Leg muscle cramps are an interesting phenomenon. Their seemingly random onset often belies how incapacitating they can be. Similarly, preventing leg muscle cramps is often a product of hindsight rather than proactivity.
There are some widely accepted causes of muscle cramps - which we'll get to in a second. However, as a Physical Therapist, I find there may be more to the onset of leg muscle cramps than we currently realize.
Clinically, I'm finding the underlying root cause of leg muscle cramps is low-grade spinal dysfunction. And understanding this link may not only help overcome a tendency to cramp, but also provide better context for our current models of thinking.
So let's break down what I'm finding clinically and what you can do to potentially solve those leg muscle cramps.
What Are Leg Muscle Cramps?
Before we go deep into things, I'd like to provide some context.
I think it's fair to assume that most of us understand what a leg muscle cramp is. We definitely know how uncomfortable they can be! Muscle cramps are a short, intense burst of involuntary muscle contraction or spasm. They usually release on their own quite quickly but can leave lasting muscular soreness and decreased muscular function.
In theory, any muscle can cramp. But the majority of muscle cramps occur in the feet, calves, hamstrings, and forearms, and usually on the one side.
And this is important to remember, especially when linking this back to the spine.
Common Causes of Muscle Cramps
One simple question has always driven me to better understand leg muscle cramps. Why is one specific muscle group affected?
And this may not seem like a compelling question at first. But it gains more traction when we consider the more popular ideas.
While these causes make perfect sense on the surface, they always failed to answer my original question. Why does one very specific area of the body cramp?
Whether it be dehydration, electrolyte imbalances, fatigue, overuse, etc, none seem to directly explain why one specific muscle or even one side of the body cramps and others don't. They certainly don't explain why it might keep happening.
And this hunt for a deeper explanation led me to the spine. More specifically, the lower back for leg muscle cramps (and the neck for forearm and hand cramps.
Why Muscle Cramps Are Back-Related
In order to best explain what I'm finding with leg muscle cramps, I need to make another small detour.
We need to talk about the concept of muscle tone.
Muscle tone is the baseline neural activity within all skeletal muscles. This tone, which is provided by the nervous system, gives our muscles its density and shape. It allows our muscles to activate and deactivate quickly and efficiently as opposed to switching the entire system on and off all the time.
The Extremes of Muscle Tone
When muscle tone is too high, we see muscle spasticity. Conditions like cerebral palsy, brain and spinal cord injuries, multiple sclerosis, and strokes can see a severe, often permanent increase in muscle tone in areas like the calves and forearms. This increased tone makes using these muscles nigh-on impossible, seriously affecting activities like walking and using the hands. The hallmark of muscle spasticity/contracture is hard and very dense muscle.
On the other end of the spectrum, we see a lack of muscle tone associated with spinal cord injury. As a result, we see very floppy muscles with little to no tone, shape, or density.
And although a single muscle cramp is nowhere near as significant as the above conditions, they do help frame what I think we're missing as a medical industry: That muscle cramps are a temporary, yet intense "overfiring" of the nerve that supplies the muscle. One that is prompted by specific areas of spinal dysfunction.
The Dimmer Switch
As an example, think of muscle tone as a light's dimmer switch or the volume dial on a speaker. It's more practical and efficient to toggle the light up or down as needed than it is to switch it on and off every time. It allows for a more nuanced approach to getting the right amount of light at the right time.
I like to think of leg muscle cramps as accidentally knocking the dial (low back dysfunction), sharply turning up the volume (sharp increase in muscle tone), and anyone in earshot freaking out (muscle cramp).
The difference here is that I'm finding low back dysfunction at specific spinal levels relating to the muscle that cramps.
And this should hopefully make perfect sense to any therapists out there who treat nasty spinal dysfunction.
Whether it be a disc injury, spinal stenosis, nerve root compression, or general low back pain it's common to see muscle cramps if a nerve is irritated.
Essentially, the nervous system freaks out and the associated muscles do too - resulting in leg muscle cramps.
More importantly, improving these patient's back function sees an eventual decrease in muscle cramp frequency and intensity. And it's the same for those with general leg muscle cramps.
And it was these patients who helped me connect the dots between everyday leg muscle cramps and hidden low back dysfunction. We just need to extrapolate these ideas out to include those with back dysfunction, but no overt back pain.
Back Dysfunction Associated With Leg Muscle Cramps
Interestingly, my experience has shown me that you don't need nasty, end-stage back dysfunction to cause leg muscle cramps. Simple back dysfunction will do. Stiff spinal joints, overloaded discs, and overloaded surrounding tissue, etc, seem to be enough. I understand many people with back dysfunction will never experience leg muscle cramps. However, my experience has taught me that those with leg muscle cramps will have back dysfunction in the specific area relating to their cramps.
Again, that dysfunction may not be painful in any way. But its presence can set associated muscles up to cramp - given the right circumstances.
For example, the brilliant couch stretch can cause hamstring cramps at the back of the thigh - despite it being a stretch for the front of the leg. However, by hunting for and freeing up associated spinal stiffness (at the base of the spine), we can take away that tendency to cramp when doing the stretch again.
Similarly, foot cramps consistently plague people at night or in the swimming pool. By freeing up the lower back we can take away that tendency almost overnight - all without needing to address hydration, electrolytes, fatigue etc.
Now, I understand the connection between the low back and leg muscle cramps might seem tenuous to some in the absence of low back pain, but the clinical connection is impressive regardless. The results speak for themselves - as they should. At the very least, I'd hope what I'm finding can lay the foundation for more research on this topic, or provide more depth for those struggling with leg muscle cramps.
How to Treat & Prevent Leg Muscle Cramps
Unsurprisingly, our best options for treating and preventing leg muscle cramps reflect current models of thinking. We focus on hydration, stretching, massage, strength exercises, conditioning work, etc. All fantastic options of course, but potentially a little short-sighted based on what I'm finding clinically.
So here is what I think you should consider if looking to solve leg muscle cramps.
Leg Muscle Cramp Treatment Protocol
If you or someone you know suffers from persistent leg muscle cramps, try incorporating the following:
1. Spinal Joint Mobilization
This is best done by a Physical Therapist. They can assess and specifically target your exact spinal stiffness. However, a close second is using a foam roller or lacrosse ball to do the same.
The key is to use your chosen device to hunt for and press into any joint restriction you feel. Remember, restricted spinal joints react much better to stationary, direct pressure rather than rolling around - don't make that common mistake!
I've found this to be the crucial feature of solving leg muscle cramps, and hopefully you will too.
Massage to both the relevant spinal muscles and those that cramp is another highly beneficial option. It can be a great way to calm and down-regulate a heightened, threatened nervous system.
Similarly, direct massage to post-cramped leg muscles can help decrease any subsequent muscle soreness, speed up recovery, and hasten a return to normal function.
It's worth noting that we aren't talking about a deep tissue massage in either scenario here. Instead, we want one that encourages things to release, relax, and recover.
With stretching, it's important to remember that we aren't actually stretching to make our muscles more flexible. We are attempting to reclaim the normal function of dysfunctional tissue. It may sound like semantics, but it's an important distinction. In most cases we aren't attempting to go from "normal" to "better", but from "sub-optimal" to "normal". And it's no different for those who's leg muscles cramp.
The key for any good stretching program is to use the Proprioceptive Neuromuscular Facilitation (PNF) method. Couple this with a power band to bias the joint and you have a recipe to eliminate a lot of tissue restriction.
4. Strength & Conditioning
Much like massage, we want to focus on both spinal strength and improved isolated leg muscle strength. The more conditioned the better.
It's worth noting that the body prefers functional strength over isolated muscle strength. However, improved core strength (and activation), and better calf, hamstring, or foot muscle strength will certainly help buffer against the specific nature of leg muscle cramps in my experience.
Core strength exercises in the form of planks, fit ball rollouts, etc can help build a strong, robust trunk. Gluteal strength will help support normal back function.
5. Better Spinal Posture & Postural Awareness
This may not sound like a big deal but it's huge based on what I find clinically.
If low back dysfunction is the father of leg muscle cramps, consider your posture the grandfather... or perhaps the ugly step father. Either way it's important.
In short, there has to be a reason why certain aspects of your spine have become dysfunctional over time. Ask yourself the following: Why is one level of your spine stiffer than the others? Why is one side usually more restricted? In short, what has set your body up to develop the low back dysfunction associated with leg muscle cramps in the first place?
Clinically, the position you put your spine in the most - particularly when sitting, has a huge say in where you accrue dysfunction. The areas of the spine you slouch and hinge through compensate by stiffening and tightening to support that shape.
So it's vital to practice both good postures and good postural awareness. If no other reason than to make sure your hard work isn't wasted.
6. Seek Help From a Dietician or Nutritionist
Issues relating to diet and hydration may certainly influence your ability to cramp, however, they may not be the defining features. But they are aspects of your physiology that is still important to optimize.
Consider seeking professional help from a Dietician or Nutritionist to clear up any issues on this front. Drinking more fluids and eating healthier are simple concepts to try on your own, but receiving specific guidance can cut through a lot of wasted time and energy.
If you or someone you know suffer from leg muscle cramps, explore the health and function of your lower back. It may not be painful at all, but may still contribute to your cramps. My experience suggests there's every chance you'll be stiff, tight, and overloaded back there.
With this in mind, any attempts to prevent or solve leg muscle cramps need to include spinal joint mobility, core strength exercises and putting your spine in better positions throughout the day.
Other factors like improved hydration, nutrition, leg muscle strength, and conditioning certainly have their place as well based on current thinking. However, these ideas may not be the ultimate solution many are hoping for.
More importantly, focusing on better low back function may just turn a serially unpredictable and uncontrollable experience into something far less mysterious and ultimately preventable.
How have your experiences been with leg muscle cramps? What are your go-to management strategies?