Constraint path movements require careful control of objects that are being moved, to achieve speed and accuracy. They are important forms of tasks in everyday life and in industrial environments. Until recently, for unknown reasons, little consideration has been given to generalizing Drury’s important model (1971), which is known to govern visually controlled constraint path movements. During the current experiments, the effect of path movement angle on movement time has been investigated. Drury’s (1971) model has been generalized to account for the effect of path angle. Further, the effect of path amplitude on visually controlled and ballistically performed constraint path movements has been investigated and quantified....[ Read more ]

Constraint path movements require careful control of objects that are being moved, to achieve speed and accuracy. They are important forms of tasks in everyday life and in industrial environments. Until recently, for unknown reasons, little consideration has been given to generalizing Drury’s important model (1971), which is known to govern visually controlled constraint path movements. During the current experiments, the effect of path movement angle on movement time has been investigated. Drury’s (1971) model has been generalized to account for the effect of path angle. Further, the effect of path amplitude on visually controlled and ballistically performed constraint path movements has been investigated and quantified.

Results showed a significant effect (p<0.001) of path angle on movement time. Furthermore, multiplicative relationship was identified between movement time and A/W ratios, for the angles tested. Movement time had an approximate sinusoidal relationship with path angle and was symmetrical about the 0°-180° axis. Effect of path amplitude has been shown to be significant (p<0.001) yet small and was identified in the speed form of Drury’s model, which was not apparent in movement time form. Further, a movement time variance method has been proposed to define the boundaries of visually controlled, transitional and ballistic movements, while a polar relationship has been identified between movement time and A/W ratios, in the transitional region.

At low A/W values, movements were ballistic where Drury’s model (1971) doesn’t hold. Path width was irrelevant (p>0.05) for ballistic movement times while a linear relationship seems to hold between ballistic movement time and path amplitude to the power of 0.5, irrespective of angle. A sinusoidal model has been proposed to account for the effect of path angle for ballistic movement times. Moreover, limits on visually controlled constraint path movements have been defined using speed vs. path width curves.