You’re lying face down, a thin needle slides into the knot in your upper back, and suddenly the muscle jumps — a quick, involuntary flinch you didn’t tell it to make. Your first reaction is probably “what was that?” Your second, a moment later, is often “huh… it feels looser.”
That jump is called the local twitch response, and it’s the heart of how dry needling works. At Lakeside Spine & Injury Center in Wheat Ridge, Dr. Andrew Allen, DC explains it to patients every week — because once you understand what the twitch is doing, dry needling stops feeling mysterious and starts making sense.
First, What Is a Trigger Point Actually Doing?
To understand the reset, you need to understand what’s stuck. A muscle is made of thousands of tiny contractile units called sarcomeres. Normally they contract when you ask and relax when you’re done. A myofascial trigger point is a small cluster of sarcomeres that got locked in the “on” position and never received the signal to let go.
That locked cluster becomes a taut band you can feel under the skin. It also creates a nasty local environment:
- Constant contraction squeezes the tiny blood vessels that feed the area, reducing oxygen and nutrient delivery.
- Energy demand stays high while supply drops, so the sarcomeres can’t get what they need to release — a self-sustaining loop sometimes called the energy crisis model.
- Irritating chemicals accumulate — research sampling the tissue around active trigger points has found elevated levels of inflammatory and pain-signaling substances compared with healthy muscle.
- Nearby nerves become sensitized, which is why a trigger point can ache at rest, hurt when pressed, and refer pain to a completely different spot.
Stretching and foam rolling can help the surrounding tissue, but they often can’t break into that locked core. That’s where the needle comes in. If you want the deeper backstory, our post on muscle knots, trigger points, and fascia covers it in detail.
What the Twitch Actually Is
A Reflex, Not a Flinch
When the needle contacts the trigger point, the taut band contracts sharply for a fraction of a second. It looks like the muscle “jumped.” But you didn’t flinch, and the practitioner didn’t cause it by pushing — the twitch is a spinal reflex. The stimulus travels from the trigger point to the spinal cord and straight back to the muscle without involving your brain’s decision-making at all. That’s why you can’t stop it, and also why it’s a reliable sign the needle found the right tissue.
Why Practitioners Look for It
Clinicians trained in dry needling use the twitch as confirmation. No twitch may mean the needle is near the trigger point but not in it, or that the tissue isn’t a true trigger point at all. A clear twitch — sometimes several — tells us we’ve engaged the exact fibers that are causing the problem.
How the Twitch Resets the Muscle
Researchers are still refining the picture, but several mechanisms appear to work together. Think of it as flipping multiple switches at once.
1. Mechanical Disruption of the Locked Fibers
The needle physically disturbs the contracted sarcomeres and the tangled, shortened fibers around them. That sudden contraction-then-release can break the “stuck on” state, allowing the fibers to return toward their normal resting length. It’s a bit like jiggling a jammed drawer — a brief, sharp movement frees what steady pulling couldn’t.
2. Flushing the Chemical Soup
Studies measuring the biochemical environment at trigger points have observed that after a local twitch response, concentrations of pain-related substances in the immediate area drop. The twitch appears to act like a pump — contracting and releasing pushes stagnant fluid out and lets fresh, oxygen-rich blood in. Better blood flow means the energy crisis finally gets resolved.
3. Calming the Nervous System’s Alarm
A chronic trigger point keeps sending “something’s wrong here” signals to the spinal cord, which makes the whole region more sensitive. The stimulation from needling appears to interrupt that pattern — reducing the excitability of the nerve pathways involved and dialing down the muscle’s resting tension. This is likely why patients often feel a broader sense of relief than the size of the needle would suggest.
4. Kick-Starting a Repair Response
The needle creates a tiny, controlled micro-injury. Your body responds the way it responds to any minor tissue disruption: with a brief local inflammatory phase that brings healing cells and signals to the area. That’s part of why the treated muscle feels like it had a workout for a day or so — and why the tissue tends to feel healthier, not just looser, in the days that follow.
Why the Reset Doesn’t Always Stick on Its Own
Here’s the honest part. Dry needling can release a trigger point beautifully, but a trigger point formed for a reason. Maybe a stiff joint made the muscle overwork. Maybe your desk setup keeps the upper traps switched on all day. Maybe a weak glute forces the piriformis to do a job it wasn’t built for. If the reason stays, the trigger point tends to come back.
That’s why, at Lakeside, needling is one piece of a bigger plan. Dr. Allen’s soft-tissue-focused approach pairs the reset with:
- Hands-on soft tissue therapy to restore normal glide between muscle layers and fascia after the trigger point releases
- Joint work when a restricted segment is keeping the muscle in protective spasm
- Simple rehab movements that teach the muscle to hold its new resting length
- Fixing the habit — posture, workstation, training load, or sleep position — that built the knot in the first place
What This Means for You on the Table
Knowing the science changes the experience. That twitch isn’t something going wrong — it’s the moment the treatment is working. The deep ache is the locked fibers being engaged. The next-day soreness is the repair response doing its job. And the looser, quieter muscle you notice a day or two later is what a genuine reset feels like.
Dry needling isn’t right for every muscle problem, and it isn’t magic. But for a true trigger point that’s been driving muscle strain and spasm for weeks or months, it’s one of the most direct tools we have. If you’ve been living with a knot that stretching and massage just can’t reach, that’s exactly the kind of problem it was designed for.
Want to find out whether a trigger point is behind your pain? Call (303) 351-0744 or book a free 30-minute evaluation with Dr. Allen at Lakeside Spine & Injury Center in Wheat Ridge. We’ll find the tissue that’s actually causing the trouble and explain, in plain English, how we’ll reset it.
