The Myth of Uneven Leg Length
Your doctor or chiropractor may have told you that you have one leg longer than the other, and that your leg length discrepancy is the cause of your back, hip, or knee pain. The truth is that while it’s certainly possible to have one leg longer than the other, the odds of your leg length discrepancy being significant enough to cause you pain are extremely small.
When doctors and chiropractors diagnose you with leg length discrepancy, most often it’s because you’re hiking one hip up higher than the other. That’s right—it’s not the length of your leg bones that’s causing your uneven leg length. Most likely, the muscles in your waist, lower back, and hip have become chronically tight on one side, and these tight muscles are laterally tilting your pelvis.
Most of us have a dominant side of our body, and we use that side in different ways than we do our non-dominant side. For example, I’m right-handed, and when I was a ballet dancer I practiced movements more often with my right side than my left. I also had the habit of standing with all my weight on my left leg.
In photos of me as a teenager you can see my right hip hiked up higher than my left, and this posture stayed with me into adulthood. I remember stepping on and wearing away the bottom hem on the left leg of my pants, while the right hem stayed perfect. If I had ever sought out a diagnosis, undoubtedly the answer would have been uneven leg length.
When I began training in Clinical Somatic Education and learned how to release the chronic tightness in my obliques and my iliopsoas, my hips evened out, and all of a sudden my legs were miraculously the same length. The pain in my left hip went away too!
The anatomy of functional leg length discrepancy
If your length length discrepancy is functional, it means that it’s not a structural issue—it’s a result of how you’re using your body. Functional leg length discrepancy may also be diagnosed as lateral pelvic tilt or pelvic torsion.
At the root of functional leg length discrepancy is chronic tightness in the quadratus lumborum, internal and external obliques, and iliopsoas. These are all strong core muscles that laterally tilt the pelvis and provide essential core stability in full-body movements. Since we use them so much, it’s very easy for them to become chronically tight as a result of overuse and imbalanced movement patterns.
When you have functional leg length discrepancy, other back muscles that laterally flex the spine (bend the spine to one side) will likely be tight as well, including the longissimus, iliocostalis, and latissimus dorsi. If your lateral flexion progresses to more than 11 degrees, it may be diagnosed as scoliosis.
Our entire body is connected like a pulley system. When one part moves out of alignment, the rest of our body will adjust to balance us out. So, if you’re hiking one hip up, you’re likely compensating for this misalignment by shifting other parts of your body out of alignment as well.
For example: If you’re hiking your right hip up, you may be shifting your weight to your left side, and the left side of your rib cage might be pulled down toward your left hip. So, the muscles on the left side of your waist and lower back and in your left hip will be tight too—just in a different pattern than on your right side. They’ll be pulling your rib cage downward instead of hiking your hip up.
Another way we compensate for lateral pelvic tilt is by rotating our body in various ways. It’s very common to have some rotation of the hips, pelvis, and spine along with functional leg length discrepancy.
Here’s an example: If you’re using your right and left sides differently, and standing with more weight on one side than the other, you can easily develop lateral (outward) rotation on one side and compensating medial (inward) rotation on the other. You might inwardly rotate the hip that you tend to lean on, and outwardly rotate the hip that you’re hiking up. Your gluteal muscles will likely become tight on both sides as a result of this rotation, because different parts of our gluteal muscles rotate our hips both inward and outward.
In this pattern, your internal rotators and adductors (the muscles on the inside of your thighs that pull your legs together) will become tight on the side that you’re leaning on and rotating inward. These muscles attach to the bottom of the pelvis, so they can pull your pelvis downward on that side, exacerbating your overall pattern.
If your lower hip is inwardly rotated, your tensor fascia latae on that side will become tight, creating tension in your iliotibial band. This tension, along with increased body weight being put on this side, can easily lead to knee problems.
Pelvic torsion also commonly occurs with functional leg length discrepancy. This describes the misaligment of the pelvis when one side is tilted forward and the other is tilted backward.
The pelvis can also be rotated on the transverse plane (imagine a Lazy Susan). So, one hip might be pulled forward while the other is pulled backward.
This twisting will continue up our spine; our obliques, multifidi, and rotatores will become tight, rotating our vertebrae and leading to adjustments in our upper body. We may pull one shoulder backward and the other forward, pull one shoulder downward and the other upward, and turn or tilt our head to one side.
Full-body patterns of posture like what I’m describing begin in the core of our body; this is where our strongest muscles are located and where we initiate movement. Movement of our arms and legs are extensions of the movements that begin in our core. So, while we might experience misalignment, pain, or other symptoms in various areas of our body, it’s extremely important to address the root cause of our problems by releasing chronic tension and imbalances in our core muscles. (I’ll talk about how to do that in the last section of this post).
Conditions caused by or related to functional leg length discrepancy
Due to the way we subconsciously adjust our posture and movement to accommodate functional leg length discrepancy, uneven stress can be put on many parts of our body, leading to the following conditions:
- Hip problems, including pain, tendinitis, bursitis, and osteoarthritis
- Iliopsoas syndrome
- Knee problems, including pain, tendinitis, bursitis, osteoarthritis, and recurring injuries
- Iliotibial band syndrome
- Stress fractures
- Ankle problems, including pain, tendinitis, and recurring injuries
- Foot pronation or supination
- Lower back pain
- Idiopathic scoliosis
- Disc degeneration
- Tightness and pain in the neck and shoulders
Why do we develop the chronic muscle tightness that hikes one hip up?
So, how and why do our waist, back, and hip muscles become tight enough to cause functional leg length discrepancy? And why does it happen to some people and not others?
The movement and level of contraction of our muscles is controlled by our nervous system. The way that our muscles move, and how much we keep them contracted, is actually learned over time by our nervous system.
Our nervous system learns certain ways of using our muscles based on how we choose to stand and move each and every day. Our nervous system notices the postures and movements that we tend to repeat, and it gradually makes these postures and movements automatic so that we don’t have to consciously think about them.
This learning process—that of developing what we refer to as muscle memory—allows us to go through the activities in our daily lives easily and efficiently. Unfortunately, if we tend to repeat unnatural postures or movements (like practicing my dance moves on my right side, and standing with all my weight on my left leg) our nervous system will learn those too. Our automatic neuromuscular learning process doesn’t discern what is good or bad for us—it just notices what we tend to repeat, and makes it automatic.
So if you carry your bag on the same side every day, hold your child on the same hip, kick a ball with the same leg, or sit at your desk in the same way—your core muscles can easily become tighter on one side than the other, leading to functional leg length discrepancy.
As your nervous system gradually learns to keep your muscles tight, gamma loop activity adapts. This feedback loop in your nervous system regulates the level of tension in your muscles. As your brain keeps sending the message to contract your muscles, gamma loop activity adapts and starts keeping your muscles tight all the time. Meanwhile, your proprioception (how you sense your body) adapts so that you’re not aware of the increased level of tension in your muscles.
How to use Clinical Somatics exercises to alleviate functional leg length discrepancy
So, can we change our learned muscular patterns, restore normal gamma loop activity, and retrain our proprioception? Yes, we can! The movement technique of pandiculation allows us to do all of these things by sending accurate feedback to our nervous system about the level of tension in our muscles. Since this is already a long post, I’ll let you read more about pandiculation in this post.
If you’ve learned Clinical Somatics exercises from my online courses or from another Certified Clinical Somatic Educator or Hanna Somatic Educator, you can use this section to help guide you in releasing the muscles that are causing your functional leg length discrepancy.
First, some general advice:
Identify which hip is higher. As I mentioned in the anatomy section, both sides of your body are tight—they’re just tight in different ways. This may sound obvious, but you’ll probably experience better results by first focusing on releasing the muscles that are hiking your higher hip up.
So as you practice the exercises, start by spending more time working with the side on which your hip is higher. Some days, try lying down and practicing the exercises only with that side. When you stand up, you’ll feel unbalanced, but that’s part of the learning and adjustment process that your nervous system needs to go through. Be sure to do the Standing Awareness exercise before and after—this is a critical part of the process of adjusting your proprioception.
As you begin to balance out your hips, you’ll become aware of the different patterns of tension you have on each side of your body, and you’ll figure out how to work with each side to release that tension.
When you do practice the exercises on both sides, notice how each side of your body feels different. Are you using your muscles differently? Can you sense your muscles more on one side than the other? Do you feel like you have more control on one side than the other? Is one side tighter or looser than the other?
You can then go back and forth from side to side, learning from your more coordinated side. If a movement feels easy or “right” on one side, try to replicate that feeling and way of moving on your other side.
Now, some specific exercises. From the Level One Course:
Back Lift: To release your lower back and gluteal muscles on your “higher-hip” side, turn your head to look away from that side. So, when doing the full movement you’ll be lifting up the leg on your higher-hip side.
Side Curl: This is a very important one for you to do every day. Lie down on the side of your lower hip, and practice this curling up to the side of your higher hip. Many people have difficulty sensing and releasing their obliques at first, so be patient with yourself. Really try to get a sense of the muscles on the side of your waist contracting, then release them as slowly as you possibly can—resist gravity as you lower down. Completely relax for a few moments before repeating the movement.
One-Sided Arch & Curl: To work with your higher hip, lift up your knee on your higher-hip side.
Iliopsoas Release: This is another very important one to do every day with the hip that is higher. Take it slow and be gentle—this can be an intense movement if your iliopsoas is tight.
Hip Slides and Hip Raises: These offer a wonderful opportunity to go back and forth from side to side, compare the differences between your two sides, and learn from your more coordinated side. You can also practice these only with your higher-hip side if you wish.
Hip Rotation: Explore these movements to figure out if your hip rotators are unevenly tight. For example, if your right knee moves out to the side easily, but your left does not, then spend some extra time gently lowering your left knee out to the side using the Internal Rotator Release.
Finally, be aware of how you’re using your body as you go through your daily life. Your progress with the exercises will be slower if you continue to do activities or habitual postures that are keeping you stuck in your patterns of tension.
Notice how you use the sides of your body differently when you:
- Stand for a few minutes: do you lean to one side?
- Carry your bag
- Carry your child
- Drive your car
- Work on a computer
- Use your phone
- Sit to read or watch television
- Sleep: do you sleep more on one side than the other?
Ready to start learning?
If you’d like to learn Clinical Somatics exercises at home, the best place to start is the Level One Course. This online course teaches the exercises through video demonstrations, audio classes, and written explanations.
If you’ve been diagnosed with scoliosis, you can start instead with Clinical Somatics for Scoliosis.