Interferential laser therapy in the treatment of shoulder pain and disability from musculoskeletal pathologies: a randomised comparative study

• Published in: Physiotherapy 2012-06, Vol.98 (2), p.143-150
• Main Authors: Montes-Molina, Ramón, Prieto-Baquero, Almudena, Martínez-Rodríguez, Maria E, Romojaro-Rodríguez, Ana B, Gallego-Méndez, Vanesa, Martínez-Ruiz, Fidel
• Format: Article
• Language: English
• Subjects: Clinical trials; Disability; Disability Evaluation; Female; Handicapped; Hospitals; Humans; Interferential laser therapy; Joints; Laser therapy; Lasers; Low-level laser therapy; Low-Level Light Therapy - methods; Male; Middle Aged; Musculoskeletal pain; Musculoskeletal Pain - rehabilitation; Musculoskeletal Pain - therapy; Pain; Pain Measurement; Physical Medicine and Rehabilitation; Physical therapy; Range of Motion, Articular; Rehabilitation; Shoulder disability; Shoulder pain; Shoulder Pain - rehabilitation; Shoulder Pain - therapy; Shoulders; Single-Blind Method; Therapy
• ISSN: 0031-9406; 1873-1465
• DOI: 10.1016/j.physio.2011.02.007

Abstract Background Interference is an important feature of the waves. When two or more in phase light waves meet, a new and reinforced wave is generated. Shoulder pain is a common clinical problem and laser is one of the treatments frequently used to relieve it. Objective To test the safety of interferential laser therapy generated by two independent low level lasers and compare its effectiveness with conventional single laser therapy in the reduction of shoulder musculoskeletal pain and associated disability. Design Randomised and single-blind controlled clinical trial. Setting Physiotherapy Unit and Rehabilitation Department of Ramon y Cajal University Hospital (Madrid). Participants 200 patients with shoulder musculoskeletal pain were randomly assigned in two groups, 100 people each. Interventions Group I, experimental (n=100) received interferential laser, placing two probes opposite each other over the shoulder joint. Group II, control (n=100) received conventional laser therapy, using a single probe along with a second inactive dummy probe. Lasers used were GaAlAs diode (810 nm, 100 mW), in continuous emission. Laser was applied in contact mode through ten sessions, on 5 shoulder points (7 Joules/point) per session. Main Outcome Measures Visual Analogue Scale (VAS) score and Shoulder Pain Disability index (SPADI), recorded before and after laser treatment. Results There were no differences between both groups in the reduction of pain, either assessed by VAS scale (median difference=0, 95% CI of the difference =-.6 to .5, p=0.81) or SPADI index (median difference = .4, 95% CI of the difference =-2.9 to 3.8, p=0.80), using the Mann-Whitney U-test. Comparison between the scores recorded before and after the treatment, within each group, showed significant differences for VAS during movement (median difference=3, 95% CI of the difference =2.07 to 4, p