1989 年 33 巻 2 号 p. 457-465
In order to investigate tongue skill, upward and downward tongue movements with two constant frequencies were observed by using an ultrasound system in young and elderly adults. Upward and downward movements in accordance with a metronome were recorded by ultrasono recorder from the Motion-mode.
Movement rhythm andmovement velocity of the tongue were compaired in the two age groups.
The main findings were:
1. The ultrasound system with 5 MHz ultrasound convex transducer and Motion-mode observation produced clear traces of the tongue surfaces in the sagital plane during upward and downward movements.
2. Upward and downward movement rhythms in the elderly were more irregular than those of young adults.
3. Velocity of tongue upward and downward movements were statisticallydecreased in the elderly (p>0.01). Velocity did not clearly change if themovement speed was different in the elderly.
Results of this study revealed that oral motor behaviour in the elderly differed from that of young adults.