We have all probably experienced what is commonly called a muscle knot. Of course, a muscle cannot tie itself into a knot, so what can explain this sensation? We often seek massage for these knots, and applying pressure on them seems to provide relief. Read on to find out more about this fascinating topic in an excerpt from The Physiology of Yoga.
A muscle knot is sometimes called a trigger point. In Myofascial Pain and Dysfunction: The Trigger Point Manual (1983), Janet Travell and David Simons define a trigger point as an irritable nodule, often palpable, in the taut bands of fascia surrounding skeletal muscles. They note that direct compression and muscular contraction on the point can incite a startled response (jump sign), local tenderness, local twitch response, and referred pain somewhere distant to the trigger point. As the title of their book suggests, they attribute these trigger points to microcramps in the muscle and issues with the fascia, at least in part.
Muscle knots
The book achieved great commercial success, but it relied on many assertions and beliefs that were derived without testing or without adequate scientific basis. In 1992, Wolfe and colleagues performed a study on trigger points. They recruited a group of four myofascial pain experts, selected by Simons himself and including Simons, who examined four patients with myofascial pain. The examiners could take as much time as they needed to examine but were not allowed to interview the patients. The four patients were controlled against healthy subjects as well as subjects diagnosed with fibromyalgia without the examiners knowing who was who.
Even though these trigger point experts were the best—Simons cowrote the book on it—they could not find or agree on the trigger points. The lead author of the study, Dr. Fred Wolfe, later revealed in a blog post:
“It was a disaster. The examiners were distraught. After the results were in, they protested and wanted to change the protocol and purposes of the study (post hoc). It wasn’t fair, they said . . . If we believed in trigger points and The Trigger Point Manual before, we were a lot less secure in our beliefs now.” (Wolfe 2013)
Muscle tension
Despite the lack of scientific basis behind it, the myofascial pain theory still dominates, even among professional circles, as an explanation of muscle knots.
Other scientists have tried to explain the phenomenon of muscle knots. Quintner and Cohen (1994) suggested that irritated or injured peripheral nerve trunks, rather than microdamage in muscle tissue, may be the cause of pain. Like the idea it is intended to replace, this hypothesis has advantages and problems; the main problem is that there is no obvious plausible mechanism for pervasive nerve irritation.
The reality is, to this day, we cannot clearly explain what a muscle knot is or the mechanism behind it. Yet few would argue the existence of muscle knots because we have probably all had one at some point. Whatever the mechanism behind these pesky irritants, here are a few methods worth trying for relief from them: resting, stretching, exercising, hot and cold therapy, self-massage or massage therapy, physical therapy.
References:
Quintner, J.L., and Cohen, M.L. 1994. “Referred Pain of Peripheral Nerve Origin: An Alternative to the ‘Myofascial Pain’ Construct.” Clinical Journal of Pain 10 (3): 243-251.
Travell, J.G., and Simons, D.G. 1983. Myofascial Pain and Dysfunction: The Trigger Point Manual. Baltimore: Williams & Willkins.
Wolfe, F. 2013. “Travell, Simons and Cargo Cult Science.” The Fibromyalgia Perplex (blog), February 19, 2013.