Stretching the truth. A review of the literature on muscle stretching.

The title of this review can be interpreted in two ways, reflecting the stage of development of knowledge regarding the neuromuscular events during short duration stretching of normal muscle. If current scientific theories are accepted as the truth, then the truth needs to be stretched a little to explain the findings from clinical trials in normal human subjects. Recent studies have shown quite high levels of electromyographic (EMG) activity in muscle undergoing stretching and also that proprioceptive neuromuscular facilitation (PNF) relaxation techniques actually increase EMG activity, yet paradoxically result in greater gains in range than those obtained from passive stretching techniques. These findings limit the somewhat simplistic notion of muscle relaxation during stretching, to achieve intramuscular connective tissue elongation.