Sensible advice for aches, pains & injuries

Why do Muscles feel Stiff and Tight?

Maybe your range of motion actually limited, or maybe it just feels that way

updated (first published 2007)
by Paul Ingraham, Vancouver, Canadabio
I am a science writer and a former Registered Massage Therapist with a decade of experience treating tough pain cases. I was the Assistant Editor of for several years. I’ve written hundreds of articles and several books, and I’m known for readable but heavily referenced analysis, with a touch of sass. I am a runner and ultimate player. • more about memore about

Feel stiff? Tight? Think your range of motion isn’t what it should be? These things often go together, but they don’t always, and they definitely aren’t the same. Wrapping your head around the difference is good human body owner’s manual stuff.

Only you can say that you’re stiff. “Stiff” and “tight” are imprecise, informal, subjective terms: they are noxious sensations that probably indicate minor pathology, a kind of mild pain. Stiffness is a symptom, in other words.

Range of motion (ROM)

How far can you go? Range of motion is the only obviously objective measure of flexibility we have to work with. You can measure ROM with a protractor.1 Limited ROM can be confirmed in joint that actually cannot move as far as it “should” be able to move.

Which is how far, exactly? Human averages are almost meaningless, because the range of natural variation is generally large.2 A better measurement might be how much you want or need a joint to move — for instance, gymnasts obviously need ROM more than accountants do. However, a desired or perceived need for ROM is not a good standard either, because so many people assume that their range is worse or more “abnormal” than it actually is, and because they assume that more range is better than it is. It’s not that great. Doing the splits is not especially useful.

Many people have significantly less natural ROM than many others, especially men in their hamstrings. This doesn’t really hold men back in any way other than being unable to touch their toes, and yet many men bemoan their lack of flexibility.

The martial arts seem to demand flexibility, and of course it can be powerful asset, but even there it’s not necessarily so. The most memorable martial artist I ever worked with — a formidable, grizzled old practitioner of Aikido — was also one of the least flexible.3

The sensation of stiffness

Stiffness is an unpleasant sensation. It feels like something is wrong. No ever feels comfortably stiff.

A short but healthy range of motion is probably not the cause of any wrong-feeling stiffness. If your ROM is limited by natural biological variation, pushing at the end of the range is a neutral sensation — it doesn’t feel like there’s a problem, and therefore it is not “stiff.” It’s more just a sensation of being stopped, or of pulling too hard. If there’s nothing actually wrong, they probably won’t really feel “tight” or “stiff” unless you are trying too hard to stretch them.

The feeling of wrongness leads to an understandable assumption that to feel stiff is to be stiff, equating stiffness with a limited ROM. But it’s not necessarily so. People with normal range, or even good range, can feel stiff and tight! And people with lousy range can actually feel perfectly fine.

Importantly, stiffness routinely occurs without coming anywhere close to the limits of ROM. You can feel stiff when you stand up from a chair: an easy action that isn’t even remotely constrained by your flexibility. What’s uncomfortable is movement, contraction, and tension on anatomical structures well within normal ROM.

Similarly, when you are store after a hard workout, you can stretch just as far as normal — it will just hurt more. Everything hurts more! All stimulation of your muscles is uncomfortable (stretch, pressure, vibration, anything). And yet people are just as likely to describe this state as stiff as sore or painful.

“I feel really stiff — it’s nice!”

said no one ever

What causes stiffness?

If stiffness is a symptom, what’s the disease? There are many possible causes of stiffness:

But not limited range of motion.

Trying to diagnose stiffness is just as difficult as trying to explain pain in general, and maybe even more difficult: stiffness is more subtle. It’s like trying to diagnose a “funny feeling.”

Obvious causes of stiffness: sickness and exercise soreness

There are a some familiar circumstances where we obviously get stiff: the early stages of cold or flu, and the soreness that follow relatively big bout of exercise (delayed onset muscle soreness). Infections clearly involve inflammation and immune system activity; it’s a lot less clear that what’s going on with exercise soreness, but it definitely involves some kind of tissue distress.4 Both states often cause actual pain as well. We can infer from this that stiffness must have something to do with mild tissue irritation.

But lots of people are stiff without an obvious cause like exercise soreness or infection. What else could be going on?

The stiffness of aging and arthritis

Why would we have tissue irritation without an obvious source ? Chronic mild to moderate tissue inflammation has many possible causes, and is probably more prevalent and persistent than most professionals realize.5 But by far the most familiar source of inflammation — and stiffness — is probably aging. Everyone gets more inflamed as they age. This is known as “inflammaging” — seriously — and it happens to some people sooner and worse than others,6 like arthritis (which may itself just be one of the effects of the inflammation).

But then there are also many young people who feel stiff. What could be going on with them? There’s still many possibilities, but muscle knots are one of the most likely.

Muscle knots (myofascial trigger points)

Some tissues probably create stronger sensations of stiffness when irritated, and a prime candidate here is muscle. But why would muscle get irritated, other than a big workout? For younger people who feel stiff (and can’t just blame “inflammaging”) there is one major suspect: the ubiquitous phenomenon of “muscle knots,” technically called trigger points. These patches of soft-tissue that are sensitive to touch for no apparent reason are extremely common, and the pain is the tip of a bio-berg: for every spot that actually hurts (and “active” trigger point), there’s usually more that are just mildly uncomfortable (“latent”). There’s a sort of diffuse halo of stiffness and tightness around trigger points.

It’s unknown whether trigger points involve literal muscular tightness. They may be, and the dominant theory is that they are basically micro cramps. On the other hand, the dominant theory is old and controversial,7 and trigger points could be pure neurology and sensation.8 So trigger-pointy tissues may actually resist stretch, or their extensibility may be unaffected,9 but they will feel stiff either way.

Psychological stiffness

Maybe if you feel limited emotionally you might feel that way in the flesh too. Some stiffness may be a form of self-expression.

This is somatization, and it’s not that far out. Psychosomatic illness is probably more common and more serious than we realize, and milder forms therefore are also likely ubiquitous.10 We already know that mood, posture and even pain sensitivity can modify each other1112 It’s really not much of a leap that believing you are stiff could result in feeling that way. Consider how a stressful situation can actually feel “suffocating.”

Body is not stiff, mind is stiff.

K. Pattabhi Jois

About Paul Ingraham

Headshot of Paul Ingraham, short hair, neat beard, suit jacket.

I am a science writer, former massage therapist, and I was the assistant editor at for several years. I have had my share of injuries and pain challenges as a runner and ultimate player. My wife and I live in downtown Vancouver, Canada. See my full bio and qualifications, or my blog, Writerly. You might run into me on Facebook or Twitter.

Related Reading

For more information about trigger points, see my ebook Trigger Points & Myofascial Pain Syndrome or free articles like my popular Perfect Spots series. For more about why stretching is over-rated, and why most people stretch for the wrong reasons, see Quite a Stretch: Stretching Hype Debunked — which is always good for starting an argument. And the two topics merge in Stretching for Trigger Points, which is an excerpt from an even more ridiculously detailed section of my book.

Some other related articles…

What’s new in this article?

JanuaryThorough editing, numerous clarifications, some pruning and re-organizing. The article now focusses much more strongly on causes of the symptom of stiffness.

2016Several miscellaneous improvements, especially new information about the role of inflammation and “inflammaging.”

2016Minor update. Added a neat footnote and citation about the trouble with “average” ranges of motion. Plus miscellaneous editing.



  1. Actually, a “goniometer” — a more advanced sort of protractor used for measuring limb angles in kinesiology (and much else). BACK TO TEXT
  2. Ironically, almost no one is average, if you take more than a couple measurements of them. For instance, the American Air Force had a crisis of excessive crashing in the 1950s because they’d built their cockpits for “average” pilots, but most pilots didn’t fit in one or two crucial ways, and couldn’t control their planes because of it: “When he looked at just three [measurements], less than five percent [of the pilots] were average. Daniels realized that by designing something for an average pilot, it was literally designed to fit nobody.” That’s from a fascinating article/podcast episode on this topic: see On Average (Episode 266 of 99% Invisible). BACK TO TEXT
  3. He seemed flexible, but it was all in how he used what little range of motion he had. He worked within his limitations like an artist, and you probably would never even guess that he had quite limited ROM unless you spent time with him in training, and watched him failing to touch his toes. BACK TO TEXT
  4. The traditional notion of “microtrauma” is probably wrong, or at least only half the story. The most promising modern theory is that the discomfort is caused by “neurological growing pains,” as nerves literally grow in response to exercise. For more about this, see Post-Exercise, Delayed-Onset Muscle Soreness. BACK TO TEXT
  5. PS Ingraham. Why Does Pain Hurt? How an evolutionary wrong turn led to a biological glitch that condemned the animal kingdom — you included — to much louder, longer pain. 5139 words. Research has shown that immune cells (neutrophils) unnecessarily “swarm” sterile injury sites, causing damage and pain with no known or likely benefit as a tradeoff. It’s just a clear error: they appear to have mistaken mitochondria for a foreign organism, a legacy of ancient evolutionary history, and a biological glitch with profound implications about why some painful problems are so severe and stubborn. BACK TO TEXT
  6. PS Ingraham. Chronic, Subtle, Systemic Inflammation: A possible insidious cause of mysterious chronic pain. 4509 words. Chronic, subtle, systemic inflammation is a possible factor in stubborn musculoskeletal pain. It can have many underlying causes, from bad genes to mild autoimmune disease (including allergies), smoking or other severe biological stresses, chronic infections, and even just getting old (known as “inflammaging”). The greatest culprit is metabolic syndrome: a set of biological dysfunctions strongly linked to poor fitness, obesity, aging, and likely emotional stress and sleep disturbance as well. BACK TO TEXT
  7. [Internet]. Wolfe F. Travell, Simons and Cargo Cult Science; 2013 Feb 19 [cited 17 Oct 27].

    An informal survey of the poor state of trigger point science from an articulate expert, Fred Wolfe, a rheumatologist. Dr. Wolfe gives his first-hand account of the first trigger point diagnosis reliability study in 1992 (see Wolfe), and he tells the story of meeting Dr. Janet Travell and observing her unscientific conduct with a patient.

  8. Quintner JL, Cohen ML. Referred pain of peripheral nerve origin: an alternative to the "myofascial pain" construct. Clin J Pain. 1994 Sep;10(3):243–51. PubMed #7833584. PainSci #54775.

    Quintner and Cohen’s 1994 paper is a historically significant critique of the “traditional” (Travell & Simons) explanation for the phenomenon of trigger points, known today as the “integrated hypothesis.” They propose that peripheral nerve pain is a better explanation. More specifically, they proposed that irritated or injured peripheral nerve trunks may be the cause of pain, rather than lesions in muscle tissue. This hypothesis has advantages and problems, just like the idea it is intended to replace. Its main problem is that there’s no obvious plausible mechanism for ubiquitous nerve irritation. I review the hypothesis more thoroughly in my book, Trigger Points & Myofascial Pain Syndrome.

    An updated version of this paper was published in 2015 in Rheumatology (Oxford).

  9. It depends on several variables, like the muscle mass and length and the number and severity of the trigger points. Also, the mechanism of stretch-resistance is unknown: it could be physical tissue stiffness (the nervous system is willing, but simply cannot overcome physical resistance in the tissue), or inhibition and resistance (the brain refuses to allow the stretch, because it’s too threatening). That’s a sloppy thumbnail sketch, just for glimpse at how complicated it all is. BACK TO TEXT
  10. O'Sullivan S. It's All in Your Head: True Stories of Imaginary Illness. Chatto & Windus; 2015. BACK TO TEXT
  11. Bohns V, Wiltermuth S. It hurts when I do this (or you do that): Posture and pain tolerance. Journal of Experimental Social Psychology. 2012 Jan;48(1):341–345. PainSci #54508.

    Here’s an easy science-powered pain relief tip: Stand tall! Assume a bold, confident posture. Or, as a mentor of mine liked to put it, “Tits up!” This research showed that “power poses” actually reduce pain sensitivity. It was inspired by other research (Carney et al) showing that “power poses” make people feel and act more powerfully, complete with hormonal changes.

  12. Carney DR, Cuddy AJ, Yap AJ. Power posing: brief nonverbal displays affect neuroendocrine levels and risk tolerance. Psychol Sci. 2010 Oct;21(10):1363–8. PubMed #20855902.

    This experiment supposedly shows that adopting a “powerful” (confident) pose changes people’s hormonal levels and increases their willingness to take risks as if they actually had more power. “A person can, by assuming two simple 1-min poses, embody power and instantly become more powerful.” This is plausible and interesting, but melodramatically stated, and probably over-stated. There’s a very popular TED talk about this paper, and so (unsurprisingly) the authors have been accused of reaching beyond what their data can support:

    So, take this idea with a grain of salt.

    See also Bohns, which presents evidence that power postures can also reduce pain sensitivity.