Physical therapy patients are often told that a “muscle imbalance” is to blame for the pain and movement limitations that are troubling them. But what is a muscle imbalance, exactly?
“Quad Dominance”
We’ll begin to answer this question by covering a very common muscle imbalance called quadriceps (or “quad”) dominance.
Quad dominance describes the relationship between two muscle groups. Above the front of the knee are the quadriceps, or quads, and above the back of the knee are the hamstrings. The quads straighten the knee and the hamstrings bend it. We call the quadriceps/hamstrings an agonist/antagonist pair, because one muscle opposes, or antagonizes, the other.
During fast movements – such as kicking a ball – when the quads are “on”, or contracting, the hamstrings should be “off,” or relaxing. To rapidly straighten the knee to kick, we need the quads to turn on very quickly and powerfully, and we need their antagonists, the hamstrings, to cooperate by turning off very quickly.
Muscle imbalance occurs when one group of muscles is consistently stuck “on” and its antagonist stuck “off.” At the knee, the quads are frequently stuck “on” and the hamstrings “off.” The quadriceps are dominating the relationship with their antagonists – the hamstrings. Such dominance typifies muscle imbalance.
Non-binary
But of course, we’ve over-simplified by using the binary descriptors of “on” and “off.” In reality, muscle tone is continually modulated in accordance with the complex demands of moving our bodies in the world. Apart from quick, violent movements like a kick, agonist/antagonist pairs rarely function in such an on/off, contract/relax fashion.
It’s more accurate to think of our muscles as each having a volume control, and our brain acting something like a mixing board. You can imagine each muscle having a knob that’s adjustable from 1 to 10 – from a very quiet contraction (volume = 1) to a loud, powerful clench (volume = 10).
Muscle Mixing Board
Using this analogy, we might say that our quads tend to operate in the volume range between 6 and 10; meanwhile, while our hamstrings tend to under-function in the range of 1 to 5. While neither is completely OFF (zero) or ON (ten), most of the time the quads are dominating the hamstrings. It’s not supposed to be like this.
Quad dominance results in aberrant strain across the knee joint, and is associated with various types of knee strain and injury, both acute and chronic/overuse. Ideally, normally, our brains should have full ability to change the volume of both the quads and the hamstrings, from relaxation (zero) to maximal contraction (ten), depending on the needs of movement and moment.
Searching for Balance
Correcting this type of imbalance is tricky. Historically, physical therapists have employed a “stretch and strengthen” approach borrowed from athletic training. Using this strategy, we might do stretching exercises with the goal of making the quads longer, and strengthening exercises to make the hamstrings stronger and more active.
Unfortunately, this doesn’t work very well. The hamstrings will probably get stronger, but during real-life movements they might not act like it, because their volume knob is still stuck below six. And although we might succeed in stretching out the quads and making them act a bit longer, the stretching effect doesn’t last. After a little while, the quads go back to their habitual use pattern – being stuck at high volume. They might put on a nice show during stretching sessions – lengthening a bit in response to sustained stretches – but in real life action, they haven’t changed much. The muscle imbalance remains.
Why doesn’t the stretch + strengthen paradigm work?
Well, there are several reasons; here are two: The first is a communication problem. Neither traditional stretching nor strengthening are very effective forms of neuromuscular communication.
The second is a scale problem. In reality, quad dominance is not really a problem affecting only a single joint. While it is easiest to see the effects of quad dominance at the knee joint, overly active quads and underachieving hamstrings also affect the hip joints, above the knees.
Furthermore, neither stretching the quads nor strengthening the hamstrings address the real cause of the imbalance: our muscles are adapted to our habitual posture, breathing and movement patterns. Unless we change these patterns, stretching and strengthening single pairs of muscle is unlikely to result in lasting change, or in relief of symptoms.
Everything is connected to everything else
You’ve probably heard of the kinetic chain, and how everything is connected to everything else in the body. This is true anatomically, neurologically, and also with respect to posture and function.
For instance, the hamstrings and quads have more to do than just bend and straighten the knee. As mentioned, muscles in both of these groups also cross the hip joints. The hamstrings straighten (extend) the hips, and the quads bend (flex) them.
And above our hips is our spine, with its own orchestra of muscles acting to move not just the spine, but also the pelvis and hips from above.
The quads and hamstrings don’t exist in isolation. When muscles above and below them shorten or lengthen, they must adjust, and vice versa. If one muscle pair develops an imbalance, the muscles above and below invariably will as well.
And so it is that the volume controls of whole chains of muscles become stuck at high volume, and chains of their antagonists get stuck at low volume. Muscle imbalance now comes into focus as not a matter of only a pair of muscles, but of all our muscles!
To illustrate, in quad dominance the hamstring volume is low and the quad volume is high. In this situation, the louder quads pull the front of the pelvis down and forward, and the quiet hamstrings allow the back of the pelvis to rise up and tip forward. The net effect is called anterior pelvic tilt, which usually coincides with a deepened lumbar curve, or hyperlordosis. Taken together, the anterior pelvic tilt and lumbar hyperlordosis result in another muscle imbalance: short and tight low back muscles paired with quiet and sleepy abdominal muscles.
And it doesn’t, indeed can’t, stop there.
Continuing up the chain, in response to the hyperlordotic lumbar spine and quiet abdominals, the ribcage elevates in front and the thoracic, or middle part, of the spine correspondingly flattens. This changes the shape of the diaphragm, reducing its effectiveness as a breathing muscle. And so the neck muscles begin to help with breathing by lifting the ribs and collar bones up. The tight neck muscles pull the head forward, which results in imbalance of the muscles in the neck, jaw and head.
Looking at the problem through the frame of posture, we can see how stretching the quads is unlikely to be a lasting solution to a quad-dominant muscle imbalance. Even if we stretch the quads, the low back muscles will still be tight and loud, and the abdominal muscles will still be quiet and long, and so the anterior pelvic tilt will remain. And even if we stretch our low back muscles, our chests will remain elevated in the front by our tight neck muscles.
We can see how stretching and strengthening a single muscle pair is doomed to fail. It may be our knee that hurts, and though quad dominance might be primarily to blame, the volume of those muscles is interdependent with the volume of muscles in the pelvis, back and even the neck. We can’t really change anything without changing everything.
Whole Body Postural Events
Muscle imbalance tends to be a full-body event, with entire chains of muscles over- or under-functioning. Therefore, resolving muscle imbalance permanently requires adjustment of the volume controls for whole chains of muscles.
How do we do that? As we’ve seen, traditional stretch/strengthen protocols won’t get the job done. Historically, there have been many attempts to adjust these body-wide muscle imbalances. Many of these approaches have focused on changing posture as a way to resolve system-wide muscle imbalances, and thereby improve movement patterns.
Vladimir Janda
In the tradition of academic physical therapy, the work of Czech neurologist Vladimir Janda was revolutionary.
The most important advances in this field have come from those who originally trained and worked outside of it. Janda was a neurologist, and brought a fresh perspective and a revolutionary, whole-body conception of muscle imbalance to physical therapy in the 1970s.
His “Lower Cross Syndrome” described the network of imbalances outlined above at the knee, hip, pelvis and lumbar spine for the first time. And his “Upper Cross Syndrome” laid out the muscle imbalances that accompany the rounded shoulders and forward head postures ubiquitous in our modern era.
As is often the case, identifying a problem may only hint at effective solutions to that problem. Attempting to restore balance to people suffering from upper and lower cross syndromes has frustrated many physical therapists employing stretch + strengthen approaches.
But over the past twenty years or so, several physical therapy methods have been created to successfully resolve the problems that Janda identified five decades ago. These approaches have gradually become more accessible to patients in recent years.
Breathing: The missing link
The key to these new methods is the recognition of the crucial role that breathing plays in creating and sustaining muscle imbalance. Essentially, the muscle imbalance syndromes identified by Janda can be seen as breathing pattern disorders.
Because breathing is the activity that we must always be doing, any meaningful and long-lasting change of muscle imbalance, posture or movement patterns must involve changes in our breathing patterns. In the body, all roads lead to, through, and from breathing.
Dynamic Neuromuscular Stabilization
Pavel Kolar, the current director of the rehabilitation school founded by Vladimir Janda in Prague, has devised a new way of treating muscle Janda’s muscle imbalance syndromes. His method of Dynamic Neuromuscular Stabilization (DNS) teaches diaphragmatic breathing as its core element.
Diaphragmatic breathing is the key to successfully treating and resolving upper and lower cross muscle imbalance syndromes, and as explained in a previous blog post, diaphragmatic breathing = core stabilization.
Like Janda, Pavel Kolar brought insights from another branch of medicine to illuminate unsolved problems in orthopedics and physical therapy. Kolar’s DNS is founded in his work in pediatrics, and in particular the study of the developmental movement sequence that all of us progressed through in our childhood journeys from rolling and crawling to standing and walking.
Kolar observed that some children progress through the developmental movement sequence (rolling, crawling, standing, and ultimately walking) in a more effective way than others. While some toddlers employ diaphragmatic breathing as a means to both breath and to stabilize their “core”, allowing them to roll and crawl in a healthy, integrated way, other toddlers begin to demonstrate signs of imbalanced movement and muscle activation patterns early in life. Essentially, these children do not learn how to use their diaphragm for both breathing and postural stabilization.
Consequently, these kids struggle with the developmental movement sequence, tending to overuse the very muscles that Janda identified as being overactive in his Upper and Lower Cross Syndromes. While most of these children do eventually progress to standing and walking, they often go on to demonstrate Janda’s muscle imbalance syndromes during their childhoods and on into adulthood.
To resolve these imbalances in children and adults, DNS teaches diaphragmatic breathing as both a breathing and core stabilization strategy. This strategy is then employed to re-learn and practice movements and elements of the developmental movement sequence, but in the correct way this time, thereby resolving the patterns of muscle imbalance and unhealthy posture that Janda identified.
Postural Restoration
Ron Hruska, the founder of the Postural Restoration Institute in Lincoln, Nebraska, has created a method for the sophisticated diagnosis and treatment of patterned muscle imbalance.
Central to Postural Restoration is the concept that everything that the arms and legs do – while walking, standing, dancing, playing sports – is reflected in movements of the ribcage. In turn, movements of the ribcage define, and are defined by, our breathing.
Using the Postural Restoration method of physical therapy, therapists at FuncPhysio teach patients to sense and modify their breathing while practicing progressive therapeutic activities that simultaneously turn down the volume of tight, overworked muscles, while turning up the volume of quiet and under-utilized muscles.
Breathing: A New Answer to Old Questions
Breathing exercises have been practiced in various cultures for hundreds, if not thousands, of years. What makes Postural Restoration different is the recognition that airflow and air pressure inside our lungs and trunks must be balanced from front to back, and also must alternate from side to side.
For instance, our hamstrings will forever be weak if we breathe by lifting our chests up in the front and down in the back. This breathing pattern – called chest breathing or neck breathing – is extremely common in our modern era. By learning to exhale fully in various positions, we quickly learn to turn down the volume (or “inhibit” in neurological terminology) of the muscles we’ve been relying on too heavily (like our low back and neck muscles), and turn up the volume of (or “facilitate”) the muscles we hardly ever use (like our abdominal obliques and hamstrings).
And by learning to inhale in these same positions, a self-sustaining re-patterning circuit is created: every breath we take then serves to maintain and support the new postural pattern. A key similarity between Postural Restoration and DNS is a common emphasis on diaphragmatic breathing.
The Genius of Postural Restoration
But the genius of Postural Restoration is in the resolution of imbalances between the left and right sides of our bodies. These asymmetrical patterns were first identified by Mr. Hruska, and are now known to cause or contribute to many injuries and imbalances that are uni-lateral, or affecting only one side of the body.
Why does my right knee hurt, but not my left? Why has the arch of my left foot fallen, but not the right? Why are the muscles on the right side of my head and neck always tight, and is this related to my chronic, right-sided headache?
Postural Restoration offers answers to these questions. By re-learning to alternate breathing pressures from left to right, these side to side differences, and the aches, pains and injuries caused by them, can be balanced and healed.
Tri-Planar Muscle Imbalances/Asymmetries
Janda’s upper and lower cross syndromes can be seen as asymmetries between the front and back of the body, or occurring in what we call the sagittal plane. In the sagittal plane, the quads are tight and the hamstrings are weak, the low back muscles tight and the abdominal muscles weak. But muscle imbalance also exists in the other two planes of motion. We can call this asymmetry
While some people do have tight low back muscles and weak abdominal muscles on both sides of their bodies – lower cross syndrome – most of us have weaker abdominals on our left side than on our right. And while it is true that many people have weak hamstrings, most of us will find that it’s our left hamstrings that are the weaker. Most of us can breathe diaphragmatically to our left lung, but we use our neck muscles to pull air into our right lung.
The Elusive Obvious
This may sound odd, even incredible. Although these patterns of asymmetry are indeed ubiquitous, they were virtually unknown until Hruska began to identify them twenty years ago. In my opinion, this is an example of what movement educator Moshe Feldenkrais called “the elusive obvious.” The patterns of asymmetrical muscle tension, posture and movement imbalance studied by the Postural Restoration Institute were hiding in plain sight. Once seen or felt, they become impossible to ignore.
Left to Right Antagonism
Just as the quads are antagonistic to the hamstrings in the front/back, or sagittal, plane, muscles on one side of the body also work in opposition to the same muscle on the other side of the body.
For example, the hip adductor, or inner thigh muscles, are frequently tight, nearly spastic, in our right leg, but quiet and barely functional in our left leg. Why?
Ron Hruska discovered that most, if not all, of us, are biased heavily toward our right side. This bias, which is both anatomical and neurological in origin, results in fundamental asymmetries in the way we sit, stand, walk, and breathe.
In essence, the right and left sides of our bodies are specialists, each side being good at what the other is not. This means that chains of muscles on one side of the body are tight and loud, while those same muscles are quiet and sleepy on the other side of the body. These chains include muscles responsible for the shape and function of the ribcage on the two sides of the body. The way we breathe, too, is asymmetrical, and the asymmetry of our breath reflects and reinforces the asymmetries in the way we use our muscles.
When standing and walking, nearly all of us tend to lean toward our right foot. This results in our pelvis and lower spine rotating to the right. The chain of muscles that perpetuates this imbalance is called the Left Anterior Interior Chain (L AIC). Muscles of the L AIC on the left side of the body are short and tight, while the same muscles on the right are correspondingly long and loose. You can read more about this pattern of imbalance here.
With our lower body twisted to the right, our upper spine, ribcage and shoulders counter-rotate to the left to keep us moving forward rather than veering off to our right, and also to help pull air into our right lung. This counter-rotation is maintained by excessive tension in the Right Brachial Chain of muscles (R BC).
The neck and head must compensate for this twist by counter-twisting to keep our gaze in the direction we’re moving. This requires excessive tension in a pattern called the Right Temporomandibular Cervical Chain (R TMCC).
Restoring side to side and rotational balance
For many patients, Postural Restoration treatment begins with balancing the front and back of the body in the sagittal plane. This resolves lower cross syndrome by restoring diaphragmatic breathing. And in so doing, we unlock our freedom to shift our weight freely from side to side (in the frontal plane), and to rotate our hips, spine and neck in the transverse plane.
We then might find that our right hip is better at rotating in than out, and that the opposite is true of the left hip – both being manifestations of the L AIC pattern. We may also find that our right shoulder sits lower and more forward than our left shoulder – indications of the R BC pattern.
Postural Restoration treatment proceeds to restore balance to these muscle chains by teaching the left side of our body to do what right is good at, and vice versa. This involves learning to turn down the volume (inhibit) of the muscles of the L AIC and R BC, which clears the way for the same muscles on the other side of the body to turn up their volumes and re-learn their jobs.
And during every exercise and activity, we practice a simple diaphragmatic breathing technique (inhale through the nose, exhale through the mouth), for the most important change and education that occurs in balancing the body in all three planes is balanced and alternating movement of air and pressure through both sides of the ribcage, and through both lungs. Learning new movement patterns is difficult, but when we can breathe deeply and comfortably in the new pattern, we own it.
Teaching the left side of our body to move and breathe like our right side restores our ability to alternate from side to side, in comfort, and without excessive muscle tension. Restoring our ability to harmoniously shift our centers of mass and lung pressures from side to side restores symmetry to our walking and our running.
Many injuries and impairments can be seen as the result of accumulated, repetitive stress caused by asymmetrical movement patterns perpetuated by muscle imbalance. Restoring our ability to walk, run and move harmoniously and symmetrically removes this repetitive strain, and often allows injured, inflamed tissues to rest, heal and recover.
