Changes in masseter muscle trigger points following strain-counterstrain or neuro-muscular technique

• Published in: Journal of bodywork and movement therapies Vol. 13; no. 1; pp. 2 - 10
• Main Authors: Ibáñez-García, Jordi, PT, DO, Alburquerque-Sendín, Francisco, PT, DO, Rodríguez-Blanco, Cleofás, PT, DO, Girao, Didac, PT, DO, Atienza-Meseguer, Albert, PT, DO, Planella-Abella, Sergi, PT, CO, Fernández-de-las Peñas, César, PT, DO, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01-01-2009
• Subjects: Active mouth opening; Adolescent; Adult; Aged; Female; Humans; Jaw - physiology; Latent muscle trigger point; Male; Masseter muscle; Masseter Muscle - physiopathology; Middle Aged; Myofascial Pain Syndromes - physiopathology; Myofascial Pain Syndromes - therapy; Neuromuscular; Pain Threshold - physiology; Physical Medicine and Rehabilitation; Physical Therapy Modalities; Pressure; Pressure pain sensitivity; Strain/counter-strain; Young Adult; Active mouth opening; Strain/counter-strain; Neuromuscular; Latent muscle trigger point; Pressure pain sensitivity; Masseter muscle
• ISSN: 1360-8592; 1532-9283
• DOI: 10.1016/j.jbmt.2008.03.001

Summary The aim of this study was to compare the immediate effects, on pressure pain sensitivity and active mouth opening, following the application of neuromuscular or strain/counter-strain technique in latent myofascial trigger points (MTrPs) in the masseter muscle. Seventy-one subjects, 34 men and 37 women, aged 20–65 years old, participated in this study. Subjects underwent a screening process to establish the presence of MTrPs in the masseter muscle. Subjects were divided randomly into three groups: group A which was treated with a neuromuscular intervention, group B treated with the strain/counter-strain technique, and group C as control group. Each treatment group received a weekly treatment session during 3 consecutive weeks. Outcomes measures were pressure pain thresholds (PPTs), active mouth opening and local pain (visual analogue scale, VAS) elicited by the application of 2.5 kg/cm2 of pressure over the MTrP. They were captured at baseline and 1 week after discharge by an assessor blinded to the treatment allocation of the subject. The ANOVA found a significant group×time interaction ( F =25.3; p <0.001) for changes in PPT, changes in active mouth opening ( F =10.5; p <0.001), and local pain evoked by 2.5 kg/cm2 of pressure ( F =10.1; p <0.001). Within-group effect sizes were large ( d >1) for PPT and mouth opening, and moderate for local pain ( d <0.7, 0.5) in both intervention groups; but small ( d <0.2) for the control group in all outcomes. No significant differences between both intervention groups were found for any outcome ( p >0.8). Our results suggest that neuromuscular or strain/counter-strain technique might be employed in the management of latent MTrPs in the masseter muscle.