Ability to Coordinate Exertion of Force by the Dominant Hand: Comparisons among University Students and 65- to 78-Year-Old Men and Women

The purposes of this study were to examine the characteristics of ability to coordinate exertion of force in 60 healthy older people (30 men, 30 women) from the viewpoint of sex differences and to compare their performance with those of 60 healthy university students (30 men, 30 women). The test of ability to coordinate exertion of force was conducted by having the subject fit the exertion value of grip strength to a changing demand value appearing on the display of a personal computer (using a bar chart-description form). The changes in the demand value were tracked. The variable estimating ability to coordinate exertion of force was the total sum of the differences between demand and the produced grip strength induced by time lapses. The ability to coordinate exertion of force in the older subjects was inferior to that of the younger subjects, and large individual differences were observed. Unlike the younger subjects, the means of the ability to coordinate exertion of force of the older subjects significantly decreased between trials. The ability to coordinate exertion of force of the older women was significantly inferior to that of the older men, but the means of the measurements among three trials shows a similar tendency to decrease in both sexes.