Muscle imbalances and muscle dysfunction: Identifying these key causes of chronic pain and movement impairment

[Word Count: 8000 | Estimated reading time: 30 minutes]

You probably came here because something in your body doesn't feel right. You probably have chronic pain in one or multiple joints.

You came across this "muscle imbalance" term and are pretty sure it applies to your achy-breaky body.

I've been in the same situation. I suffered for years with chronic pain in my back, hands, wrists, shoulders, hips, knees, and feet. Conventional medical advice and physical therapy were a dead end for me. Acupuncture, chiropractic, and massage all failed to give me lasting results.

What gave me freedom and confidence was learning how to move my body right. As I started to move right, I started to feel right. 

Let's start with the basics. Muscles are the organ of physical integrity and movement. Without your muscles, you would be a sack of bones and blood stuck on the floor. So if you want to move right and feel right, you need to understand muscles. 

In this article, we’re going to define muscle imbalances, dysfunctional muscles, and talk about how to identify them.

After you bone up on muscle imbalances in this article, you'll want to read the follow-up article for specific strategies to fix muscle dysfunctional muscles and muscle imbalances (coming soon)


What are muscle imbalances?

Muscle imbalances come in two general flavors. In both cases, you’re comparing the achievable length and strength of the muscles in question. 

Joint muscle imbalance

The first category is an imbalance around a joint. We'll call it a joint muscle imbalance. This is when we are looking at muscles that cross over a specific joint (or joints). 

Joint muscle imbalances are a problem of how muscles work together to produce a movement or maintain a position. This is when muscles with different roles in a given movement do not exert forces in a manner that allows for full and pain-free motion.

Put another way: joint muscle imbalances are when muscles on one side aren't as strong or as extensible (able to get longer) as they need to be to accommodate what's happening on the other side.

Here are a few examples of joint muscle imbalances.

Compare the length and strength of the hamstrings versus the quads and the effect on the knee joint.  

quads vs. hamstrings muscle balance


You could examine the strength of the inner thighs to create adduction versus the strength of the outer hip to create abduction. 

abductor vs adductor muscle balance


Many people have very weak inner thighs. If they’ve been doing Instagram influencer booty workouts, they may have strong outer thighs and hips. While this may be en vogue, it does not create a functional, balanced body. Having weak, atrophied inner thighs will make life a lot more challenging in the long run. 

weak inner thighs example

Original photo By CHRISTOPHER MACSURAK from Chicago, USA - CC BY 2.0


A joint muscle imbalance can involve multiple joints. For a multi-joint/multi-muscle example, you could look at the length and strength of the anterior abdominal musculature (your abs!) versus the strength of the lumbar and thoracic spine extensors (the muscles along your spine).  

You might also consider whether the spinal extensors can get long enough to allow for a flatter spine and better pelvis position. 

anterior posterior core muscle balance

Abs not strong enough to counter spinal extensors? Or spinal extensors not able to lengthen?

Length and strength are both crucial considerations. Sometimes you may have a problem with muscles being stuck short. Sometimes you may have a problem with muscles being too weak in a given length or position. Most of the time, it's a combination.

Another classic example of a joint muscle imbalance is comparing someone’s hip flexors to their butt muscles.

Matt may have extremely strong hip flexors that are great at creating hip flexion. But his hip flexors may be very poor at lengthening. Also, his glutes may be weak and unable to generate hip extension. This would be considered a muscle imbalance. The muscles that perform one motion are far stronger than the muscles that create the opposite motion.

example of hip flexion

Good hip flexion


example of poor hip extension

Poor hip extension


How do we identify joint muscle balance problems? We'll get to the process of identifying muscle imbalances in a moment. First, let's look at the next type of muscle imbalance.

Symmetry Muscle Imbalance

The second category of muscle imbalance is a symmetry imbalance. This is when we compare the same muscles on the left and right side of the body.

A classic example would be to compare the quadriceps muscle group on your right leg to your left leg. Many people have a glaring asymmetry in their thighs. One side is clearly thicker than the other and/or one side is clearly stiffer than the other.

Most people find this stretch much harder for one leg than the other.

Another symmetry muscle imbalance example: You notice that the muscles on the right side of your neck and shoulder are of a different shape, size, and strength from the muscles of the left side.

In this video, you see the right side of his neck muscles do not contract as much and are much flabbier than the left side. 


These would all be clear symmetry imbalances. 

Now that you know what joint muscle imbalances and symmetry muscle imbalances are, let's talk about why they matter.

Why do muscle imbalances matter?

Muscles are the organ of movement. Bones go along for the ride. Muscles determine the resting position, range of motion, and path of motion for your bones. If you want your spine to assume a certain orientation, you do it with muscles. If you want to grab something overhead, you do it with muscles. If you want to stand up from a chair or go for a run, you do it with muscles.

Never forget: muscles move the bones.

Unless bones are shattered or formed in a way that is a large deviation from normal (like scoliosis), bone shapes have a very limited influence on the available range of motions.

Even orthopedic “pathologies” like arthritis, joints that are allegedly misshapen by a few millimeters, and alleged damage to soft structures in the joint have been shown to be irrelevant to ranges of motion and pain. (Read more on pain here or this book by an orthopedic surgeon [affiliate link]).

When muscles are imbalanced, the interplay between groups of muscles is out of whack. When muscles get too far out of whack, it negatively affects resting position, range of motion, and path of motion. This makes it difficult to perform athletic endeavors and activities of daily life. 

When you have a joint muscle imbalance, you may feel jamming and pinching sensations near a joint. You may feel aching near a joint. You will notice certain ranges of motion become completely inaccessible no matter how hard you will your body to do them. Your repertoire of movements becomes constrained. Left alone, these constraints fester and limit you further.

When you have a symmetry muscle imbalance, your body is set up for serious frustration. It can lead to joint muscle imbalances and muscle dysfunction all over the place. 

If you’ve ever twisted an ankle, you’ve seen first-hand how a symmetry imbalance can wreak havoc on your body. If you have a bum ankle, your left and right ankle muscles are functioning in very different ways. Your muscles on the injured side are not functioning the same as on your healthy side. This creates a chain reaction in your knees, hips, spine, shoulders, and neck. It’s called a limp. If you end up on crutches, your entire method of locomotion changes dramatically.



If you are lucky, your ankle’s functional abilities return to normal and you nix any remaining trace of the limp. If you’re the average Joe or Jane, though, you have no idea what your ankle’s FULL functional abilities are, and you end up with issues.

In the future, you make do with whatever your bum ankle can do. Your doctor or physical therapist says, “meh, that’s just how it is as you get older.” You may have a small or large trace of the limp. Over time, you notice extra soreness in your low back. And after another five to ten months (or years), you end up with a bum shoulder or a crick that only happens on one side of your neck...

The end result of symmetry imbalances is body-wide adaptation. If you leave a muscle imbalance to fester, it can turn into many more issues all around your body. So we want to identify and address symmetry muscle imbalances before they become larger sets of multiple problems. 

Doctors, physiotherapists, chiropractors, and trainers may claim that symmetry doesn't matter. I have seen intelligent writers that I respect make this claim. 

To be fair, there are no prospective double-blind placebo-controlled studies available; no huge studies show that [degree of asymmetry x] correlates to an experience of pain or discomfort. No studies show that "if your left quadriceps group is 40% weaker than your right at creating knee extension, you'll experience back pain." No studies show that "if your thoracic spine has curvature of [x degrees], you'll have shoulder pain." 

That doesn't mean that muscle activity and body position are irrelevant. But we should recognize a simple limitation of the research.

Attempts to show correlation between muscle imbalances and specific symptoms will forever fail. Why? Because individual variations will confound the results. Pain tolerance varies by individual. Proprioception varies by individual. Ideal muscle resting length varies by individual. Ideal muscle strength (of the muscles in question and the ones surrounding it) varies by individual. Compensation patterns vary by individual. 

All these things that vary by individual also vary by context. For example, your pain tolerance is affected by your mood, your relationships, your job, your stress levels, etc. The strength of your left quads are guaranteed to be different from mine - which is guaranteed to be different from my friend's. The way you get in and out of a car is different from how a gymnast might get in and out of a car. Your CAR is probably a different height than mine. How long you spend in a car is different from how long I spend in a car. Two runners will have different strides. Two bikers will have different limb and seat geometries. The list of potential confounding factors is endless. 

It is impossible to quantify and adjust for all these confounding factors. At best, researchers can try to ignore them and claim that a large enough sample population would negate their effects. That might work for a drug trial, but it makes no sense to ignore the condition of an individual body's movement system when you're studying the body's movement system. 

It's like saying you can research the effect of watering gardens every day - while ignoring the types of plants in the gardens, the condition of the soil, the amount of direct sun the gardens get, and the overall climate the various gardens are in. You'd have a bunch of flawed data that would lead you to conclusions that would kill a lot of plants. 


Ultimately, the question of symmetry muscle imbalances is one of physics. Our bodies have mass. If I position or move my mass symmetrically, it requires muscles all over my body to work in a specific way. If I position or move my mass asymmetrically, it requires muscles all over my body to work in a specific and different way. 

We know that muscles can signal fatigue when worked to exhaustion. We know that muscles can signal stiffness or "tightness." Asymmetrical work will cause some muscles to signal sooner than others. This is all normal muscle function. 

If I walked around with a phone held to my head with my left hand, you would expect my arm and shoulder muscles to develop aches and pains within a few hours at most. My right side? Not so much. It's just hanging out. 

But if I maintained that pattern for years, is it plausible that the strength of the left side of my neck might deteriorate? That the right side of my neck and my right shoulder might show some effects from having to do all the work my left doesn't as I go about my day? 

The answer is yes. 

I'm not against science at all. I am against scientism that blinds us to the obvious and absolves us of responsibility for our own actions. We don't need to double-blind placebo control tests to verify that if I let go of an iPhone, it will fall to the floor. These are simple observations of cause and effect in our physical real world. 

The consequences of muscle imbalances are varied. They carry different probabilities in different contexts for different people. We can't always predict the consequences of specific muscle imbalances. But we can say that there are physical consequences to physical choices.

The more pronounced the asymmetry and the longer it's allowed to fester, the higher the probability of problems. The problems are not guaranteed, but they are likely. Those problems could be with pain, strength, and/or range of motion.



A note for skeptics in pain

If you have chronic joint and muscle pain and you're skeptical it could be related to muscle imbalance, I have simple advice (this is also assuming you've ruled out the extremely low probability causes like cancer).

Pretend that muscle imbalances are causing your issues. Train your muscles to correct the obvious asymmetries despite your skepticism. If you fix your asymmetries and dysfunctions and you still have pain and discomfort, then what have you lost? Did the gamble cost you anything?

You haven't wasted time. You've made your body stronger, and you will have learned something new about your body. 

In the vast majority of cases, you will also have learned that muscle imbalances were causing your issues. 


In summary, having joint muscle imbalances limits your ability to perform basic movements. Being too asymmetrical and too imbalanced limits your capacity to do all kinds of movement and physical work. Internally you feel your limited capacity. You feel afraid to bend over to pick up grocery bags. You feel reluctant to lift your child. You feel older than your years…

getting old meme

When pushed too far and/or too long, imbalances result in acute and chronic pain. They make something as simple as sleeping feel problematic. 

Finding muscle imbalances helps you identify muscles that are not performing to their optimal levels. That helps you become someone who can move right and feel right.


How to identify muscle imbalances  

When looking at a human body, you can spot clear signs of imbalance/asymmetry. There are two steps of assessment. Neither is high tech. Neither requires special training or devices that cost thousands of dollars.

These steps require nothing more than your eyes and your brain. In short, muscle balance assessment is cheap and easy.

Step 1 to find muscle imbalances: visual assessment

Your first step is a visual assessment. A visual assessment gives you quick and dirty information.

You can easily see when someone has no butt muscles (or flat, sagging, deflated butt muscles). Muscles without volume are muscles that don't get used. 

flat butt weak glutes example


You can see people with their shoulders stuck in a forward slump. This tells you about muscle function. Muscles on the front of the chest are in a generally shortened state and the muscles in the back near the shoulder blades are in a lengthened and (likely) weak state.

weak back muscles leads to hunchback posture

Looking at the spinal erectors, you might see one side sticking out and the other invisible. That would be a clear sign that one side activates more often than the other.

Torso Rotation Assessment for the Back Pain Fix


Looking at neck muscles, you might spot one side that’s more developed than the other.

man with asymmetrical neck muscles

Visual assessment gives you good clues right away.


Step 2 to find muscle imbalances: functional assessment

To get detailed information that verifies a muscle imbalance, we use functional tests. 

This is a fancy way of saying “try exercises or movements.” As you encounter difficult movements, you learn about the state of muscles throughout the body.

For example, you can’t do a row without fatiguing out after 8 reps but you can do fifty pushups? 

Sounds like your pushing muscles are in a lot better shape than your pulling ones.


You can lift your right leg up in front of you, but you can’t do a single leg bridge on that leg to save your life? Pretty glaring imbalance. 

You can’t tilt your head to the right but you can to the left? That would be a sign of a symmetry muscle imbalance.

More often than not, you'll find that the motions you can't do are accompanied by pain or discomfort. You'll experience jamming, pinching, or aching sensations. You may experience fatigue quickly. These are clear signs something is imbalanced. 

The key is to find the obvious, low-hanging fruit and start addressing it. There’s no need to obsess over tiny degrees of difference. The modern human's lifestyle leads to profound muscle imbalances. That means it won't take you long to find an imbalance. When you find one, start working on it.

It’s important to remember, though, that this is not where the journey ends.

You see, muscle imbalances are the first layer in the long process of becoming a human who moves right and feels right.

Finding muscle imbalances is actually just skimming the surface of the deeper process of identifying dysfunctional muscles all over your body. 


Dysfunctional muscles are the real villains hiding in our bodies

To be clear, finding muscle imbalances is important, but it's not a complete picture. The search for muscle imbalances is the first layer in the search for dysfunctional muscles.

Let me give you an example.

Let’s say you do a quick comparison between the hip flexion strength and range of motion on your right side versus your left. Your right side comes up to about 60 degrees of flexion.

The left side comes up to only 50 degrees of hip flexion.

weak hip flexors

You also discover that you can keep your right leg up for 30 seconds at that height without issue. On the left, you can only stay at 50 degrees for 5 seconds before the thigh starts burning.

Now you know that your left SHOULD BE ABLE to do 60 degrees of hip flexion. The right side can do it just fine. 

You can start addressing that imbalance ASAP. But you should keep in mind that what you’ve really discovered is BOTH SIDES are dysfunctional.

Cue horror soundtrack.

luke skywalker meme on muscle function

In this example, your hip flexion range of motion is limited on BOTH sides. The left side is WORSE than the right side, but neither side is that good. Not only are your muscles imbalanced from side to side, but they’re also dysfunctional on both sides. Fixing the symmetry muscle balance won't be a complete fix. 

"Really? Dysfunctional? What so wrong with that range of motion? I would kill for that range of motion!" you might be saying.

The problem is that you can't lift the weight of your own leg through a pretty minimal range of motion. You couldn't lift your own knee to your own chest if your life depended on it.

And in some ways, your life does depend on it. What if you needed to step up onto a high rock or ledge to get over a big gap? What if you just wanted to step over your nephew's skateboard on the garage floor without breaking your neck (or the board)? Or if you needed to step over a large log to get away from a pack of hungry hyenas? 

Modern life presents few true in-the-moment life and death situations, so we can get away with dysfunctional muscles for a long time. But life is a lot better when your muscles function well. Your options increase and your ability to deal with challenging situations improves. This, in turn, leads to more confidence, less pain, and a better mood. 

Your body is a lot more comfortable when muscles get adequate challenge on a regular basis. Your body is a lot more comfortable when your muscles are capable of taking on new challenges! 

To be able to handle varied challenges, you need functional muscles. Varied challenges will also give you functional muscles! So, let's dive into dysfunctional muscles so we can make them functional. 

What is a dysfunctional muscle?

A dysfunctional muscle is one that: 

  • cannot lengthen or shorten enough to allow smooth joint mechanics 
  • does not have the strength to control the bones to which it attaches 

We define a muscle functioning to its “full potential” when it's able to produce adequate force to create pain-free movement into and away from its fully lengthened and fully shortened states as well as into and away from intermediate lengths along the way.  

Put more simply: it has strength at every length. 


How do we end up with dysfunctional muscles and muscle imbalances anyway? 

Let's take a moment to answer this question. People often have an idea of their bodies as perfectly self-regulating. There's certainly some element of truth to this. Our bodies are incredibly complex and do an excellent job of maintaining function throughout our lives, even when we're making bad choices.

That said, there are always limits to what your body can handle. You could probably get away with eating nothing but butter for a few months or years, but eventually your digestive and cardiovascular systems are going to want to have a chat. 

meme about eating butter

Our muscles are incredible at adapting to the demands placed on them. When our lives place varied demands on our muscles, our muscles respond to meet the challenge. As long as we don't massively exceed our muscles' abilities, our muscles gradually adapt. 

When we place repetitive and limited demands on our muscles, our muscles adapt.

If we never lengthen a muscle, it will no longer be able to lengthen without a lot of effort. If we never contract a muscle, it will be unable to contract with much force, if at all. 

When our lives put us in positions where some muscles are squished and choked off from any blood supply, those muscles atrophy (it is not surprising that people who sit all day often have no butt muscles). 

With many of us spending our waking hours sitting in chairs and participating in repetitive recreational activities, it's easy to see where dysfunction and imbalance arise. 

A golfer always swinging to the left trains his body into massive symmetry imbalances. A desk worker who slouches while typing all day will find it difficult to un-slouch. Her spinal extensors become dysfunctional. A long-haul truck driver will find it hard to stand up, walk, run, jump and move his arms and shoulders through a full range of confident motion. Muscles all over his body become dysfunctional from disuse and chronic, repetitive positioning. 

And, to be clear, someone standing with "perfect posture" all day long won't be better off. Being stiff and stuck in a "straight" position can be just as dysfunctional as being stuck in a slouch. If you can't flex your spine or touch your toes because you've been locked in "perfect posture" all day, you've still got problems. 

men standing in military posture

"Guys, can any of you touch your toes?"


The more you ask your muscles to specialize in specific motions or positions, the worse they get at handling the variety of basic movements necessary to feel confident in your body. 

How to identify a dysfunctional muscle.

The process for identifying a dysfunctional muscle (or muscle group) is the same as for muscle imbalances. We use low-tech tools that humans have always had easily at hand.

To identify a dysfunctional muscle, we use:
1. Visual assessment which must then be augmented with...
2. Functional tests (AKA an exercise that precisely recruits our target muscle in a specific orientation)

Let’s look at an example of how we could do this with someone’s hip flexors.

Step 1 to find a dysfunctional muscle: visual assessment

For visual assessment, we look at the person and notice that they are actually stuck in a bit of hip flexion. This presents as anterior pelvic tilt with extension of the spine. The thigh muscles are not very well developed. This visual assessment tells us that the muscles of the anterior hip are resting in a shortened state AND are likely to be weak/dysfunctional.

example of anterior tilt muscle imbalances

We might also notice that the thigh appears to be bony. There's no meat! There’s NO size to those muscles. Muscle strength is not always directly related to size, but if you notice that a muscle is so atrophied that it’s not there, you can safely conclude that the muscle isn’t strong. It's not getting used enough to maintain decent size.

So, in short,  we look at the muscle.

woman with weak thigh muscles 

Step 2 to identify dysfunctional muscles: Functional test

Again, functional tests are just another name for "do a movement or exercise."  

For the functional test, we ask the person to do something simple. Lift the leg straight up in front of you (sagittal plane for nerds), bending the knee. Can this person hold the position for 5 seconds? 10 seconds? 30 seconds?

Can-can / Standing hip flexion from Upright Health on Vimeo.

If the fatigue and cramping start in under 30 seconds (and it usually does), you’ve got yourself some weak hip flexors. Most people can’t do this for even 5 seconds without fatigue or cramping of muscles. Sometimes it's in muscles OTHER THAN the hip flexors. (This would tell you that the body is using muscles other than the hip flexors, and those muscles don’t like it.)

We can also ask the person to adopt a position that tests the hip flexors in a lengthened position.

Taking a long stance, we ask them to maintain a flat lower spine / posterior pelvic tilt throughout the entire motion. We ask them to bend the back knee to see how low they can go AND if they can use the hip flexors/quads to bring them back up to the start position.

Split squat tucked from the FAI Fix 


If they can barely lower themselves down or it causes them intense discomfort to even try, we know the muscles on the front of the thigh are dysfunctional. They are unable to lengthen. They are not strong at length. 

If they can get part of the way down, but it's intense (with the muscles screaming and fatiguing rapidly), we know that the muscles are dysfunctional. They are weak at length. 

If they can get all the way down and back up without issue, then the hip flexors and quads are doing well in that lengthened position. (*note: this basically never happens for the average deconditioned person). 

Another example of a dysfunctional muscle (group)

Modern humans who sit in their cars, on their couches, and in their office chairs often have chronically shortened and weak hamstrings.

In any given individual, we can see this by observing:

  1. Lack of size in the back of the thighs. If the thighs look like a thigh bone, the muscles of the thighs are missing. When an adult participates in an activity that has created well-developed hamstring muscles, the next observations are then crucial.
  2. An inability to bend at the hip joints and touch the floor. For the majority of adults, this results in the knees bending, the spine flexing, and/or sections of the hamstrings crying out in agony. Even with these compensations, many adults still cannot touch the floor comfortablyflexible man touching the floor
  3. An inability to lift moderately heavy objects off the floor (25% of your own body weight) while maintaining a straight spine and straight knees (and often also impossible with bent knees)
  4. An inability to bend the knee and pull the heel up toward the butt using the hamstrings (and no hands!) for 30 seconds without massive (and alarming) cramping

hamstring curl exercise

I hope you tried the tests above. 

If you did the tests above and failed, don’t feel bad. The overwhelming majority of modern white-collar workers will fail at least one (if not all). Blue-collar workers whose jobs actually put them into a variety of physical positions might do better, but even they are often grooved into very limited daily movement patterns.

Suffice it to say that dysfunctional hamstrings are very common. It’s tough to accurately estimate how prevalent dysfunctional hamstrings are. Based on my own observations as an adult male, I’d say 85% of all men between the ages of 18-99 have dysfunctional hamstrings. 

I don’t think it’s that much different for the female population either. For a lot of women, extensibility (the ability to lengthen) of the hamstrings is not the problem. The problem is the hamstrings are very weak when lengthened.

I know you'll be tempted to rationalize that the tests must therefore be unreasonably difficult. After all, if so many "normal" people fail, surely the tests and my expectations must be broken. I'll cover that later.

In the meantime, remember this. 

You need to have strength at every length.

Applying functional tests to your own dysfunctional muscles

When you fail a functional test, you know you have a problem to address. To put a more positive spin on it, you have a new skill to add to your repertoire.

You've identified something you aren't good at, and you're about to dedicate yourself to make it better.

You can run a functional test on any joint and any muscle in your body. You can challenge yourself with simple tests like:

  • Can I touch my toes?
  • Can I reach my arms straight overhead?
  • Can I squeeze my butt muscles?
  • Can I put my foot up on the kitchen counter?
  • Can I get my leg up over the top tube of my bike? Can I do it on the other leg too?
  • Can I do the front splits? 
  • Can I do the side splits?
  • Can I do a chin up?

The number of options is limitless. For advanced human movers like gymnasts, the functional tests can get far more involved and granular (although simple tests can be just as important for them).

If you're interested in testing your own body, you should choose simple movements that you fully grasp. You should know what primary muscles need to work to execute with proper form.

Don’t choose a complex, compound, and/or high-level movement to test an isolated muscle group. For example, you wouldn't choose a clean and jerk to test your glute strength. There are too many joints moving at the same time. That means a lot of muscles are working at different points in the movement. There's too much extra noise. Instead, you would pick something simple that clearly uses only the glutes within their full range (or enough of a specific range you're investigating) and without a whole lot of extra noise. 

A simple potential choice would be a glute bridge. It's an easy, low-level exercise. Over time you could increase the challenge to a weighted bridge, a single leg bridge, or a hip thrust...The point is you start easy and progress to harder tests. 

Remember to test muscles in both lengthened and shortened states. Especially around the hips, people have lots of shortened muscles. While it is important to ensure muscles are strong in shortened positions, it’s at least equally important to strengthen them in lengthened positions (if not more so). 

If you continuously strengthen muscles in shortened states, those muscles will end up weaker than you wish, and they will also start to impair range of motion at the joints they cross. Constantly training a muscle to function only in a shortened state will reduce its maximum strength output. It's also a fast track to extreme soreness and achiness in the muscle and around the joint.

biceps curl meme

If you just train bicep curls all day, you'll experience trouble straightening your elbows and moving your shoulder joint through a full range.


Muscles that are unable to lengthen will lead to poor joint range of motion and pain/discomfort. 

You need to have strength at every length. 


Choosing functional tests for your muscles

You might be thinking, “but I don’t know the metrics for what’s good enough for any given muscle!” 

There’s no need to search for double-blind placebo-controlled studies on what “perfect” is for any given muscle group.  

Any movement you see another human perform is one that you can also perform given enough time and training (I talk about it in this podcast interview with GMB). Any movement you cannot currently do is one you can improve on.

If you see another human perform a movement that you want to be able to do, start from this assumption: I can do that if I trained my muscles to do it. And follow it with this question: What muscles do I need to focus on to do that?” 

It does not matter how incredible the movement is. It does not matter how far out of reach it seems. It does not even matter if you won't even be alive long enough to train your body to do that movement. Just start investigating HOW you would get there. 

If you see someone doing a complex motion, think about how to break it down into simpler steps. 


For example:

You want to do a cartwheel? 

You don't have to jump right into it and hurt yourself! You can check on some of the preliminary steps.

  • Can you even put your arms up next to your head? If not, start there!
  • Can your hands and wrists bear your weight? If not, start there! 
  • Can you side bend without feeling like your ribs and belly will tear apart? If not, start there! 
  • Can you balance even momentarily on one leg? If not, start there! 

No matter how complex a movement looks, there are component pieces you can improve on to get closer to achieving that motion. 


WARNING: Avoid the medical propaganda on "normal" muscle function

Now, let's address "normal function." It's easy to rationalize away your muscle dysfunctions by saying, "this is normal because I see it in everyone else." It's easy to start looking for solace in the research literature.

It's also easy to say, "I need to have ironclad metrics before I start testing my own body..."

So, before you get lost in PubMed searching for peer-reviewed literature on “normal” function for muscles all over the body, let me save you some time. I want you to make progress instead of wallowing in an echo chamber of futility and feebleness. 

Let me introduce you to the Physically Feeble Fallacy.

The Physically Feeble Fallacy is simple. When we are physically feeble, we tend to rationalize and normalize it. We come up with reasons that we should allow this to continue. Sometimes we tell others that "in time, you'll be like me too."  

This is a natural tendency in all of us. We tend to see our own functional abilities as "normal." It is what we see the most on a daily basis, after all.

You've probably heard your mom, dad, and doctor say, "Yeah, going up stairs (or down stairs) is just something you can't do as you get older..." Or "yeah, my knees just don't hold up to running. No surprise, though, since humans aren't made to run!" 

It can cut in the opposite direction too. 

I once went to a handstand workshop with a talented gymnast/acrobat teacher. She had been an exceptional athlete for decades. My friend was curious about the challenges of doing one-arm handstands at the time. One-arm handstands are not easy for the average human being. It takes dedication to develop the skill. The teacher, of course, had mastered the skill years ago and still maintained the skill with ease. 

Paraphrasing the conversation... 


Teacher: "Can you stand on two feet?" 

My friend: "Yes." 

Teacher: "Can you stand on one foot?" 

My friend: "Yes." 

Teacher: "Same thing. It's not that hard." 


The teacher normalized her own abilities and didn't see (or remember) the challenges she had faced (or maybe it came quite easily to her!). And now a one-harm handstand was not something she considered challenging. 

Knowing that the physically gifted and the physically feeble normalize their own abilities, we need to reckon with the consequences for medical research...


Using medical literature to determine what is “normal” or “acceptable” for any given muscle group or movement is a terrible idea. 

The people who research “normal” are inherently biased to see their own crappy function as normal. They then conflate “uncommon” with “abnormal.” They fall victim to the Physically Feeble Fallacy. 

Put another way, if I have crappy movement abilities, I'm likely to see that as the baselineI'm highly biased to set the standard for "normal" somewhere around what I can achieve. Put me in a room with other researchers who also have crappy movement abilities, and the result is predictable. Crappy movement looks more and more "normal" because of what's "common" around us.

This is why you hear a never-ending cacophony from health professionals that sounds like this: 

  • Don't ever put your arms overhead because it's bad for your shoulders.
  • Don't look up because it's bad for your neck.
  • Don't bend at the hips because you'll hurt your back.
  • Don't lift with your back.
  • Don't stretch because flexibility is purely genetic. 
  • Don't run because it's bad for your knees. 
  • Don't jump because your body isn't designed to handle it.
  • Don't walk too far or your feet will hurt.
  • Don't let your bare feet touch the ground or your feet will hurt.

All of these warnings and statements arise from good intentions from people who are themselves physically feeble and dysfunctional.

The doctor who cannot reach overhead, look up, or bend at the hips with a strong, neutral spine will not give you good advice about those movements. He cannot understand how vital these movements are to a full and healthy life because he doesn't have these basic skills. He will rationalize those movements away as being "unnecessary."

The health professional who has never taken the time to learn how to stretch properly, run properly, and jump properly will never understand the real demands and real effects of these activities. She will say "that's too dangerous for the human body." 

The person who hasn't walked barefoot on any surface for the last thirty years has no understanding of full foot function

Medical research on human movement and "joint pain" is based on wildly outdated models of the human body. The researchers themselves rely on those models to justify their own poor physical movement abilities. As movement problems become more common, their papers paint feeble as "normal." 

“Common” and “normal” should not be the same when we think about human movement. It’s crucial to make the distinction. 

Do not fall for the Physically Feeble Fallacy!


An experiment on "normal" movement

Take a group of one hundred people and strap them into chairs for three months. Never let them get up. At the end of three months, 85% of them are unable to stand up without assistance. In this group of humans, the inability to stand from a chair is now “common.”

man sitting on a bench

We should not call that inability to stand “normal.” It is not “normal” function for a human to be unable to rise from a seated position. It is common in this group. (Let's leave aside the fact that many doctors would now pathologize this situation and claim that all these people have a disease like arthritis). 

In research on “normal” movement in humans, you will find that physical therapists and medical doctors miss the context in which their human subjects live. Humans sitting in seats 85% of their day should not be examples of “normal function.” Humans who do not regularly move in a variety of ways under varying levels of intensity will not develop or maintain “normal function.” You will simply see feeble capabilities more commonly. 


Don’t mistake being feeble for being normal. Aim to be "uncommon." 

You may see a gymnast’s abilities as abnormal. What you are actually seeing is someone with strength and mobility that is uncommon. That level of function is normal and achievable. It just takes time and practice.

You may see a martial artist doing things that are “abnormal.” You are actually seeing someone whose uncommon level of dedication created a body that is capable of performing uncommon feats. That level of function is normal and achievable. It just takes time and practice.

You may think what separates you from these uncommon people is genetics, age, or some other factor that is out of your control. The uncomfortable truth is that’s not true. It's a nice excuse that absolves you of personal responsibility. 

meme about napping

What separates people with uncommonly good movement abilities is the amount they have practiced. It’s the amount of time they’ve spent asking their bodies to move in ways that the average office worker hasn’t. 

Genetics can amplify the effects of practice, but zero guitarists became great by playing video games or studying the stock market all day. Ultimately, practice and repetition are what create competence and confidence.


What about bone shapes limiting range of motion?

Orthopedics has a tendency to blame bad bone shapes for movement problems. 

Shoulder impingement symptoms have been blamed on bad bone shapes. Hip pain has been blamed on bad bone shapes. Back pain has been blamed on "decaying" bones and other structures. Knee pain has been blamed on arthritis and meniscus tears.

Whenever researchers bother to check these theories, they discover something shocking. 

The bone shapes have no correlation to range of motion or pain. The level of bone "damage" has no correlation either. Not for shoulder impingement. Not for hip impingement. Not for knee arthritis. Not for back arthritis.

So it's more productive to just Always Think Muscles.


What about manual muscle testing to identify muscle dysfunction?

In medical and physical therapy literature, you may come across manual muscle testing as an “objective” and evidence-based method for rooting out muscle dysfunction. Muscle testing purports to give objective data on what muscles are weak and strong in a human body. 

This is half true. Here's the other half of the story...

Strength in a muscle is length and position-specific. So manual muscle tests are total bunk.

Here’s an example. 

You have Athlete A who can deadlift 200 pounds with straight knees. His hamstrings (and back) are clearly strong for that movement. 

man doing straight leg deadlift

Dramatization. Not actually 200 pounds in this image. 😂


You have Athlete B who weighs 200 pounds and can do the front splits. He holds his body’s weight using his hamstrings on the front leg and the thigh/hip flexors on the back leg. His hamstrings are clearly strong for that movement.  

man doing front splits

This is my friend Shane. He doesn't weigh 200 pounds. But he can teach you how to do the front splits (affiliate link to his program).


Now realize this: Athlete B cannot necessarily do what Athlete A can do. Nor can Athlete A necessarily do what Athlete B can do. 

They each have built very strong hamstrings FOR THAT SPECIFIC activity. There may be some small amount of carryover between these movements, but true strength and mastery of any given movement requires practice of that specific movement. 

If Athlete A also trains to do the front splits, he'll be able to do the front splits. If Athlete B also trains to do a straight-legged deadlift, he'll also be able to do that. But training one skill exclusively will not make the other "hamstring strength exercise" easy. 

And if you ask these two athletes to do an entirely different hamstring exercise that tests the hamstrings' ability to bend the knee, you'll discover almost no carryover! 

If I do a bunch of bicep curls in a standing position, it does not mean my bicep curls will be strong if I’m in a different position. This is something bodybuilders get to know quickly and something they apply when building their biceps. Muscle strength is dependent on length and position. You can’t train muscles in one orientation and expect to have good development and function in all of the lengths and angles you haven't trained.


Muscle strength is length and position-dependent. Manual muscle testing completely misses this fact.

Let’s say you test someone’s hamstring strength with a typical muscle testing method. You put them face down and have them lift their foot and leg toward the ceiling. Some textbooks will say something to the effect of, “if they can do it, their hamstrings are okay. Dysfunction is elsewhere.” 

But the muscle test only tested that one angle for that small degree of motion and with only the weight of the leg itself and some slight resistance from the tester. 

The test cannot tell us that the hamstrings are functional in all positions. Being able to lift the leg in one position does not guarantee strength in any other position.

Being able to lift the leg itself may be a challenge for the average modern human who sits all the time; however, it’s a totally arbitrary and unambitious minimum expression of strength. Since all our minimum standards are arbitrary, why should we use one that barely translates into even moderately functional locomotion? 

There are similar tests for the lateral hip as well. You lie on your side and push your leg up into a hand that provides resistance. A certain amount of resistance is considered good enough. But does that translate into other positions? Absolutely not.

Does it translate to strength in other angles? Nope.

And is passing this test enough strength if you’re trying to be a competent recreational athlete? For any sports requiring balance in a dynamic situation, the answer is no. It’s barely enough to even walk around the block with confidence. 

Manual muscle testing has the veneer of objectivity because it is somewhat objective. You can or cannot perform the requested motion. Simple and objective. However, the minimum performance to achieve “good enough” is set so low as to be pointless. And the belief that “good enough” applies to all the angles and lengths that muscle can adopt is demonstrably false. 

meme about objectivity


What’s the point of finding dysfunctional muscles and muscle imbalances?

The point of finding dysfunctional muscles and muscle imbalances is NOT to get obsessive over how broken your body is. The point is to see clearly where you can improve your body’s capacity to work, play, exert, etc.

The goal of finding dysfunctional muscles is to expand your body's capabilities in multiple realms.

matt hsu skateboarding

Rooting out dysfunctional muscles makes all kinds of activities (however random) possible. I decided to try a longboard skateboard at the age of 39.


This is where the conventional medical approach to functional tests goes so awry. Medical professionals are trained to see failure in functional tests as a sign of congenital deformity or irreversible structural damage. They are trained this way despite an endlessly growing body of history and research literature that disproves these interpretations. 

If you’re someone with chronic pain or someone who’s interested in optimizing your body’s movement capacity, muscle function matters. Assessing your abilities in this honest way gives you a constant line of fresh challenges. If you look at each dysfunction or imbalance as a new skill to acquire, you will find yourself on a journey that is physically challenging, comforting, and rewarding all at once.

  • Finding joint muscle imbalances helps you improve movement at a specific joint. 
  • Finding symmetry muscle imbalances helps you improve movement of the entire body. 
  • Finding dysfunctional muscles helps you improve your movement capabilities at the most fundamental level.

To be clear, this is not an easy quick-fix. It's a learning process. You will start with a narrow view and understanding of your body. As you test yourself, you'll learn things about your body and your life. I would type them here, but you wouldn't believe me anyway. 🙂

To keep it concrete, this process expands your abilities. It expands your physical capabilities. As you add to your repertoire, you become a human who moves right and feels right. As you move right and feel right, your confidence in your own body and in your own understanding will grow.



Ready to fix your own muscle imbalances? Learn how to fix dysfunctional muscles and muscle imbalances in this article:  “How do you fix dysfunctional muscles and muscle imbalances?” 

Train your body to be more flexible, strong, and resilient! 

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