I caught a glimpse of this in the NYT, and thought it might be helpful to discuss in context:

Many experts believe that the knots, often referred to as myofascial trigger points, are “specific areas of contraction within the muscle fiber,” said Rob Grieve, a senior lecturer in physiotherapy at the University of the West of England in Bristol, England, who has studied the phenomenon.

The knots seem to develop when a muscle tenses repeatedly and “are normally not caused by a specific, traumatic event,” he said, “but by muscle overuse or faulty biomechanics.” (This is also known as slouching.) [source]

I’m not sure that “slouching” is the same as “biomechanics” – “slouching” is what you do when you could otherwise sit up; your “biomechanics” (how you and your different internal systems work) would only be affected if you, in a sense, developed a hump of sorts after years of slouching.

Either way, muscle fibers that are interrupted from doing what they are supposed to do – grow solidly, allow blood and nutrient flow, protect nerves – ultimately result in trigger points… ergo, muscle knots.

It is thought that these small bits of hyper-tensed muscle cause discomfort and pain by “blocking some of the normal blood flow to the affected tissue,” said Jan Dommerholt, a physical therapist in Bethesda, Md., who studies and treats muscle knots.

But writing in the March issue of Rheumatology, scientists from Australia and the United States pointed out that muscle knots rarely show up on scans, leaving researchers with “no scientific basis” for believing that knotted muscle fibers make us sore. Instead, the researchers contend, the soreness is likely neural, involving the brain and irritated nerve endings. [source]

I don’t think those two theories are at odds with one another – since nerve endings actually exist inside the muscles, it’s quite possible that a muscle, tensed up and restricting blood flow, would have some form of build-up that irritates nerve endings.

That being said, the lack of a mention of “lactic acid” leads me to believe that might not play the role many professionals think it plays.

This is a really interesting exploration of how muscle knots are viewed – muscle knots “rarely” show up on scans, therefore there’s no scientific basis for believing they contribute to pain? Do we understand why some muscle knots are visible and others aren’t? Are our scopes powerful enough or differentiating between different muscle fibers well enough for us to see?

I mean, even taking a look at the listing in the NIH database shows quite a presumptive listing. “We can’t see it, therefore it’s not real” is a weird stance to take in this instance, because the next question is… “are we looking with the right tools?” “Are our current tools powerful enough?”

So, I don’t know.

I like the theory of muscle knots are a combination of contraction of muscle fibers and an actual stopping of blood flow, because it explains why a good foam roll before annnnd after can so drastically impact the way one feels post-workout, and whether or not they actually experience muscle knots. Giving yourself the post-workout poor-man’s massage, or just a good after-training stretch gets the blood flowing and helps you heal properly. Increased blood flow to the tightened area not only transports oxygen to the area, but the necessary vitamins, minerals, and protein, too.

And, there’s advice on how to deal with them, as well:

Regardless of the possible cause, most therapists feel that the best treatment for purported muscle knots is to pummel them. Vigorously massage the sore spot with hands, Dr. Grieve said, or use a small, hard ball (such as those used for lacrosse) or a foam roller. [source]

I think it’s less about “pummeling” a spot, and more about unblocking the area where blood flow is inhibited. “Pummeling” – metaphorically speaking, I’m sure – could actually serve to make it worse. If you’re being pummeled in a way that only produces more muscle soreness, it could only cause more knots. (This is why most quality masseuses actually don’t pummel you – they know they could make it worse, ultimately making you find a new masseur instead of going back to them!)

Honestly, the comments on this one are really worth a look.

Getting the services of a good masseuse, or giving yourself a good session or two of foam rolling can be a gift. It not only helps you perform better, but helps you heal properly, without spending a third of the next day whimpering like a wounded animal. Take the time to learn a bit more about foam rolling, and invest in a good rolling device to help you get the job done. Trust me – trust me – your body will thank you for it!

Check out my comprehensive guide of foam rolling, and my infographic on foam rolling to help you get the job done!