For 10 cm. simple and compound records we find all minimum errors are between 160 and 200 beats.
For 1 cm. simple and weighted results there is a scattering of minimum errors from 20 to 200 beats, with a heavy preponderance at 200, and the same is true for the simple-compound series.
The head-movements minimum errors are at 40 beats without exception.
The foot minimum errors are distributed from 20-30 beats for the left foot to 160-180 for the right.
It is thus evident that each group of muscles and each motor centre has its own optimum, and that the conditions of complexity, resistance, etc., influence greatly the accuracy of the periodic movement impulse.
THE MOTOR POWER OF COMPLEXITY
BY C. L. VAUGHAN