If pain runs from your back or buttock down the back of your leg, your physical therapist may have given you a nerve glide, sometimes called nerve flossing. It looks like a hamstring stretch, but it targets a different tissue and is done differently.
Stretching a muscle is not the same as gliding a nerve
A hamstring stretch takes a muscle to the end of its length and holds it there. The sciatic nerve is different. It runs from the lower back down the back of the leg, and it has to slide a few millimetres through the surrounding muscle every time you bend your hip or straighten your knee. When that sliding is restricted or the nerve has become sensitive, a long static hold can wind symptoms up. A nerve glide moves the nerve through its pathway with as little tension as possible.
Sliders before tensioners
A slider loads the nerve at one end while unloading it at the other, so the nerve moves along its path without being pulled tight. A tensioner loads both ends at once. In a 2015 JOSPT study, Coppieters and colleagues used ultrasound to track the sciatic nerve in 15 healthy volunteers: a sliding technique moved the nerve about 17 mm, roughly five times the 3 mm produced by a tensioning technique. More movement with less strain is why sliders are the usual starting point for an irritable nerve.
What the evidence says
- A 2017 systematic review in JOSPT (Basson and colleagues) pooled 40 randomised trials. For chronic low back pain, neural mobilisation improved disability by about 9 points on the 0 to 50 Oswestry scale and pain by about 1.8 points out of 10.
- A 2023 review in the Journal of Manual and Manipulative Therapy looked at low back and radicular (leg) pain. Six of eight trials found that adding neural mobilisation to usual care improved every outcome measured, with benefits described as short term.
- Both reviews note that trials are small and methods vary. Nerve glides are part of a plan, not a cure on their own.
The seated slump glide, step by step
- Sit on a chair, let your upper back round and slump forward, and keep that slump for the whole exercise.
- Slowly straighten the affected knee while you lift your head and look up. Point the toes down as the leg extends.
- Bend the knee back down as you drop your chin toward your chest. The head and leg always move together.
- Keep it smooth, about two seconds each way, with no hold. Stop the knee short of strong pulling.
- A common starting dose is 10 to 15 repetitions, once or twice a day. Your therapist sets the number and adjusts it as symptoms change.
The rule that matters most
Mild pulling along the back of the leg is normal. Pain, tingling or numbness that spreads further down the leg, toward the calf or foot, is not. If symptoms move further from the back, reduce the range, reduce the repetitions, or stop and tell your therapist. Symptoms that stay the same or ease afterwards suggest the dose is about right.
Nerve glides pair well with gentle movement for the rest of the back; see our lower back stretches guide
Doing this exercise in a guided session
The usual mistakes at home are losing the slump and moving the head and leg out of time. A camera guided session in KineTrue can prompt the timing, record how far the knee straightened on each rep, and let you log symptoms afterwards, so your therapist can check the range against what they prescribed.
Stop and contact your clinician if leg pain, pins and needles or numbness spreads further down the leg, if you notice new weakness in the foot or ankle, or if you develop any change in bladder or bowel control. Nerve glides are not suitable for every cause of leg pain, so check with your therapist before adding them.