While stretching-induced deficit and bilateral deficits have
been observed during isometric force production and have
been measured with EMG, not many studies have evaluated
the effects of PNF stretching on force production and EMG
activity, and it is not known whether there is an additive effect
of these two deficits. Because the real causes of both deficits
are not known, it is uncertain whether they employ the same
inhibitory pathway or rely on different mechanisms.