In my previous article about flexibility, I detailed the fascinating tissue that’s known as fascia. In this second part of our series on flexibility, we will explore the various causes for what we perceive as “tightness”. In future articles, we’ll go into more depth about possible remedies for inflexibility. What can we actually do about tightness? For now, let’s discuss what makes us feel stiff, tight, and inflexible.

What do we mean by “flexibility”? 

There are numerous factors that affect our flexibility. When we use that term, “flexibility”, for the most part we are referring to how much can we move any particular joint through its full range of motion (ROM). Take your elbow for instance, which is a fairly simple hinge. It’s easy to envision full ROM. When you extend your elbow to it’s full ROM, your arm should be relatively straight. At full flexion, you bend your arm so that your hand should easily touch the shoulder or chest. If you have suffered an injury to the elbow or the surrounding area you may have limited ROM. Likewise, we have all known folks who have hypermobile elbows who can hyperextend the joint, making the elbow look like it’s bent backwards. I don’t know about you, but I’ve always felt that was disturbing to see people do that! Anyway, ROM is something that is easily identifiable and we can easily measure.

There are countless factors that can impact a joint’s ROM. But, what I wanted to focus on in this article is that all too familiar sensation of “tightness” or stiffness.

“Tightness” is an unpleasant sensation that feels abnormal…

A host of contributing factors can cause this sensation of tightness. For now, however, let’s agree that, whatever the cause, this sense of tightness translates as a physical feeling that something is wrong or feels not-quite-right when we move. It is a generally unpleasant sensation. It can even be painful when we reach the limit of our restricted range of motion. Our brain interprets these sensations as an abnormal state, as if we should be experiencing something different, something less unpleasant. Because of this, we generally think of flexibility in terms of more-is-better and the absence of it as something bad. This sensation is entirely subjective. Only you can know how your muscles and joints feel. We can’t objectively measure that sensation in the way we can measure ROM with a protractor.

If we accept that this sensation of tightness is not our body’s natural state and that when we feel it there is something not-quite-right, then we can logically conclude that our body’s each have a more optimal state of flexibility.

Optimal performance state

I believe most of us have had the good fortune to enjoy this feeling. For me, it feels fluid and free. There is an absence of pain or even minor discomfort. I feel balanced, strong and physically capable, agile, perhaps even graceful. I know that when my body is in this optimal physical state of being, my mind and spirit occupy a similar pleasant, powerful, and productive state. Physically, I feel like I can rip trees out of the ground, run for hours, and possibly even dance (not a pretty picture if you’ve ever had the misfortune to witness it; I’ve got all the rhythm of a fire hydrant…). I sleep much better and tend to eat healthier, with a deeper well of self-discipline. I feel rested and able to relax more. Mentally, my thinking seems clearer. I’m able to concentrate and focus. My memory is sharp. I also feel more of a sense of equanimity, that life’s problems are not so overwhelming and that I’m adequately equipped to deal with whatever comes my way. This optimal state is really quite invigorating. It is also elusive and unfortunately, transient. All too often life’s pressures and challenges disrupt the optimal state. It could be an exercise injury, or a bad night’s sleep, or a setback at work. Whatever the trigger, the disruption often causes a return of that physical sensation of cramped, knotted muscles and the accompanying tightness we’ve been discussing. It seems apparent to me that there is a direct correlation between my physical perception of “tightness” and my mental frame of mind.

So, what I’d like to explore in this piece are the causes of that unpleasant, and seemingly unnatural sensation we characterize as tightness. Perhaps if we are able to better understand what causes it, we can better address those causalities and do the work that will lead us to the much more desirable but elusive optimal physical and mental state described above.

Injury and illness are a couple of the more obvious transient sources of tightness. Just think about anytime that you’ve had a serious bruise or strain. The area around the injury is almost always stiff. It’s painful to move that limb or area of our body. And, our ROM is usually limited while the injury is healing. Our Physical Therapy team routinely works with these patients. In fact, they focus on flexibility and increasing ROM with nearly every patient that we treat. Now, think about a time you were recovering from the flu or some other sort of illness or infection. We often experience a more generalized stiffness for several days during and after the illness.

Inflammation and Inflammaging

The tightness that accompanies these episodes is a function of inflammation. Inflammation can run the gamut from localized to systemic, and low-grade to severe. Inflammation is our body’s natural attempt to begin healing itself. It is an immune response when it detects that something is wrong, such as an injury, or a foreign body or pathogen present. Initially, inflammation is necessary and natural as our immune system gets to work to begin the healing process. But, chronic inflammation is a sign that something more insidious is at work. It is usually a warning sign of some sort of underlying health issue. Because inflammation is such a complex and fascinating subject, we don’t have space to get into it in more depth here. But here is a link to a really informative website where you can learn more about it if you’re interested.

It likely comes as no surprise to those of us in our middle years or older, that inflammation is more common as we age. In fact, there’s a term for this: inflammaging.

“Human aging is characterized by a chronic, low-grade inflammation, and this phenomenon has been termed as ‘inflammaging.’ Inflammaging is a highly significant risk factor for both morbidity and mortality in the elderly people, as most if not all age-related diseases share an inflammatory pathogenesis. Nevertheless, the precise etiology of inflammaging and its potential causal role in contributing to adverse health outcomes remain largely unknown.”

It’s probable that chronic, systemic inflammation or inflammaging will contribute to the sensation of tightness. If we accept this conclusion, then it’s safe to assert that simply getting older can make us feel more tightness or stiffness. Obviously, this is a generalized conclusion, and is not borne out in every person’s experience. Some will experience more tightness as they age than others.

Another transient cause of tightness can be Delayed Onset Muscle Soreness (DOMS). This is the pain or discomfort that can result from exercise. “DOMS begins fairly soon after exercise and typically peaks between 24 and 72 hours thereafter. It generally dissipates within 6-7 days depending on mode, intensity and duration of exercise, as well as the performer’s fitness status. While the delayed soreness can range from mild to debilitating pain, DOMS also produces immediate weakness in the affected muscle, which generally lasts as long as the pain. DOMS can also produce swelling, tense muscles, reduced coordination and a limited range of motion.” Our friend Dr. Phillips recently published this informative article about DOMS and methods to ameliorate the discomfort it causes.

We know that many chronic conditions have symptoms of tightness. Parkinson’s Disease, Multiple Sclerosis, and rheumatoid arthritis, are just a few we can name. There are dozens. Each can contribute to inflexibility and a sensation of tightness to varying degrees.

OK, all of these possible causes of inflexibility make sense. But, what if none of them apply to us, but we still feel tight? What then could be cause?

Well, there are a handful of possible contributors…


We spoke briefly in Part 1 of this series about dehydration. Dehydration robs our soft tissues of their normal suppleness. We used the analogy of beef jerky, which is essentially desiccated muscle and fascia. OK, perhaps that analogy is a bit extreme; it’s very unlikely that anybody still living would ever have tissue that dehydrated. But it helps to illustrate our point. Dehydration is more prevalent in aging adults. Either because of medications or habits, many older folks don’t drink enough water or other conducive fluids to stay adequately hydrated. Environment and activity also effect our hydration. If you live in an arid climate or are very active you are more susceptible to dehydration. Happily, the remedy is really simple. Drink more, early and often.

Muscle extensibility

The length of our muscles can directly affect our flexibility and sensation of tightness. By their nature, muscles are meant to change their length in response to stimuli and loads. We can easily conceptualize this by thinking again of our elbow joint. When in full extension, the elbow elongates the bicep muscle. In full flexion, the bicep shortens. So, the bicep, like any muscle, will shorten and lengthen in response to whatever stimuli it receives. This ability to lengthen to predetermined limits is called muscle extensibility. It is thought that each person and each individual muscle has an optimal extensibility. A muscle is in its optimal state when it is freely able to lengthen sufficiently to allow full ROM of its specific joint. Each joint also has an optimal state of mobility. It can become hypermobile, meaning it has too much ROM. It can also become hypomobile when it has too little. If the muscles that affect a particular joint have shortened beyond this optimal range, the result is tightness.

Muscles are both plastic and elastic

An interesting aspect of our muscles and fascia is that they are both elastic and plastic. They are elastic in that they will stretch as loads act upon them, returning to their original shape and length once the load is removed. They also demonstrate plastic properties in that if sufficient force is applied over an adequate period of time, they can permanently elongate. Naturally, if too much force is applied the muscle and fascia can tear or rupture. But, short of the point of catastrophic injury, it is possible to increase the extensibility of our muscles more permanently. This property is known as plasticity.

OK, as our muscles and fascia are capable of plastically elongating they are also capable of more permanently shortening. What causes muscles to shorten?

The main culprits are disuse, and asymmetries or imbalances.

Disuse, or underuse, could well be the leading cause. We’ve all heard the phrase, “use it or lose it.” Our bodies adapt to what we do, or don’t do. Far too few are as active as we ought to be or would like to be, particularly as we move into our middle age and beyond. Often, disuse is also associated with chronic flexion of a particular joint. The muscles that articulate that joint can then become shortened. Our hip flexors and hamstrings are useful examples. Because our modern society spends so much of our lives seated, our hips and knees are chronically in flexion, which means they are often bent. When we sit, we hinge at the hip with our upper legs flexing toward our torso. Also in a seated position, our knees are bent such that our feet are on the floor while we are in a chair. So, long periods of sitting can lead to the shortening of our hip flexors and hamstrings.


Asymmetries, also known as postural imbalances, can also lead to muscle shortening. These are really pervasive. Very few people are free of at least some degree of imbalance. Our standing and seated postures are major contributors. Most people tend to shift their weight to one side or another when they sit or stand. Doing so over long periods of time, day after day, leads to chronic postural asymmetries. On the side that we tend to lean toward, we create muscle and fascial shortening. Conversely, on the opposite side, we create lengthening. Both, can contribute to the sensation of tightness we experience. For those who sit on their wallet, even if it’s a thin one, just that slight rise of the hip, can over time lead to significant asymmetries in our pelvis and spine, and the muscles and fascia that support them.

The effects that these imbalances have on our muscle shortening or lengthening are similar for our fascia. Because the fascial net is a continuous weblike network, what happens to one side impacts the other proportionally. Dr. Tom Myers, a thought leader on the fascial network and flexibility states…

“Therefore, how much and how long negative change has occurred in our connective tissue – from poor posture, too little movement, overtraining, injuries, and so on – will determine how many compensations are reflected in our fascia… After years of negative changes, the fascia will twist, compress, and tighten in some areas while becoming overly lengthened and tense in other areas, negatively affecting the anatomy and physiology of our muscles as well as the rest of our body”

The body responds to these disruptions in our fascia by depositing collagen at both sites. It is attempting to reinforce the areas of the connective web that it believes are under duress. That deposited collagen does in fact reinforce the tissue, but at the expense of making the reinforced tissue less pliant and less supple. The result is tightness and a loss of flexibility.

So, this long list of the possible causes of our inflexibility, lack of ROM, and the unpleasant feeling of tightness could lead one to think the pursuit of optimal flexibility to be fruitless. How are we ever going to surmount all these challenges that are seemingly conspiring to keep us stiff and tight? Thankfully, we know from scientific evidence and anecdotal experience what solutions are available to us. We are not consigned to an unhappy state of permanent tightness. In fact, that desirable optimal state of flexibility is within reach for most of us. All it really requires is some focus and a rather modest amount of time. We know devoting some of our time to myofascial release and various restorative stretching techniques can measurably improve our ROM, flexibility, and eliminate much of the sensation of tightness.

My own experience…

For me personally, a renewed focus on my flexibility required something of a mind shift. I needed to value flexibility as much as I did strength, power, speed, and aerobic capacity. It was important for me that I no longer perceived my flexibility as simply something I might get to when I’ve got more time, maybe when I’m done with lifting and running, as if it’s not really part of my real training but something of lesser value and importance. Once I changed my perspective to view my flexibility as an equal partner to my strength, power, and endurance, I was able to realize the truly wonderful benefits it contributes. And, now, that elusive but wonderful optimal performance state that I described earlier has become more of a norm than an exception. Flexibility can truly become transformational.

What can we do to improve our flexibility?

In Part 3 of this series we’ll begin to explore what we can do to relieve our tightness and increase our flexibility. To be


Acknowledgements: I am exceedingly grateful to my good friend Dr. Wayne Phillips for his expert guidance, professional insight, and collegial review of this article. As a practicing professor of Exercise Science, Dr. Phillips continues to educates students on this very topic of flexibility. His contribution to this series of essays has been invaluable.

Works cited:
1. Franceschi C, Campisi J. (2014). Chronic inflammation (inflammaging) and its potential contribution to age-associated diseases. J Gerontol A Biol Sci Med Sci. 2014 Jun;69 Suppl 1:S4–9. PubMed #24833586.
2. Frederick, Ann & Christopher. Stretch To Win, Flexibility for Improved Speed, Power, and Agility. Champaign, IL:Human Kinetics, 2006. Print.
3. Holzman Weppler, C., Magusson, S P. (2010). Increasing Muscle Extensibility: A Matter of Increasing Length or Modifying Sensation. PHYS THER, 90: 438-449.
4. Myers, Tom. Anatomy Trains, Myofascial Meridians for Manual and Movement Therapists. London: Churchill Livingston, 2014 Third Edition. Print.
5. Myers, Tom. “Fascia In Movement, the Essentials Preview”. Online video clip. Youtube, 30 April 2015. Web. 20 December 2016.
6. Nordqvist, C. “Inflammation: Causes, Symptoms, and Treatment”. Medical News Today. Healthline Media. 16 September 2015. Web. 21 December 2016.
7. Page, P. (2012). Current Concepts In Muscle Stretching For Exercise and Rehabilitation. The International Journal of Sports Physical Therapy, 7 (1): 109-119.
8. Phillips, W. “5 Tips to Tackling Muscle Soreness”. Stack. 13 December 2016. Web. 20 December 2016.

Paul Reilly

Paul is the Owner and Founder of MidStrong. He created MidStrong in 2017 to train men and women in midlife who are busy with work and family to build muscle and burn fat so they can look and feel better than they did in their 20’s. MidStrong is making Functional Fitness training safe and fun, and inclusive. He and his wife, Julie also own and operate MidStrong locally, their bricks and mortar business, previously called ACCELERATED Strength & Balance. It is a boutique fitness center specializing in training folks in and around Westborough through the challenges of midlife for more than five years.