Restrições espaciais no controle motor de movimentos rápidos e precisos/Spatial constraints in the motor control of speed and accurate movements

The effect of spatial constraints (distance and target width) over the motor control strategies of speed and accurate movement was analyzed. Twenty men (20 years old-26 years old) performed the Fitts' task simulated in a computer. The Discrete Aiming Task (v. 1.0) provided the kinematic analysis of the mouse cursor and the index of manipulation difficulties (1 bit to 5 bits). Increased distance provided great TM, acceleration phase, deceleration phase, and velocity, but without changing accuracy. Accuracy maintenance was explained by the maintenance of acceleration and deceleration phases' strategy. Decreased target width provided greater TM and deceleration phase and a reduction of the peak velocity, which allowed better accuracy even when average velocity was held constant. Different control strategies were performed when functioning given the spatial constraints as manipulated by the distance and target width.