“I’ve got knots in my back,” is a common complaint. When students get to massage school they learn what knots are. Well, they think they learned what knots are. The truth is the explanation you heard was one of several theories. Don’t believe a theory just because you’ve heard it so often, “it must be true.” This post is going to explore the theories of metabolic accumulate, trigger points, myofascial adhesion, muscles sliding, and fibrous tissue.
One of the oldest explanations was that some minerals and metabolic waste got left behind and began accumulating. So you’ve developed a local deposit of minerals and stuff that needs to be broken down manually. Well the problem is the body is actually very efficient at removing metabolic waste. Even in sedentary individuals it doesn’t take that long. This explanation has fallen out of favor.
The explanation that most students probably still hear is that muscle knots are trigger points. The basic definition of a trigger point is an area that is tender when pressed on and it refers pain towards another part of the body. Trigger points are actually well mapped out and were considered scientifically accurate, but lately some therapists began looking back and discovered that this was more pseudoscience. The problem lies with when you ask why does a trigger point develop into a “knot?” The explanation is that it is a local twitch response. Not a spasm, because that would involve the whole muscle. The problem is that even if you’re looking at just a muscle fiber, the fiber does not contract in just one spot, a fiber contracts all or nothing. I’m not completely throwing away trigger points. I, as well as many therapists, got good mileage out of using their theories, but it doesn’t completely hold up to scrutiny.
As trigger points fall slowly from use the next most common explanation currently doled out is that knots are actually adhesions between two fascial layers. These fascial layers are connective tissues that run through and about all parts of the body creating order and support. If two parts that were supposed to slide past each other get stuck together then you’re going to experience limited range of motion, pain, and a knot. Fascia has been made popular by structural styles like rolfing and kinesis, and also gentler styles like myofascial release. I love how slow fascial work feels, but many therapists are questioning if fascia really has the properties it is attributed to have by the above styles. Turns out fascia probably can’t stretch out to the extent we thought and when you find out one thing is untrue the rest is questioned. The possibility that cross fibers can reach across adjacent layers seems plausible, especially in sedentary individuals or people immobilized by an accident/trauma. I imagine this will stay popular for a bit more.
A theory that is getting attention, and may be the next popular one is that a knot is just muscles that overlap. As you put pressure or manipulate the knot the superficial muscle will slide over the the deeper muscle and you’ll feel a bump slide back and forth under your pressure. This is probably true for some of the knots you feel. This explains the knot commonly found by the inferior trapezius as it slides above erector spinae muscles.
Another explanation that makes sense is that a knot is just fibrotic tissue. It could be especially fibrous muscle or tendon that has extra connective tissue. This may be due to some sort of stress like poor posture or a repetitively stressful activity. An example is how common it is to find a fibrotic levator scapula attachment at the superior angle of the scapula. This could be due to the common head-forward-posture and sedentary lifestyle.
So what’s a knot? I’m going to guess one of the bottom theories, but only because I want to be ahead of popular and accepted theory. If you want the most company you’ll want to stick with trigger points.