The effect of PNF position of the upper extremity on rapid knee extension.

Premotor time (PMT) and maximum tension (Fmax) produced by isometric contraction of the left and the right quadriceps femoris for rapid knee extension were examined in 10 normal male subjects at two positions of the left upper extremity, neutral and facilitating position for the triceps brachii. Compared to the neutral position, PMT of the both sides decreased and Fmax increased at the facilitating position, while the contraction time did not change. It is assumed that the facilitating position brings about generalized activation of the central nervous system resulting in behavioral alertness.