Age and Individual Differences in Controlled Force Exertion Measured by a Computer-Generated Sinusoidal and Quasi-Random Display

Abstract

This study examined age group and individual differences in controlled force exertion by emulating sinusoidal and quasi-random waveforms in 222 right-handed female adults aged 20 to 86 years. The subjects matched their submaximal grip strength by the dominant hand to changing demand values displayed as either a sinusoidal or a quasi-random waveform appearing on the display of a personal computer. A total of the differences between the demanded value and grip exertion value for 25 seconds was used as an evaluation parameter. The measurements showed a tendency to increase across the age groups in both waveforms. Significant second-order curve regressions were identified, but there was no significant difference in the increase rates of both waveforms. Analysis of variance showed non-significant differences among means of both waveforms in all age groups, and the differences between means in groups of participants over 50 and 20- to 24-year-olds increased in both waveforms. Individual differences were almost the same in both waveforms.

Key words:

• humans
• adult
• hand strength
• psychomotor performance

ACKNOWLEDGMENTS

This study was supported in part by a grant-in-aid for scientific research (project numbers 13780048, 17700476, and 20500506) to Y. Nagasawa from the Ministry of Education, Culture, Sports, Science and Technology of Japan, which the authors gratefully acknowledge.