When is Movement “Too Much” or “Not Enough”?
In rehab, we often label movement as “too much” or “not enough”, but how do we actually know when that’s true and relevant? If you’ve ever had an injury assessment, you might have heard terms like “over-pronation” or “under-pronation.” Maybe you have too much knee valgus when you squat, your low back is hypo-mobile, your pelvis is out of alignment, or maybe it’s poor posture. The problem with many of these descriptors is that they’re largely subjective - no therapist can actually measure joint movement simply by watching you. These terms are often used to explain pain or injury, but the relationship between movement and pain is far less clear than many people assume.
Much of this comes from the concept of an “ideal.” Ideal technique, ideal posture, ideal mechanics. Anything different gets labelled “dysfunction”. The implication is that every person should move a certain way, and if you don’t move in this “optimal” way, something must be wrong and needs fixing. These explanations are often used to justify specific corrective exercises. But this approach is overly simplistic and ignores the natural variability in human bodies and pain experiences. There is certainly more discussion to be had around movement when it comes to performance — efficiency, skill, and sport-specific technique — but here we’re focusing on injury and pain.
Even if we did hook someone up to a biomechanical analysis system and measure joint angles during movement, the question still remains: when does movement become too much or not enough? Textbooks provide average ranges of motion for joints, but that’s exactly what they are — averages. What we don’t have are clear standards for when variation becomes a problem. At extreme ranges there would probably be agreement that someone has “poor posture.” But posture exists on a spectrum. At what point does it actually become “poor”? And even then, we still have several steps before confidently saying that over-pronation is the cause of your foot pain and must be corrected for you to recover.
How Are Movement Dysfunctions Measured?
Often, we simply use our eyes when assessing how someone moves. I’m certainly guilty of this. It’s jokingly call it the “vomit test”: if watching someone move makes me want to vomit, I’ll take note. Very objective and scientific (sarcasm). In reality, this is more about noticing large movement differences rather than tiny variations. There are objective tools that can improve accuracy — a goniometer to measure joint angles, a dynamometer to measure force, or slow-motion video. But even with objective data, we still face the same question: how much is too much? We simply don’t have reliable, consistent data showing that a specific angle — say 25° — suddenly becomes “over-pronation.”
Do These Movements Dysfunctions Actually Cause Pain?
Many biomechanical explanations follow a common-sense logic. It seems reasonable that there would be an ideal way to move, and any deviation would be less ideal. It also seems reasonable that someone’s flat foot might contribute to pain while running because of increased stress on the bottom of the foot. These explanations pass the common-sense “sniff test,” which is likely why they persist. But plausible explanations are not always accurate, especially when dealing with complex human systems.
Do People With Pain Actually Show These Dysfunctions?
This is where things become less clear. Research often contradicts what seems intuitive. For example, it seems logical that poor posture would lead to back pain. But we see people with poor posture who have no pain, and others with excellent posture who do have pain. Sometimes the relationship may even run the other direction - pain can influence posture. Someone with disc-related back pain may shift their torso sideways simply because it reduces symptoms. In that case, the posture isn’t the cause of pain but a response to it.
Can These Movement Patterns Actually Be Changed?
Many treatment approaches focus on correcting these perceived dysfunctions through specific exercises. These are typically highly cued, low-load “motor control” exercises designed to help you feel and control certain movements or positions. The idea is that repeating these exercises will eventually correct the dysfunction and resolve the pain. But research often shows that these movement patterns don’t actually change — even when pain improves. So what caused the improvement? Was it the exercises themselves? General physical activity? Natural recovery? Expectations about the treatment? Pain and movement are complex systems, and rarely explained by a single factor.
Do You Need to Change Your Movement to Get Out of Pain?
This is the real question, and the heart of my position. Humans are highly individual in how they move. We naturally develop movement patterns that feel comfortable and efficient for us. Do we really want to change what is natural for every individual? Usain Bolt, the fastest man in the world, has noticeable scoliosis. Through training, he has adapted to it while setting world records in the 100 metres. If we tried to “correct” his scoliosis, would that make him faster — or slower? Many elite marathon runners display foot mechanics that many clinicians would label over-pronation (in fairness, I probably would too). Yet they perform at the highest level. Would it make sense to change the very mechanics that got them there? This situation occurs frequently in rehab. A runner develops knee pain, completes rehabilitation, and their pain resolves — yet they continue running exactly the same way as before. If they entered and exited pain without changing their running mechanics, can we really blame the mechanics? Sometimes we do temporarily change movement patterns, but not because the movement itself is faulty. Instead, the goal is to unload a sensitive structure. Once symptoms settle, we gradually build capacity again.
This is why I’m skeptical of the over/under and hyper/hypo labels for posture and movement. Often the measurement isn’t reliable, the link to pain isn’t clear and many of these “dysfunctions” either can’t be changed or don’t need to change for pain to improve. I understand the appeal of this idea: fix this dysfunction and you’ll fix your pain. It’s simple and reassuring, but it can also create misleading narratives. People start to believe their bodies are fragile. They worry that moving the wrong way will cause injury. Small aches lead to fear, avoidance, or compulsive corrective exercises. Ironically, letting go of the need to fix every perceived dysfunction often opens more options in rehab. It shifts the focus towards building strength, tolerance, and confidence in movement, rather than chasing perfect mechanics. This is usually what gets people back to doing what they enjoy.
(Credit goes to Greg Lehman’s Reconciling Biomechanics with Pain Science for the inspiration for this blog and this thought process that helped me develop into the therapist I am today.)
