“Diagnosing” Muscle Tightness vs. Nerve Tension
“Diagnosing” Muscle Tightness vs. Nerve Tension
Blatant disclaimer: I’m not a physical therapist (nor do I play one on TV), so this blog post really is not meant to help “diagnose” anything in a literal sense - rather it’s meant to help you identify whether what you’re feeling during a stretch is a muscle stretch or actually nerve tension - which both should be handled differently. If you are looking for an actual diagnosis for something you are feeling in your body, please see a medical professional!
Does stretching ever get on your nerves?
No, literally - I mean when you stretch, is it putting tension on your nerves leading to discomfort and lack of progress?
Our bodies are complex sacks of meat systems of interrelated tissues, organs and structures, so it’s no surprise that when we stretch it affects more than just our muscles!
The role of our nervous system on flexibility training is something I wish I learned about way earlier in my training (because, spoiler alert, it needs to be treated totally different from our muscular system). This post is aimed to help get y’all up to speed on the basics of “neurodynamics” in flexibility training so you can start to understand the role your unique nerves play in your own personal training.
Nerves vs. Muscles in Healthy Stretching Mechanics
Nerves and muscle may work hand in hand to help us do work, but they have very different roles and respond very differently to stretching.
Muscles are relatively “elastic.” Muscles are designed to do work. They can easily elongate (stretch) and contract (shorten). You can think of them as an elastic band. If we are sitting in a piked position and start to lean forwards, hinging at the hips, our sits bones start to lift away from the floor, pulling our hamstrings even longer (like stretching out the elastic band) - this is the sensation we might identify as feeling like a stretch.
Muscles respond well to prolonged static stretching (and of course active and dynamic stretching too!).
Nerves do not like to stretch - they glide. Nerves are like the power cords of our body. Unlike muscles, nerves are relatively inelastic, but they do slide back and forth longitudinally through whatever medium they are embedded in (muscle, fascia, your spinal cord, etc). You can imagine one of your nerves like a piece of yarn sitting inside a plastic straw. If you tug on one end of the yarn, it easily slides through the straw. Likewise, in a body with healthy neurodynamics, our nerves happily glide back and forth like a piece of dental floss, and we don’t even notice a sensation.
However if we are experiencing “altered neurodynamics” where something is disrupting the ability of our nerves to slide (like a tight muscle putting pressure on the nerve, or a decrease in blood supply to the nerve), when we try to stretch our nerve can be put under too much tension, leading to sensations of:
Pins in needles or “tingling” in the extremities (hands and fingers or feet and toes)
Numbness in the extremities
Feelings of heat and cold
Feeling unusually “tight” despite stretching
Feeling a tense sensation or discomfort somewhere that is not currently being stretched (ex. feeling tension in your low back or neck during a forward fold, or feeling an intense stretch in your calves)
It’s worth noting that if you feel any of the sensations listed above, you should ease up on your stretch. Continuing to try to push into the stretch when your nerves are under tension can make actually make you more tight, or even lead to injury - nerves don’t respond well to prolonged stretching!
If you continue to feel any of these sensations after your training session (even though you shouldn’t be pushing through them in the first place!) - see a medical professional. This can be an indication of nerve damage, and continuing to stretch and tug on an aggravated nerve can make matters worse!
Common Nerves That Come Up In Flexibility Training
Common Lower Body Nerves That Experience Tension:
Sciatic Nerve
Where is it? The sciatic nerve runs from our skull, down our spinal cord, out our lower back through the outside of our hip, down the backside of our leg, under our heel to the bottom of our toes
What positions cause the most tension? Neck and back flexion (rounding the neck and spine), hip flexion (forward fold), leg extension (straightening the knees), ankle dorsiflexion (flexing the foot). Practically, this means things like forward folds, especially forward folds with feet flexed or a rounded back.
What can the tension feel like? Tension or discomfort in the low back, hamstrings, calves, or feet. The tension may feel like a stretch, tightness, tingling, or mild pain.
Related Blog Post: How to Tell if Hamstring “Tightness” is Nerve or Muscle Tension
Henry Vandyke Carter, Public domain, via Wikimedia Commons
Femoral Nerve
Where is it? The femoral nerve runs from our skull, down our spinal cord, out our lower back through the front of our hips to the front and inside of our thighs
What positions cause the most tension? Neck and back flexion (rounding the neck and spine), hip extension (flattening out the front of the hip). Practically this means things like lunges and front splits.
What can the tension feel like? Tension or discomfort in the front of the hip, hip flexors, or quads. The tension may feel like a stretch, tightness, tingling, or mild pain.
Related Blog Post: Stubbornly Tight Hip Flexors? Quick Test for Femoral Nerve Tension
Henry Vandyke Carter, Public domain, via Wikimedia Commons
Common Upper Body Nerves That Experience Tension:
Ulnar Nerve
Where is it? The ulnar nerve starts in our skull, comes out our spine in our upper back, passes through our “brachial plexus” and runs down our arm and forearm to the pinky finger side of the palm (pinky and ring finger)
What positions cause the most tension? Shoulder flexion (reaching overhead), arm abduction (pulling in toward your midline), wrist and finger extension (top of palm and fingers lifting toward your forearm)
What can the tension feel like? Tension or discomfort in the neck, chest, shoulder, upper arm, forearm, wrist or fingers (specifically the ring and pinky finger). Your ulnar nerve is what temporarily gets pinched when you hit your “funny bone” that leads to tingling in the pinky side of your hand.
Related Blog Post: Is Nerve Tension Limiting Your Shoulder Range of Motion?
Henry Vandyke Carter, Public domain, via Wikimedia Commons
Median Nerve
Where is it? The median nerve starts in our skull, comes out our spine in our upper back, passes through our “brachial plexus” and runs down our arm and forearm to the thumb side of the palm (thumb, index and middle finger)
What positions cause the most tension? Shoulder flexion (reaching overhead), arm abduction (pulling in toward your midline), wrist and finger extension (top of palm and fingers lifting toward your forearm) - very similar to your ulnar nerve!
What can the tension feel like? Tension or discomfort in the neck, chest, shoulder, upper arm, forearm, wrist or fingers (specifically the thumb, index, and middle finger)
Related Blog Post: Is Nerve Tension Limiting Your Shoulder Range of Motion?
Test to Determine if “Tightness” is Muscle-Related or Nerve-Related
Great… so one of the potential symptoms of nerve tension is “feels like a stretch” - so how are you supposed to know whether the stretching sensation you feel is a productive muscle stretch, or an unproductive tug-too-hard on a nerve?
Deduction, my friend!
The basic process for “testing” if the tension you feel is nerve or muscle related is:
Find the position that causes the discomfort and/or feeling of a stretch in the nerve and muscle you’re trying to differentiate
Example: feeling some tingling in your feet in a seated pike stretch when your feet are flexed
Move a joint somewhere AWAY from the area of the sensation that puts the nerve on “slack” but does not change the length of the muscle
Continuing the example above, we don’t want to adjust the position of our feet, ankles or knees - because that could alter the length of the muscle in the foot that may be leading to the sensation. Instead, we need to move something unrelated to the potential foot stretch to increase or decrease the nerve tension to see if it makes a difference in the sensation. In this case, you could choose un-hinging your hips (sitting back up straight). Because none of the muscles in our feet cross the hip joint, there is no muscular reason why changing the amount of hip hinge or forward fold we have would affect the sensation in your feet
If you notice a change in the sensation when you reduce (or add) nerve tension to the stretch without adjusting the muscles involved, then that’s a pretty damn good sign you’ve got some nerve tension!
How to Train with Nerve Tension
If you suspect you have some nerve tension limiting your flexibility, how do you safely train without making the tension (and your flexibility) worse?
As a reminder, we do not want to stretch nerves under tension for a long period of time - this can aggravate the nerve, cause it to increase muscle tone (the sensation of tightness) and make stretching even more difficult!
Instead, we want to…
1. Mobilize your “problem” nerves after your warm up
Nerve glides are brief exercises that can help a nerve “glide” back and forth like they’re supposed to (you can imagine these as helping “unstick” your nerve if it’s stuck). They put the nerve on tension at one end while relaxing it on the other, and then reverse - just like pulling on one end of dental floss, then the other, to help it slide between your teeth
Nerve tensioners are (also) brief exercises the gently tug on the nerve on both ends at the same time (increasing the tension in the nerve), then relax. These are useful to build up the nerve’s tolerance to tension over time, which you’ll need if you need to do moves/exercises that require the nerve to withstand a tensed position
TWO BIG GIANT DISCLAIMERS about glides and tensioners:
These are meant to be gentle, and performed in a range of motion of light sensation (NOT a full stretch!) - aim for like a 2 or 3 out of 10 intensity on a perceived excretion scale (that means these shouldn’t feel like a difficult stretch). I like to tell my students “these should be the easiest thing we do all class”
More is not better! Stick to 10-20 mobilizations per nerve per day. So if you’re doing a nerve glide for you sciatic nerve, that could mean 10-15 glides on one leg, then 10-15 glides on the other leg, and that’s it. Adding in your nerve mobilizations to training should only take a minute or two, tops!
If you do have nerve tension in one of your nerves, it can be fun to do a “pre test” of what a stretch (like a forward fold) feels like, do your nerve glides, then do a “post test” and notice if the stretch feels different. Personally I have quite a bit of sciatic nerve tension, so I’m always flabbergasted by how different my “hamstring stretches” feel (which I often feel in my calves) after doing sciatic nerve mobilizations.
2. Strengthen your end-range active flexibility to maintain healthy neurodynamics
One of the best ways to address nerve tension long-term (because nerve glides are only a temporary fix within a single training session) is to train your muscular stability at “end range” positions, positions where your nerve would typically be “on tension” to make sure all of the stabilizing muscles know how to fire appropriately to support the position. Active flexibility isn’t just beneficial to our muscles, it can help our nerves too!
3. Adjust your training to decrease time under nerve tension
Because we don’t want to stress out tense nerves by adding even more tension in a stretch or a drill, if you carry some nerve tension that might mean needing to modify your poses to put your nerves on as much slack as you can so you can focus on the muscular activity instead. So if you know you have some sciatic nerve tension, that could mean doing more work in positions with your feet pointed (less sciatic nerve tension) instead of flexed (more sciatic nerve tension), as well as being extra careful to keep your back and neck flat (less sciatic nerve tension) instead of letting it round (which leads to more sciatic nerve tension). For folks with ulnar or median nerve tension, that could mean doing more work with your wrist in a neutral position (as opposed to flexed), and your fingers in a fist (curled).
Ultimately it comes down to body awareness, listening to your body, and adjusting accordingly!
When to See a Doctor
If you have a systemic or ongoing issue, meaning you are feeling sensations of pain, tingling, etc when you aren’t stretching, please seek out a medical professional. If you know (or suspect) you have an underlying nerve issue, like sciatica or piriformis syndrome, that’s another good reason to work with a trained physical therapist and not try to DIY a training routine based on internet research. A physical therapist will be much more qualified to help you safely practice your flexibility training without aggravating your condition.
Want to Learn More?
If you liked this blog post, Dr. Jennifer Crane (aka Cirque Physio) has taught some fan-freaking-tastic workshops on the role of nerves in flexibility training (which is where I learned about neurodynamics in the first place). I would recommend her in a heartbeat as a wonderful “continuing education” resource!
