Analysis of body posture during vocal effort

Antoine Giovanni, Laetitia Papon, Christine Assaiante, Leslie Akl, François Le Huche

Objective: To assess segmental and global body posture modifications and mainly increased tension of body posture muscles during vocal effort
Design: Experimental study
Methods: Global tension was assessed with a plat-form designed to detect variations of the center of gravity G. The reliability of this device to detect increased postural muscular activity has been tested first by different means and mainly by comparison between control subjects at rest and with a 3kg weight in hands. Segmental modifications were assessed using a 3D numerical device based upon video detection and reconstruction (Elite®)
Experiment was conducted on control subjects at rest, during quiet phonation, during phonation in an ambient noise at 90 Db, and in “emergency” phonation not anticipated by the subjects
Results: Our result show that in case of anticipated loud phonation induced by ambient noise, there is an increased global muscular tension compatible with the concepts of muscle tension dysphonia but no detectable modifications of global body posture
In case of “emergency” phonation, there is a dramatic change of body posture with mainly a forward head projection, and modifications of acoustic properties of voice
Discussion: Concepts of muscular tension dysphonia and relationship between posture, voice and feelings of the subjects about the estimated need and emergency of vocal effort are discussed in order to replace vocal effort not only as the result of an excessive vocal loading but as well as an emotionally-marked behavior

Antoine Giovanni MD, PhD (Laboratoire d’Audio-Phonologie Expérimentale et Clinique –Marseille, France)
Laetitia Papon, Speech Therapist (Laboratoire d’Audio-Phonologie Expérimentale et Clinique –Marseille, France)
Christine Assaiante (CNRS, Marseille, France)
Leslie Akl, Speech Therapist (Beyrouth – Lebanon)
François Le Huche, Phoniatrician (Paris, France)
Corresponding author:
Antoine Giovanni, Federation ORL CHU Timone
13385 Marseille cedex 5
France
Tel +33 4 91 38 60 69 Fax +33 4 91 38 74 54