Biomedical subjects

R Leanderson

Publications and source records attributed to R Leanderson.

At least 19 recordsLinked to original sources

PubMed1993

Speech in unilateral and bilateral cleft palate patients from Stockholm.

The speech of 84 patients with complete unilateral cleft lip and palate and 19 patients with complete bilateral cleft lip and palate was judged by professional listeners and compared with a control group of 40 noncleft subjects. The unilateral cleft group consisted of two subgroups: one group of 45 patients, who were treated with presurgical orthopedics before primary surgery, and one group of 39 patients, who were not. The speech of the patients and the noncleft subjects was tape recorded and randomly mixed prior to listener judgments. No significant differences in articulation or resonance were found between the subgroups of unilateral cleft patients. The results also indicated that the bilateral cleft patients had poorer speech and needed more speech therapy than the unilateral cleft patients. All cleft patients were found to have poorer speech than the noncleft subjects in spite of considerable speech therapy and complementary surgical treatment. This has resulted in a change in the Stockholm approach toward earlier palatal surgery, tailor-made pharyngeal flap operations, and earlier parental information and treatment of articulatory deviations.

Adolescent↗

PubMed1993

NORAM--an instrument used in the assessment of hypernasality: a clinical investigation.

The speech of 102 patients with complete unilateral and bilateral cleft lip and palate and 40 noncleft subjects was analysed using the NORAM (Nasal Oral Ratio Meter) instrument. The results obtained were compared with the perceptual judgments made by experienced listeners. A significant correlation was found between the NORAM values and the listener judgments. The NORAM instrument can thus be used as a complement to listener judgments in assessing hypernasality. A discussion of the acoustic and phonetic aspects of the differences between the instrumental and perceptual results is presented.

Adolescent↗

PubMed1991

Dentofacial morphology in professional opera singers.

The interaction between muscle function and bone development has been studied mainly in animals. The aim of the present investigation was to study the dentofacial skeleton in individuals with a high degree of activity of muscles associated with the facial skeleton. It was assumed that a professional singer would constitute such an individual. Lateral cephalograms of singers from the Royal Opera Choir in Stockholm were studied and compared with lateral cephalograms of a control group. Significant differences between the singers and controls were found, such as length of mandible, length of maxilla, and increased facial height. The findings could be interpreted as an association between facial muscle hyperactivity and respiratory hyperfunction and dentofacial morphology.

Adult↗

PubMed1988

The effect of voluntary diaphragmatic activation on back lifting.

The effect of increased intraabdominal pressure upon the activation of the erector spinae muscles during back lifting was studied in 10 healthy volunteers. The intraabdominal pressure was increased by voluntary prelifting coactivation of the diaphragm and the abdominal muscles. EMG was recorded with surface electrodes over the diaphragm and the erector spinae, abdominal and intercostal muscles. The EMG signals were rectified and averaged from 20 lifts of 10 kg with and without pressurization to give mean level of activity during 2 s before lifting and during successive angular positions of the trunk during lifting. In 7 of the 10 subjects the pre-lifting coactivation of diaphragm and abdominal muscles reduced erector spinae activity at lift-off and/or during the trunc erecting movement. An increased intraabdominal pressure thus often has an unloading effect on the erector spinae muscle during back lifting.

Abdomen↗

PubMed1987

Role of diaphragmatic activity during singing: a study of transdiaphragmatic pressures.

Esophageal and gastric pressures during singing are measured in four male professional singers performing singing tasks requiring rapid changes of subglottal pressure. Evidence for a consistent use of the diaphragm is found in all subjects. Some subjects punctually activate the diaphragm when there is a need for a rapid decrease of subglottal pressure, such as when singing a falling octave interval, when shifting from a loud to a soft note, to save air during a /p/ explosion, and in performing a trillo involving a repeated switching between glottal adduction and abduction. The first three cases were observed in the beginning of the phrase, presumably over the period that the pressure generated by the passive expiratory recoil forces of the breathing system was higher than the intended subglottal pressure. In addition to this, one subject exhibited a diaphragmatic tonus throughout the entire phrase. The phonatory relevance of a diaphragmatic activity was evaluated in a subsequent experiment. The transdiaphragmatic pressure was displayed on an oscilloscope screen as a visual feedback signal for singers and nonsingers, who performed various phonatory tasks with and without voluntary coactivation of the diaphragm. In most subjects this activity tended to increase the glottal closed/open ratio as well as the amplitude of the glottogram (i.e., the transglottal volume velocity wave-form as determined by inverse filtering). These changes suggest that diaphragmatic coactivation tends to affect phonation. Also, it tended to reduce the formant frequency variability under conditions of changing fundamental frequency suggesting a better stabilization of the vocal tract.

Adult↗

PubMed1983