Isometric / PNF: Agonist Contract

[Aahem]

"Agonist Contract: passively lengthen the tight muscle to it end-range. Then, have the patient concentrically contract the muscle opposite the tight muscle to acquire a new end range. The therapist applies mild resistance during the concentric contraction, making sure to allow for movement to occur. This technique incorporates reciprocal inhibition, which is controlled by a thin receptor in a muscle known as a muscle spindle. When one muscle contracts, the muscle spindle causes its antagonist to relax. Verbal ques for the patient performing this exercise would include, "push. Push. Push into my hand."

Hold-Relax with Agonist Contract: Same as Hold-Relax. Patient isometrically contracts the tight muscle against the therapist's resistance. After a 20 second hold has been achieved, the therapist removes his/her hand and the patient concentrically contracts the antagonist muscle (the muscle opposite the tight muscle, the non-tight muscle) in order to gain increased range of motion. At the end of this new range, the therapist applies a static stretch before repeating the process again."

That is a direct quote from wikipedia (http://en.wikipedia.org/wiki/Isometric_stretching).

Is this true? Would tightening the antagonist muscle (quads for a hamstring stretch) work for stretching? Better than passive stretching? This sounds like an easier method of isometrics to me. I thought contracting the antagonist (quads) also made the other muscle (hams) to contract in response instead of relaxing it? Or am I mistaken?

Any opinions or facts? Facts, preferrably?


- Ade

[Rahf]

I find it hard to contract the antagonist in a stretch. Without tensing the stretched muscle as well that is.

[Ashtar]

It is the complete opposite of isometric stretching. Isometric stretching describes when you contract the muscle you are stretching in a stretched position. Pinching the ground when training splits, for example, contracts your adductors, despite your attempting to stretch them. This is usually done off and on. I can't remember the explanation on why it's supposed to work, I think Tsatsouline writes it in his books or something.

The approach Kurz uses (which I think is different from Pavel) is it is done to strengthen that muscle, so that when you stretch in the future it, being stronger in a lengthened state, will be more willing to lengthen as it is not afraid of being unable to get out of that position. The personification of muscles is pretty cute.

Contracting the antagonist (the muscle that is short and not lengthened/stretched, as you are calling it) is a good tactic. It can be done in passive stretching, and help with it. It only becomes fully active (and non-passive) if the only force moving your limb is that antagonist (I think it might actually be more accurate to call this muscle the agonist and the one being stretched the antagonist, but whatever).

You can't do this very well in all passive stretches though. For example, you can't very easily perform a sustained or maximal contraction of your abductors in the splits, or you'd fall down and your adductors would tear. Your nervous system knows that. Same applies to front splits.

One the other hand, if you are stretching lying on your back, either flexing a leg at the hip using your arms, a strap, or a partner, you're more able to do this, especially prior to your leg passing the 90 degree (straight-up) angle where there is no load-bearing on the stretched muscle.

Even past that point, you are only bearing the weight of your leg, as opposed to bearing the weight of your whole body. It is less strenuous, so the stretched muscle doesn't need to be as strong, and it can lengthen more. This makes it safer to engage the muscle opposing the stretched muscle.

Ideally the safest way to do this would be with a standing stretch, but it's often harder to relax while standing up since one leg will be bearing weight, and you would need to keep your balance.

If you think about it, you DO engage your opposite muscles in a lot of stretches, with unnoticable microadjustments. When you perform a standing splits stretch yeah, you relax and gravity pulls you down... but it couldn't do that if you didn't at first widen your feet. You move your feet apart by abducting your hips along with microadjustments in hip rotation and ankle inversion/eversion back and forth.