the multifactorial nature of HSP and the limitations of current conservative treatments, there is a need to investigate structured intervention protocols integrating advanced physical modalities with standard rehabilitation. This randomized controlled trial will compare a multimodal FVT protocol, delivered in addition to standard rehabilitation, with a sham intervention plus standard rehabilitation in patients with chronic post-stroke HSP. The study will assess changes in pain intensity as the primary outcome, along with secondary outcomes related to shoulder function, range of motion, spasticity, quality of life, persistence of treatment effects, and safety of the intervention.

Interventions

• Device Multimodal Focal Vibration Therapy (FVT)
  Participants in the experimental group will receive multimodal Focal Vibration Therapy (FVT) delivered using a medical vibration device, in addition to standard post-stroke shoulder rehabilitation. FVT will be applied to selected peri-scapular and shoulder muscles involved in pain generation and motor impairment, according to a standardized protocol. Each treatment session consists of two integrated phases. Physiokinesitherapy Phase (30 minutes): Participants will undergo a standardized rehabi
• Other Standard Rehabilitation Program
  All participants will undergo a standardized post-stroke shoulder rehabilitation program, including passive, active-assisted, and active exercises aimed at pain reduction, range of motion recovery, and functional improvement of the affected upper limb. Each session will consist of the same two phases as the experimental group. Physiokinesitherapy Phase (30 minutes): Identical to that administered in the experimental group. Sham Procedure Phase (25 minutes): Four transducers will be positione

Primary outcome measures

• Change in Pain Intensity Assessed by Numerical Rating Scale (NRS) [Time frame: From baseline (Day 0) to the Day 15 (end of treatment)]

Secondary outcome measures (6)

• Change in Shoulder Function and Disability (SPADI) [Time frame: Baseline (Day 0), Day 15 (end of treatment), and at 1, 3, and 6 months follow-up]
• Change in Glenohumeral Range of Motion (ROM) (degrees) [Time frame: Baseline (Day 0), Day 15 (end of treatment), and at 1, 3, and 6 months follow-up]
• Change in Upper Limb Spasticity (Modified Ashworth Scale) [Time frame: Baseline (Day 0), Day 15 (end of treatment), and at 1, 3, and 6 months follow-up]
• Change in Health-Related Quality of Life (SF-12) [Time frame: Baseline (Day 0), Day 15 (end of treatment), and at 1, 3, and 6 months follow-up]
• Maintenance of Treatment Effect on Pain (NRS) at Follow-up [Time frame: 1 month, 3 months, and 6 months after end of treatment]
• Incidence of Adverse Events (AEs) and Device-Related Adverse Events (ADEs) [Time frame: From baseline through 6 months follow-up]

Eligibility criteria

Inclusion criteria

• Age ≥ 18 years
• Ischemic or hemorrhagic stroke confirmed by CT or MRI
• Chronic post-stroke phase (≥ 6 months from event)
• Presence of hemiplegic shoulder pain (NRS ≥ 4)
• Preserved cognitive function sufficient to provide informed consent

Exclusion criteria

• Severe cognitive impairment or language deficits (e.g., severe aphasia) that prevent understanding of study procedures or reliable reporting of pain (e.g., inability to complete NRS or questionnaires).
• Severe neglect, apraxia, or disorders of consciousness that interfere with participation in rehabilitation or outcome assessments.
• Pre-existing shoulder pathology of the affected side unrelated to stroke (e.g., full-thickness rotator cuff tear, advanced glenohumeral osteoarthritis, inflammatory arthritis, prior shoulder surgery).
• Fixed shoulder contractures or severe joint deformities limiting passive range of motion and preventing standardized assessment.
• Botulinum toxin injections to shoulder upper limb muscles within the last 3-4 months prior to enrollment .
• Current treatment with other experimental or non-conventional physical therapies for shoulder pain during the study period.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Italy · 1 center

• Università degli studi di Foggia — Foggia

Publications

• Melzack R, Wall PD. Pain mechanisms: a new theory. Science. 1965 Nov 19;150(3699):971-9. doi: 10.1126/science.150.3699.971. No abstract available. PMID 5320816
• Roach KE, Budiman-Mak E, Songsiridej N, Lertratanakul Y. Development of a shoulder pain and disability index. Arthritis Care Res. 1991 Dec;4(4):143-9. PMID 11188601
• Winstein CJ, Stein J, Arena R, Bates B, Cherney LR, Cramer SC, Deruyter F, Eng JJ, Fisher B, Harvey RL, Lang CE, MacKay-Lyons M, Ottenbacher KJ, Pugh S, Reeves MJ, Richards LG, Stiers W, Zorowitz RD; American Heart Association Stroke Council, Council on Cardiovascular and Stroke Nursing, Council on Clinical Cardiology, and Council on Quality of Care and Outcomes Research. Guidelines for Adult Stro PMID 27145936
• Caliandro P, Celletti C, Padua L, Minciotti I, Russo G, Granata G, La Torre G, Granieri E, Camerota F. Focal muscle vibration in the treatment of upper limb spasticity: a pilot randomized controlled trial in patients with chronic stroke. Arch Phys Med Rehabil. 2012 Sep;93(9):1656-61. doi: 10.1016/j.apmr.2012.04.002. Epub 2012 Apr 13. PMID 22507444
• Calabro RS, Naro A, Russo M, Milardi D, Leo A, Filoni S, Trinchera A, Bramanti P. Is two better than one? Muscle vibration plus robotic rehabilitation to improve upper limb spasticity and function: A pilot randomized controlled trial. PLoS One. 2017 Oct 3;12(10):e0185936. doi: 10.1371/journal.pone.0185936. eCollection 2017. PMID 28973024
• Chae J, Mascarenhas D, Yu DT, Kirsteins A, Elovic EP, Flanagan SR, Harvey RL, Zorowitz RD, Fang ZP. Poststroke shoulder pain: its relationship to motor impairment, activity limitation, and quality of life. Arch Phys Med Rehabil. 2007 Mar;88(3):298-301. doi: 10.1016/j.apmr.2006.12.007. PMID 17321820
• Gamble GE, Barberan E, Bowsher D, Tyrrell PJ, Jones AK. Post stroke shoulder pain: more common than previously realized. Eur J Pain. 2000;4(3):313-5. doi: 10.1053/eujp.2000.0192. PMID 10985876
• Murillo N, Valls-Sole J, Vidal J, Opisso E, Medina J, Kumru H. Focal vibration in neurorehabilitation. Eur J Phys Rehabil Med. 2014 Apr;50(2):231-42. PMID 24842220

Identifiers

NCT: NCT07513753 · FoggiaFisiatria_01

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗