The effects of age and gender on lip function in a normal adult population

Abstract

One hundred and sixty-four healthy male and female adults were assessed on nonspeech and speech tasks to determine the effects of age and gender on lip function. The study was designed to provide normative data for lip function in three adult age groups: young (18–30 years), middle age (31–55 years), and older (56–79 years) adults. A miniature transducer was used to record interlabial pressures for the following: maximum lip pressure, sustained maximum and submaximal lip pressures, fine lip force control (10% of maximum), repetition of maximum lip pressures, maximum rate of repetitive lip pressures (number of repetitions and mean pressure over total number of repetitions), and production of /p/. Results revealed that males demonstrated greater interlabial pressures than females during all maximum effort tasks and during production of /p/. Gender effects were not evident for fine lip force control, sustained submaximal lip pressures, or rate of repetitive lip movements. Lip function was found to decline as a function of age for fine lip force control, and for rate and mean pressure during rapid repetitive lip movements. Age effects were not evident for maximum lip pressure, sustained maximum and submaximal lip pressures, mean pressure across 10 repetitions, or during speech activities. The results are discussed in relation to the effects of age and gender on muscle function. The study has provided a normative database of lip function for comparison with disordered populations.