T'ai Chi • Kung Fu • Kids Martial Arts • Shop

Letter from Jim Buell on Stretching and PNF

Part 1

Sifu Hau,

Today in the green sash class you amazed me when you were casually showing Glenda how to increase her hamstring stretch.

There were two relaxation methods you demonstrated that are both quite effective. The first, Proprioceptive Neuromuscular Facilitation (PNF), was the act of trying to flex the already stretched muscle and then relaxing it. This doesn't seem to be well known, at least nobody I ever train with has ever heard of it.

The second, relaxation breathing, is better known, but rarely does anyone know WHY it works. The first time I tried PNF it added nearly a foot to my hamstring stretch. I'm using both methods, among others, to drag my creaky body, kicking and screaming, back into some kind of shape.

As we move about all day, every day, our nervous system maintains a set of
ranges of motion (ROM) that our muscles can comfortably accommodate. Our nervous system automatically tenses muscles into a stretch reflex when they
are stretched into unfamiliar positions. It is that set of 'firmware' that we fight against when we try to stretch into new positions. PNF momentarily bypasses this firmware via an element in the spinal cord called a Renshaw Cell. When the stretched muscle is flexed, the Renshaw Cell switches off the stretch reflex in order not to overcompensate. It takes a few seconds for the stretch reflex to recover after the Renshaw Cell stops bypassing it (when we stop the flexing), during which time the stretched member can move farther into stretch. Once held in that extended stretch position until comfort returns, gradually the stretch reflex gets reprogrammed into the farther stretched position.

An interesting fallout from this notion is the idea that strengthening the muscles can add flexibility. If part of the reason for the stretch reflex is weakness of the muscles that support a joint, increasing their strength can help reprogram the stretch reflex to a farther stretched position. This goes against conventional wisdom that strength training decreases flexibility. I'd go on about relaxation breathing, but I'm sure you understand that better than I.

These are really pearls of wisdom that I'm not sure were sufficiently appreciated by your audience. At one of my stateside jobs I had a knickname, Clark Kent. Mild mannered design engineer in the company and serious martial artist and race car driver (among other things) outside. You impress me as another one. - Jim (follow-up letter)

How do I get started? Click Here

Tom Gohring's School of Tai Chi and Chinese Kung Fu
6611 Airport Blvd., Austin, TX 78752 • 512-422-4245 • www.taichitom.com