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Effectiveness of low-intensity laser on pain in patients with supraspinatus tendinopathy: A triple-blind randomized controlled trial
Jorge Velázquez Saornil, María del Rosario Ferreira-Sánchez, Lucía Rodríguez Martín, Zacarías Sánchez Milá, Roberto González Raja, Catalina Loaiciga Espeleta, Carlos Romero-Morales, David Briz Benito, Isaac Rodríguez Fragua
Isaac Rodríguez Fragua, David Briz Benito, Catalina Loaiciga Espeleta, Roberto González Raja, Jorge Velázquez Saornil, UPSALUD Group, Fisioterapia, Universidad Pontificia de Salamanca, Salamanca 37002, Spain
Carlos Romero-Morales, Faculty of Sport Sciences, Universidad Europea de Madrid, Villaviciosa de Odón; Madrid 28023, Spain
Zacarías Sánchez Milá, NEUMUSK Group, Department of Physiotherapy, Universidad Católica de Ávila, Ávila 05005, Spain
Lucía Rodríguez Martín, Fisioterapia, Clínica Vallesur, Ávila 05002, Spain
María del Rosario Ferreira-Sánchez, Fisioterapia, Universidad Católica de Ávila, Ávila 05005, Spain
Co-corresponding authors: Zacarías Sánchez Milá and Jorge Velázquez Saornil.
Author contributions: Rodríguez Fragua I and Romero-Morales C wrote the document in its initial format and the final draft; Rodríguez Fragua I and Briz Benito D analyzed the data and designed the figures; Velázquez Saornil J, Loaiciga Espeleta C, Briz Benito D and Rodríguez Martín L conceptualized and designed the research; Sánchez Milá Z, Ferreira-Sánchez MDR, González Raja R, and Rodríguez Martín L executed the study and collected most of the data; Rodríguez Fragua I, Rodríguez Martín L, and González Raja R assessed the laser techniques and were responsible for maintaining and checking the blindings at all times; Loaiciga Espeleta C, administred treatments and carried out the interventions as described in the study design; Romero-Morales C, Sánchez Milá Z, and Velázquez Saornil J provided expertise in the study design and components of the article; all authors contributed to drafting the article and revised the manuscript for important intellectual content; and all authors had access to the study data and reviewed and approved the final manuscript. Two corresponding authors are proposed because they share the primary responsibility for the study in complementary areas. Velázquez Saornil J has led the methodological design, trial registration, statistical analysis and data management, while Sánchez Milá Z has been the clinical principal investigator, responsible for recruitment, participant follow-up and intervention safety. Both guarantee access to data, response to editorial and reader consultations, and the scientific integrity of the work, so they are considered co-responsible for the manuscript.
Institutional review board statement: Approved by the Ethics Committee of the University Hospital of Móstoles with registration code CEI 2024/021.
Clinical trial registration statement: Clinical trial registration on the clinicaltrial.gov website with number NCT07261449.
Informed consent statement: The informed consent was obtained from all participants before data collection began.
Conflict-of-interest statement: All authors declare that they have no conflict of interest to disclose.
CONSORT 2010 statement: The authors have read the CONSORT 2010 statement, and the manuscript was prepared and revised according to the CONSORT 2010 statement.
Data sharing statement: The data are available upon request from the corresponding author.
Corresponding author: Jorge Velázquez Saornil, PhD, Fisioterapia, Universidad Pontificia de Salamanca, C/Compañía, 5, Salamanca 37002, Spain.
jvelazquezsa@upsa.es
Received: February 11, 2026
Revised: March 6, 2026
Accepted: March 24, 2026
Published online: June 18, 2026
Processing time: 126 Days and 16.9 Hours
BACKGROUND
Tendinopathy is an inflammatory process that occurs in and around the tendon when both are affected by a specific injury. The supraspinatus muscle is one of the most common causes of shoulder pain.
AIM
To test the effectiveness of laser treatment in reducing pain, improving mobility, quality of life and pressure pain thresholds (PPT) in patients with supraspinatus tendinopathy.
METHODS
A randomised controlled clinical trial was conducted in which a physiotherapeutic intervention with a therapeutic laser was performed for four weeks to observe the influence of supraspinatus tendinopathy in the shoulder on pain. In addition, a triple-blind study was conducted, in which the physiotherapist performing the intervention was blinded, as were the patients receiving the treatment and the person interpreting the study results. A sample of 80 patients was recruited and randomly divided into two groups: An experimental group and a control group. Laser therapy was applied to the first group, and a placebo was applied to the second group.
RESULTS
Eighty participants were randomized to a therapeutic laser group (n = 40) or a placebo group (n = 40), with no baseline differences in demographic or clinical variables. Post-intervention analyses revealed significantly greater improvements in the laser group compared with placebo for pain intensity, muscle strength, and active shoulder range of motion in flexion, extension, abduction, and external rotation (P < 0.05). No between-group differences were observed for PPT, adduction, or internal rotation. Within-group analyses showed significant improvements in all clinical variables only in the laser group. Repeated-measures the Analysis of Variance demonstrated a significant time × group interaction for Disability of Arm, Shoulder, and Hand scores (P < 0.001), indicating superior and sustained functional improvement in the laser group up to three months post-intervention.
CONCLUSION
The therapeutic laser therapy produced superior and sustained improvements in pain, strength, shoulder mobility, and functional outcomes compared with placebo, supporting its effectiveness as an adjunct treatment.
Core Tip: This triple-blind randomized controlled trial demonstrates that therapeutic laser therapy produces meaningful and lasting benefits in patients with supraspinatus tendinopathy by reducing shoulder pain and enhancing joint mobility. The intervention also leads to relevant gains in rotator cuff muscle strength and overall shoulder function, facilitating better performance in daily and overhead activities. These improvements are not explained by placebo responses alone, supporting therapeutic laser as an effective, evidence-based option within a multimodal rehabilitation approach for this common shoulder disorder.
