Increased neural tension in the sciatic nerve can cause pain along the back and outside of your legs and feet, but it may also predispose you to getting injuries like calf strains, hamstring strains, and Achilles tendinopathy. In this article, we explain what neural tension is, what causes it, how to test for increased neural tension in your sciatic nerve, and what exercises or treatments may help. Remember, if you need more help with an injury, you're welcome to consult one of our physios online via video call.
In this article:
Please note that this article is not about sciatica, which is a different condition.
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What is neural tension or increased neural tension?
Our nervous system consists of our brain, spinal cord, and the nerves that run into all parts of the body, all the way to the tips of our toes and fingers. When we move, our spinal cord and nerves are meant to slide and glide.
Neural tension (or increased neural tension) is when a nerve is prevented from sliding (we’ll discuss what causes this lower down) and is stretched instead. Nerves don’t like being stretched; when this happens, they can cause pain or funny sensations or simply not perform their job very well.
Where is the sciatic nerve?
Our spinal cord is housed within the spinal canal, which is formed by our vertebrae that are stacked on top of each other, forming the backbone. There’s a disc made of strong cartilage between the vertebrae and also small openings to the sides (where the vertebrae rest on each other) where the spinal nerves branch out from the spinal cord. These spinal nerves then combine and fuse to become the nerves that run into the various parts of our body.
The sciatic nerve is formed by the spinal nerves that exit right at the lower part of the back as well as from the sacrum (L4 to S3 spinal nerves). It’s quite thick, as nerves go – about as thick as your thumb.
It runs through the buttock area, either underneath or through the piriformis muscle, and very close to the hamstrings along the back of the thigh. It splits at the back of the knee to form the tibial and common fibular (also called peroneal) nerves.
These nerves then further split into several branches that serve the back, sides, and front of the lower leg and foot.
Causes of neural tension
Our spinal cord and nerves slide through openings in our bones, past our joints, in between our muscles, and often over or close to our tendons. Various injuries or circumstances can cause them to get a bit stuck at any of these points:
The most common cause is simply having tight muscles and fasciae, which then don’t allow the nerves to slide freely. This can happen due to spending long periods of time in the same position or repeating the same movement. It can also happen if you train very hard without doing any mobility work.
An injury to the nerve itself will cause it to swell and generally not tolerate much tension.
Disc bulges or injuries in the back can press directly on the nerve, or swelling around the injury can increase the pressure on the nerve.
If our bones change shape, e.g. the openings in the vertebrae narrow, or perhaps you get a little bone spur (osteophyte), e.g. on your knee joint, that irritates the nerve.
The swelling and muscle tension caused by acute injuries like muscle tears or sprains can cause a temporary increase in pressure on the nerve. This is normal and usually resolves by itself if you follow the correct treatment regime for the injury.
Scar tissue or adhesions that form in reaction to other injuries, e.g. between the hamstrings and the sciatic nerve when you have high hamstring tendinopathy, can attach to a nerve and prevent it from sliding freely. This often happens in chronic injuries where someone is trying to ignore the injury and train through it, or they just rest it and don’t do any exercises to train and remodel the scar tissue. Doing the correct strength training exercises not only strengthens the area but also prevents adhesions and helps the scar tissue to form in a functional way.
Symptoms indicating increased neural tension in the sciatic nerve
None. You can have increased neural tension without it causing any symptoms. It only becomes a problem when you try and move your body into positions that actually require the nerve to slide.
Feeling of tightness or discomfort, e.g. calf or hamstring tightness that doesn’t want to resolve.
Referred pain (sharp, dull, or burning). Nerves often cause pain quite far away from the actual problem.
Strange sensations like tingling, pins and needles, or reduced sensitivity.
Suffering repetitive calf or hamstring injuries without any clear cause.
These symptoms can be felt anywhere along the line of where the sciatic nerve and its branches run.
The symptoms are often mistaken for other injuries, e.g. the fibular nerve can cause pain in the area where it wraps around the head of the fibula, which is often misdiagnosed as IT band syndrome or lower hamstring tendonitis.
Test for sciatic nerve tension
To test if the sciatic nerve is free to slide, we want to tension it all the way from the spinal cord to the toes. The simplest test is the slump test. There are many variations that a therapist can use to further pinpoint the problem, but I find that the standard test is good enough in most cases.
There is no perfect test score or gold standard that has been identified in research. The test can highlight large decreases in range of movement and differences between your left and right side, but the results should always be interpreted in combination with your other signs and symptoms.
This is how I do the slump test
This method is not appropriate for back injuries. Do not force any movements through pain – it will just make things worse.
Step 1: Sit on a sturdy chair (like a dining room chair) with your back straight and your thighs fully supported.
Step 2: Place your hands behind your back.
Step 3: Now slump forward slowly by placing your chin on your chest, then bending your upper back, and then your lower back.
What I’m looking for: At this point, I would be looking if my patient can get a nice rounding of the spine. If you notice that you struggle to keep your neck flexed when you bend the rest of your spine, or that your upper back remains straight rather than curved, it might indicate that you would benefit from mobility exercises for your back.
Step 4: Maintain this slumped position and slowly straighten one leg as far as possible while pointing your toes like a ballet dancer (plantar flexion). Observe how stiff your leg is (how far straight or not your knee can go) and whether you feel any pulling or pain in your leg, buttock, or back.
If you are able to fully straighten your leg without much pulling or pain, go to Step 6.
If you aren’t able to get your leg straight and/or feel significant pulling or discomfort in your leg, buttock, or back, go to Step 5.
Step 5: Maintain the position with your leg as straight as possible and slowly raise your head to look at the ceiling. Try not to move your back too much. Does this allow your leg to go straighter or decrease the amount of pulling you feel?
If yes, it’s a sign that you have some increased neural tension in that leg. Stop the test for this leg. Repeat it with the other leg for comparison.
If looking up doesn’t change anything, it’s a sign that the tightness, pulling, or discomfort is likely NOT caused by neural tension but rather by tight muscles. Move on to Step 6.
Step 6: Lower your leg to the floor. Make sure your chin is still on your chest and your spine still rounded. Now flex your foot and ankle up into dorsiflexion (so your toes move toward your shin). Maintain that position and straighten your leg out again. Once again, observe what you feel in your leg, buttock, and back and how straight your leg can go. Test whether looking up changes anything for you (like in Step 5).
If looking up changes things, it’s a sign that you have some increased neural tension in that leg.
If it doesn’t change anything, it’s a sign that the tightness, pulling, or discomfort is likely NOT caused by neural tension but rather by tight muscles.
Step 7: Do the test from Step 1 with the other leg for comparison.
Neural tension treatment - Common mistakes
Trying to stretch or slide the nerve when it is still stuck
It is really important to identify the most likely cause of your increased neural tension before jumping straight into doing exercises.
For example, if your neural tension is secondary to an acute disc injury or muscle tear that is causing increased swelling and pressure in that area, you should first target your treatment at those injuries. In most cases, doing the correct exercises for your back or muscle injury will also help to resolve the neural tension, and no further intervention will be needed.
You don’t need any special scans for this; an experienced sports physiotherapist will be able to identify the cause by listening to how your injury started, what your current signs and symptoms are, and getting you to do a variety of movement tests. These test can even be done via video call, and we use them regularly in our assessments.
Overstretching
You don’t need to be super flexible, and you can really aggravate your nerves by overstretching and pushing too hard.
It is absolutely normal and expected to have some level of increased neural tension; this often varies depending on the time of day or the activities you’ve just done (e.g. sitting still vs. moving around).
It is also normal for your right and left sides to not be exactly the same. When we do the slump test, we look for significant differences and whether it recreates symptoms that feel similar or are located in the area of your injury. Slight differences can often be ignored.
Exercises for increased sciatic neural tension
Whom these exercises might benefit: These are usually appropriate for people who are in the mid to later stages of rehab for acute injuries or have neural tension due to a more chronic cause. But this still doesn’t mean that these exercises are necessarily right for you, so discuss it with your physio before trying any of them.
This exercise routine is NOT appropriate for anyone:
With a recent or acute injury.
Who has something pressing directly on the nerve, e.g. disc bulge, spinal stenosis, narrowing of the openings where the spinal nerves exit, etc.
Neural tension exercise routine
I usually introduce the exercises in stages, e.g. in the first few weeks we may work on getting good mobility in the spine and around the pelvis and see how that improves things. Then we slowly work towards movements that specifically tension the nerve. How quickly we progress and what we do will always depend on what I found when I assessed my patient.
I advise doing these exercises in the following sequence, because it allows you to first loosen off the parts that could potentially hold on to the nerve before you then ask it to slide. This way, it is more likely to move without restriction.
I may ask some patients to do this daily, and others will only have to do it two or three times per week.
Standing calf stretch
Stride stand with the leg to be stretched at the back. Your toes must point straight forward.
Keep the heel of your back foot on the floor and that leg straight at all times.
Slowly bend the knee of your front leg until you feel a stretch in the calf of your back leg.
Hold the position for 30 seconds.
Switch legs and repeat on the other side.
Do twice with each leg.
Roll-down
Breathe normally throughout the movement.
Stand with your feet hip distance apart and your knees slightly bent. Your knees must remain bent throughout the movement to reduce the tension on your sciatic nerve.
Tuck your chin into a double-chin and then drop it all the way onto your chest.
Curl your spine down, starting from the top, until you’re hanging from your hips.
Allow your arms to hang loosely as you bend forward.
While in this position, wiggle your buttocks a few times from side-to-side and feel your neck and spine relax.
Take a nice deep breath and let it all out – feel how this further relaxes everything.
Reverse the movement by pulling in your stomach muscles and gently curling back up, starting from your lower back and ending with your neck until you’re upright.
Do 3 repetitions.
Arm opener
Lie on your side with your hips and knees bent to 90 degrees and your arms straight out in front of you, palms facing each other.
Lift your top arm up to the ceiling and follow it with your head as you drop it behind you. This should cause your upper body to rotate, but your hips should not roll back.
Only move to your natural restriction. Don’t try and cheat to go further by letting your arm drop towards your feet – your hand should be in line with your shoulders or higher up as you move.
You will likely feel the main stretch over the front of your chest or in the middle of your upper back.
Take a deep breath and drop your arm further down behind you as you breathe out.
Now rotate back to the starting position.
Do 3 times, then switch sides.
Piriformis stretch
Lie on your back with your legs bent and cross your right leg over your left leg.
Place your right hand on your right knee and your left hand on your right shin.
Pull with both hands so that your right knee moves diagonally towards your left shoulder. You should feel a stretch in your right buttock.
Make sure that your knee moves across your body (not straight up) and check that you also pull with the hand that is on the shin – this twists the hip and increases the stretch.
Hold the position for up to 30 seconds.
Do twice with each leg.
Figure 4 stretch
Lie on your back with your legs bent.
Place a pillow under your head if you struggle to keep your neck and upper back flat on the floor.
Place the outside of your right ankle on your left thigh, just above the knee.
Hook both hands behind your left thigh and pull it towards your chest.
You should feel the stretch in your right buttock, thigh, or lower back, depending on which part is the tightest.
Hold the position for up to 30 seconds.
Do twice with each leg.
Supine knee extension
Lie on your back with your legs straight.
Bend your left leg up so that your thigh is perpendicular to the floor and your knee is pointing at the ceiling.
Hold your thigh with your hands, but be careful not to pull it too far towards you.
Keep your foot POINTED away from you (plantar flexed, like a ballet dancer) throughout the exercise.
Slowly straighten your leg until you feel a gentle stretch – it doesn’t matter if it can’t go fully straight.
Pause for a moment and then bend your leg again (your thigh should remain perpendicular to the floor).
Do this 12 times, then switch legs.
Do 1 or 2 sets per leg.
Straight-leg plantar flexion / dorsiflexion
Lie on your back with your legs straight.
Bend your left leg up so that your thigh is perpendicular to the floor, then straighten your leg to where you can and hold it there.
Slowly bend your ankle back into dorsiflexion (toes move towards your shin) until you feel a gentle stretch in your calf. Hold that position for 2 seconds.
Point your toes away from you, so that your ankle moves into plantar flexion. Hold that position for 2 seconds.
Do this 12 times, then switch legs.
Do 1 or 2 sets per leg.
Seated slump sliders
The aim here is to slide your sciatic nerve, NOT to stretch it. So, you alternate between tensioning it at the top (neck and back), which causes the sciatic nerve to slide up, and then transferring the tension to the legs while releasing it at the top, causing it to slide down.
Sit on a sturdy chair with your back straight, your thighs fully supported, and your feet resting on the floor.
Place your hands behind our back, your chin on your chest, and flex your spine (slump position like in the test above). This tensions the nervous system at the top.
Slowly straighten one leg out in front of you (tensioning the sciatic nerve in the leg) and at the same time lift your head up to look at the ceiling (releasing tension at the top). This causes the sciatic nerve to slide down.
Lower your leg (releasing the tension in the leg) while at the same time placing your chin back on your chest (so tensioning at the top, causing the nerve to slide up).
Repeat 6 times per leg.
How we can help
Need more help with your injury? You’re welcome to consult one of the team at SIP online via video call for an assessment of your injury and a tailored treatment plan.
We're all UK Chartered Physiotherapists with Master’s Degrees related to Sports & Exercise Medicine. But at Sports Injury Physio we don't just value qualifications; all of us also have a wealth of experience working with athletes across a broad variety of sports, ranging from recreationally active people to professional athletes. You can meet the team here.
About the Author
Maryke Louw is a chartered physiotherapist with more than 20 years' experience and a Master’s Degree in Sports Injury Management. Follow her on LinkedIn and ResearchGate.
References:
Majlesi, J., Togay, H., Ãœnalan, H., & Toprak, S. (2008). The sensitivity and specificity of the Slump and the Straight Leg Raising tests in patients with lumbar disc herniation. JCR: Journal of Clinical Rheumatology, 14(2), 87-91.
Coppieters MW & Butler D. (2008). Do "sliders" slide and "tensioners" tension? An Analysis of Neurodynamic Techniques and Considerations Regarding Their Application. Manual Therapy 2008 13(3): 213-221. Web. 26 October 2013.