Body Position Effects on EMG Activity of Sternocleidomastoid and Masseter Muscles in Patients with Myogenic Cranio-Cervical-Mandibular Dysfunction

Palazzi, Carmen; Miralles, Rodolfo; Soto, Miguel Angel; Santander, Hugo; Zúñiga, Claudia; Moya, Hugo

doi:10.1080/08869634.1996.11745969

Cited by 20 publications

(16 citation statements)

References 25 publications

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“…This effect could be explained considering the strict relationship between jaw and head–neck systems (20), which show coordinate motion patterns during their functional activities (36). Experimental modifications of body position (13, 16, 17, 37–39) as well as of occlusal surfaces and dental contacts (2, 8–10, 15, 16) can significantly modify SCM muscle contraction patterns. In contrast, in the present study no artificial modifications of the occlusal relationships were made, and only natural dental contacts and maxillo‐mandibular relationships were assessed.…”

Section: Discussionmentioning

confidence: 99%

The influence of occlusion on jaw and neck muscle activity: a surface EMG study in healthy young adults

Ferrario¹,

Tartaglia²,

Galletta³

et al. 2006

J of Oral Rehabilitation

159

218

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The electromyographic (EMG) characteristics of masseter, temporalis and sternocleidomastoid (SCM) muscles during maximum voluntary teeth clench were assessed in 27 male and 35 female healthy young adults. Subjects were divided into two groups: (i) 'complete' Angle Class I (bilateral, symmetric canine and molar Class I relationships), and (ii) 'partial' Angle Class I (one to three canine/molar Class I relationships, the remaining relationships were Class II or Class III). On average, standardized muscular symmetry ranged 80.7-87.9%. During maximum voluntary teeth clench, average co-contraction of SCM muscle was 13.7-23.5% of its maximum contraction. On average, all torque coefficients (potential lateral displacing component) were >90%, while all antero-posterior coefficients (relative activities of masseter and temporalis muscles) were >85%. The average integrated areas of the masseter and temporalis EMG potentials over time ranged 87.4-106.8 muV/muV s%. Standardized contractile muscular activities did not differ between 'complete' and 'partial' Angle Class I, and between sexes (two-way analysis of variance). A trend toward a larger intragroup variability in EMG indices was observed in the subjects with 'partial' Angle Class I than in those with 'complete' Angle Class I (significant difference for the temporalis muscle symmetry, P = 0.013, analysis of variance). In conclusion, the presence of a complete or partial Angle occlusal Class I did not seem to influence the standardized contractile activities of masseter, temporalis and SCM muscles during a maximum voluntary clench. Subjects with a 'complete' Angle Class I were somewhat a more homogenous group than subjects with 'partial' Angle Class I.

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Section: Discussionmentioning

confidence: 99%

The influence of occlusion on jaw and neck muscle activity: a surface EMG study in healthy young adults

Ferrario¹,

Tartaglia²,

Galletta³

et al. 2006

J of Oral Rehabilitation

159

218

View full text Add to dashboard Cite

show abstract

“…Functional coupling (synchronous facilitation of motor activity) of the mandibular and cervical-cranial locomotor systems is exemplified by the EMG observation that, during clenching of the teeth in centric occlusion and regardless of body position (vertical/ horizontal), the SCM and masseter muscles show co-activation: increasing motor activation of the masseter muscles is associated with increasing motor activation of the SCM muscles, to the effect that when the masseter muscles show maximum (100%) activity the SCM muscles show a geometric mean of about 10% of their maximum activity (Clark et al, 1993;Palazzi et al, 1996;Ormeno et al, 1997).…”

Section: Discussionmentioning

confidence: 99%

Electrognathographic and electromyographic observations on jaw depression during neck extension

McKay¹,

Christensen²

1999

J of Oral Rehabilitation

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Albeit never substantiated through experimental and clinical evidence, the theoretical linchpin of the mechanics of a so-called whiplash injury of the temporomandibular joint (TMJ) is the postulate that a pre-existing depressor force (continual anchoring force), generated by the anterior suprahyoid (SH) muscles, will always act on the mandible and cause traumatic mouth opening (anterior acceleration of the TMJ condyles) when the neck is extended (posterior acceleration of the head). To test aspects of this postulate, six subjects assumed the positions of neutral (0 degrees ), medium (32 degrees ) and maximum (58 degrees ) neck extension while the mandible was in its postural positions of rest and light centric occlusion. By means of surface electromyography, it was shown that the relative contractile activities of the anterior SH muscles never exceeded 7.3% of the contractile activity required to anchor the mandible in a position of maximum depression. By means of electrognathography, it was shown that the maxillary and mandibular incisors were never separated by more than 2.6 mm during neutral, medium, and maximum extension of the neck. In other words, during neck extensions there was no evidence of a continual or induced voluntary or involuntary depressor force that would and could anchor the mandible in a position of traumatic mouth opening. Accordingly, and in agreement with other biophysical and biomedical evidence, it was concluded that there is no foundation for the pseudoscientific speculations and unsubstantiated opinions offered in support of a concept and diagnosis of a so-called TMJ whiplash injury. Additionally, this study found co-activation of cervical flexor muscles and mandibular elevator as well as depressor muscles.

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“…Palazzi et al (8) found that symptoms in the sternocleidomastoid and masseter muscles were correlated with body position in subjects with myogenic cranio-cervical mandibular dysfunction. Several authors have hypothesized that posture training might be a positive impact on the masticatory musculature (9,10).…”

Section: Introductionmentioning

confidence: 99%

The Immediate Effect of Hamstring Muscle Stretching in Subjects' Trigger Points in the Masseter Muscle

Fernández‐de‐las‐Peñas

Carratalá-Tejada

Luna-Oliva

et al. 2006

Journal of Musculoskeletal Pain

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Objective: The aim of this study was to analyze the immediate effect of post-isometric stretching of the hamstring muscles on active mouth opening and pressure pain threshold [PPT] in subjects presenting with trigger points [TrPs] in the masseter muscle.Methods: Fifty subjects, 31 men and 19 women, aged 24 to 57 years old, participated in this study. Subjects underwent a screening process to establish the presence of TrPs in the masseter muscle as described by Simons et al. (1). Subjects were divided randomly into two groups. Group A was treated with a post-isometric relaxation technique to the hamstring muscle ipsi-lateral to the masseter TrP and group B was a control group, without any type of intervention. The outcome measures were the PPTs at the TrP and maximum mouth opening. These were assessed pre-treatment and two minutes post-treatment by an examiner blinded to the treatment allocation of the subject.Results: Within-group changes showed a significant improvement in the PPT [P = 0.01] and in active mouth opening [P < 0.01] in the treatment group, but not in the control group [P < 0.3]. Pre-post effect size was large in the treated group [d > 1]. The experimental group obtained a greater improvement than the control group in both outcomes [P < 0.01 for PPT, P = 0.02 for active mouth opening]. A positive correlation [r = 0.46; P = 0.01] was found between the improvement in the PPT and the improvement in mouth opening in the experimental group, but not in the control group. Within the experimental group, active TrPs showed a greater improvement in both outcomes than latent TrPs.Conclusions: The present study demonstrated an increase in active mouth opening and a decrease in TrP sensitivity in the masseter muscle in response to the stretch of the hamstring muscles. The hypothesis of a functional relationship between the masticatory and hamstring muscles is ]. Preliminary results of this study were presented as a communication in the XIII Jornadas de Fisioterapia: "Fisioterapia en la articulación temporomandibular." Escuela Universitaria de la ONCE, Madrid,

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Body Position Effects on EMG Activity of Sternocleidomastoid and Masseter Muscles in Patients with Myogenic Cranio-Cervical-Mandibular Dysfunction

Cited by 20 publications

References 25 publications

The influence of occlusion on jaw and neck muscle activity: a surface EMG study in healthy young adults

The influence of occlusion on jaw and neck muscle activity: a surface EMG study in healthy young adults

Electrognathographic and electromyographic observations on jaw depression during neck extension

The Immediate Effect of Hamstring Muscle Stretching in Subjects' Trigger Points in the Masseter Muscle

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