Influence of traction therapy of the cervical spine on the distribution of harmonics in the voice as well as the intensity and length of phonation

Background
Contemporary physiotherapeutic techniques and methods could be useful in changing the approach to teaching correct phonation in people with different vocal experience. A physiotherapist can use stimulating techniques, improving the lower rib breathing in a vocalist, using thoracic expansion techniques, diaphragm decompression or manual massage, as well as spinal and rib mobilization. Moreover, many modalities for temporomandibular joint (TMJ) therapy can be useful for working with vocalists. Aims: The aim of the study was to find the relationship between the distribution of harmonics, sound intensity, and phonation length and the use of the cervical spine traction technique in people with different vocal experience. Material and methods: The study in a group of 35 people was carried out at the Physioteam clinic in Wroclaw (Poland). First, the respondent was asked to complete a questionnaire regarding his experience and aspects of vocal education. Then the measure was conducted from the distance of 30 cm from the mouth to the membrane and took a sound sample on C-sound (130 Hz) for men and (260 Hz) for women. After recording the sample, we moved on to traction. Traction was performed on a massage table, in the supine position, by one physiotherapist for all persons from the study. The technique was performed for 2 minutes in each of the 3 positions: the head is slightly extended and the neck is flexed, the head and neck in right-sided rotation, and the head and neck in left-sided rotation.

Aims
The aim of the study was to find the relationship between the distribution of harmonics, sound intensity, and phonation length and the use of the cervical spine traction technique in people with different vocal experience.

Material and methods
The study in a group of 35 people was carried out at the Physioteam clinic in Wroclaw (Poland). First, the respondent was asked to complete a questionnaire regarding his experience and aspects of vocal education. Then the measure was conducted from the distance of 30 cm from the mouth to the membrane and took a sound sample on C-sound (130 Hz) for men and (260 Hz) for women. After recording the sample, we moved on to traction. Traction was performed on a massage table, in the supine position, by one physiotherapist for all persons from the study. The technique was performed for 2 minutes in each of the 3 positions: the head is slightly extended and the neck is flexed, the head and neck in right-sided rotation, and the head and neck in left-sided rotation.

Results
The study showed that for the entire study group of singers, the average length of the sample was longer at measurement 2, i.e., after applying the cervical spine traction technique, than before performing the technique. This is a significant change that can be noticed in the study group after performing the technique. The Root Mean Square (RMS) parameter did not change significantly, while the spectrum centroid decreased at measurement

Conclusions
Based on the results, the following conclusions were drawn: the technique of traction of the cervical spine significantly influences the phonation length in a group of experienced singers, the technique of traction of the cervical spine decreased the spectrum centroid in the whole study group, this technique is most applicable to an experienced group of singers, physiotherapy is a field which, with the help of its tools, can change the approach to teaching correct phonation.