The purpose of this study was to analyze the effect of age (4 age groups), physical fitness level (3 levels), and movement segment (application and release) on manual force control as measured by the Trace and Track Task. The subjects were 4 age groups of females: 20s (n = 33, 22.67 ± 2.63), 40s (n = 30, 44.27 ± 2.53), 60s (n = 27 66.85 ± 1.77), and 70s (n = 30, 74.23 ± 3.25). They were tested with the Trace and Track Task (manual force quantification system apparatus; University of Texas at Austin), and a physical fitness test (hand strength, 5-min step test, flexibility, % body fat). Also all age groups were subdivided into 3 physical fitness levels according to physical fitness score (sum of T score on respective physical fitness tests). For data analysis (using SPSSWIN 12.0 program and Excel), the mean and standard deviation scores were calculated and T score, 2-way MANOVA, 2-way ANOVA, paired t test, and Scheffé post hoc tests were used.
The results of this study were as follows: First, younger females were significantly faster and more accurate than older females on the manual force control task (Trace and Track Task), and a clear age effect was also observed on the much more difficult Track Task. Second, release was significantly more difficult than application on manual force control in all age groups, and age effects were more distinct on the release segment. Third, fitness level did not have an influence on the manual force control task. In conclusion, increased age was linked to more difficulty with manual force control and also showed significant negative effects on a challenging tracking task. However, enhanced physical fitness did not seem to have an effect on manual force control.