[Effect of linear, impact and vibration accelerations on the accuracy of performance of force load programs by an...

The factors that influence the accuracy with which motor commands are actualized were investigated. The study concentrated on linear acceleration of different sign (produced by rocking a heavy metal platform), vibration at a frequency of about 23 Hz, and impact acceleration resulting from the platform or the rotating chair being suddenly stopped. The force applied to hand sticks or foot levers was recorded by means of electromechanical sensors. It was demonstrated that smoothly varying and in particular impact acceleration caused normal men to subjectively underestimate their own muscle efforts. As a rule, this led to a greater than prescribed strength applied. It is very important to note that acceleration acting from right to left or from left to right (in the frontal plane) produced nonsymmetric pressure by the right and left limbs.