What does this term PNF mean, dad?” asked my sister. “It is a complex and highly effective physical therapy technique that was developed in the late 1940s and early 1950s. Termed as Proprioceptive Neuromuscular Facilitation, it was developed as a treatment technique for polio
patients with paralysis by Herman Kabat, a neurophysiologist, and two physiotherapists, Margaret Knott and Dorothy Voss. The project was sponsored by Henry Kaiser, an industrialist,” dad said.
The Kabat-Kaiser Institute (KKI), Washington DC, began treating paralysis in 1946. Their whole work was based on Sir Charles Sherrington’s laws on
reciprocal innervations, which states that when a muscle contracts its opposing muscle is inhibited.
“Dad, I can’t understand a thing. Can you explain a bit?” I said.
“To put it simply, whenever the biceps contract, the triceps relaxes to allow
the elbow to bend. This is achieved
by the nerves that control them,” my mom explained.
“The nerve connection is made in such a manner that if one muscle is made to contract, it would inhibit the muscle that opposes the first one so that the movement can occur smoothly. This nerve connection to the opposite group of muscles is called as reciprocal innervations.”
“What has all this got to do with sports and training?” asked my sister.
“It was developed as a technique for patients and the first book on PNF was published in 1956,” dad started. “Facilitated stretching using PNF principles is very useful to gain flexibility. It was used by physiotherapists and athletic trainers in the late 1970s to facilitate stretching in healthy people and various techniques were introduced with different names.”
“One is called Triple S, Scientific Stretching for Sport. Modified PNF was another. As the effectiveness of these techniques spread, sports physicians and physiotherapists, massage therapists, trainers and coaches began using these techniques. The absolute need to
improve performances of athletes lead to the rapid growth of these techniques,” mother intervened.
“How does it work?” sister asked. “How does it improve sports performance?”
“When a muscle contracts or shortens, the length and tension of the muscle is monitored by the brain or the spinal cord. These nerve endings are called
receptors because they receive information from the tissues, muscle, tendon or skin and inform the brain regarding the status of the tissue and its alteration.”
“In this case, length and tension of the muscle is maintained by the proprioceptors, which inform the brain about the intensity and level of contraction of the body.”
“We use our eyes to know where we are or the part of the body. When we play or run, it is not possible to look at every part of the body. To achieve that, the proprioceptors send information to the brain or the spinal cord to inform the muscular status whether it is contracting or stretching. When the muscle is stretched, it stimulates the muscle spindles. Special form of nerve endings that are receptors try to protect the muscle with immediate contraction called as stretch reflex.”
“The inverse stretch reflex happens when the Golgi Tendon Organ (GTO), not an organ but a receptor, in the tendon of a muscle, is stimulated by a strong contraction of a muscle. This stretches the tendon and ultimately forces the muscle to relax. These developments during stretching of a muscle were observed in 1984 who used to hold a stretch for some time to allow the muscle to
relax. It is called as Static Stretch,” dad said.
“What is the difference between PNF and facilitated stretch?” my sister asked.
“Whenever the stretch is
actively done by an athlete, it is called as facilitated stretching. Whenever it
is performed by the trainer or the physio passively, it is
called as PNF stretching,” dad concluded n
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