title: Comparison of upper and lower lip muscle activity between stutterers and fluent speakers.
abstract: OBJECTIVE
  There is a widespread clinical view that stuttering is associated with high levels of muscles activity. The proposal of this research was to compare stutterers and fluent speakers with respect to the electromyographic activity of the upper and lower lip muscles.
  
  
  METHODS
  Ten individuals who stutter and 10 fluent speakers (control group) paired by gender and age were studied (mean age: 13.4 years). Groups were defined by the speech sample analysis of the ABFW-Language Test. A K6-I EMG (Myo-tronics Co., Seattle, WA, USA) with double disposable silver electrodes (Duotrodes, Myo-tronics Co., Seattle, WA) being used in order to analyze lip muscle activity. The clinical conditions investigated were movements during speech, orofacial non-speech tasks, and rest. Electromyographic data were normalized by lip pursing activity. The non-parametric Mann-Whitney test was used for the comparison of speech fluency profile, and the Student t-test for independent samples for group comparison regarding electromyographic data.
  
  
  RESULTS
  There was a statistically significant difference between groups regarding speech fluency profile and upper lip activity in the following conditions: lip lateralization to the right and to the left and rest before exercises (P<0.05). There was no significant difference between groups regarding lower lip activity (P>0.05).
  
  
  CONCLUSIONS
  The EMG activity of the upper lip muscle in the group with stuttering was significantly lower than in the control group in some of the clinical conditions analyzed. There was no significant difference between groups regarding the lower lip muscle. The subjects who stutter did not present higher levels of muscle activity in lip muscles than fluent speakers.
authors.affiliation: Faculty of Medicine of Ribeirão Preto of the University of São Paulo, Department of Otorhinolaryngology, Ophthalmology and Head and Neck Surgery, Ribeirão Preto 14049-900, SP, Brazil. cfelicio@fmrp.usp.br
authors.forename: Cláudia Maria
authors.initials: CM
authors.lastname: de Felício
authors.forename: Rosana Luiza Rodrigues Gomes
authors.initials: RL
authors.lastname: Freitas
authors.forename: Mathias
authors.initials: M
authors.lastname: Vitti
authors.forename: Simone Cecilio Hallak
authors.initials: SC
authors.lastname: Regalo
mesh_terms: D000293:Adolescent; D002648:Child; D004576:Electromyography; D005152:Facial Muscles / Q000294:innervation* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008046:Lip / Q000294:innervation* / Q000503:physiopathology*; D008297:Male; D012720:Severity of Illness Index; D013060:Speech / Q000502:physiology*; D013342:Stuttering / Q000175:diagnosis* / Q000503:physiopathology*