Postural stability and muscle activation as a function of measured voice quality in student singers.

Decoster, W., Romagnoli, T., Staes, F., Van Deun, S.

Singing requires a high level of muscle coordination to initiate and control phonation. Although student singers are trained to use their skeletal muscles in favor of appropriate breathing and breath support, phonation, resonance and articulation, there apparently still remains a great variability in sequence of initial contraction, in stability, degree of contraction, in speed of alternation of contraction and relaxation and in coordination. In search for a description of this muscle activation, we tried to set up a measuring device for postural stability and muscle use, simultaneous with video recordings and voice quality measurements.
Ten student singers who reached different levels of singing education are involved in this study. All of them get singing lessons twice a week at the Lemmensinstituut, a Belgian high school for professional education in music.
As a base line measurement students are asked to stand still on a force plate to measure their postural stability. The displacement of the center of pressure is measured. Superficial electromyography of the following muscles was bilaterally recorded during several singing tasks: m scalenus medius, m trapezius pars descendens, m transversus abdominis, m rectus abdominis. Simultaneously, the voice is registered digitally and, in a split screen with frontal and side view, the body is video taped.
In relation to the visual evaluation of the body movement we report on our findings about the research question how muscle use and vocal efficiency are related and how mastery of the singing technique can accurately be described in terms of muscle use and stability of the body.

Decoster, W.*, Romagnoli, T.*, Staes, F.°, Van Deun, S°.
* Speech Language Pathology and Audiology
Labo ExpORL - dept. Neurosciences
Herestraat 49, O&N2, 721
B - 3000 Leuven
Tel: +32 (0)16 33 04 84 fax: +32 (0)16 33 04 86
Wivine.Decoster@med.kuleuven.be

° Research Centre for Musculoskeletal Rehabilitation
Dept. Revalidation Sciences
Tervuursevest 101, 1501
B - 3001 Leuven
tel: +32 (0)16 32 91 25 fax: +32 (0) 16 32 91 97
Filip.Staes@faber.kuleuven.be