How Dry Needling Works: Trigger Points, Pain Sensitization & Scar Tissue

Dry needling is more than just poking a muscle—it's a targeted, evidence-informed technique that leverages the body’s own healing mechanisms. As physical therapists, we use dry needling to address a wide range of neuromuscular dysfunctions. While many patients feel the benefits, few truly understand what’s happening beneath the skin. In this post, we’ll break down three primary mechanisms of dry needling: trigger point release, pain desensitization, and scar tissue remodeling.

Goals of Dry needling

1. Releasing a Trigger Point

A trigger point is a taut band or "knot" in skeletal muscle, often palpable and painful on compression. It may restrict movement, alter biomechanics, and refer pain to distant areas. When a needle is inserted into a trigger point, a few key physiological events occur:

• The needle disrupts the dysfunctional motor endplate at the neuromuscular junction, interrupting abnormal acetylcholine release.

• It can provoke a local twitch response (LTR)—a spinal cord reflex that leads to a rapid contraction and relaxation of the taut band.

• This reset can normalize chemical imbalances (like pH, inflammatory cytokines, and neurotransmitters) in the area, allowing the muscle to return to a relaxed, functional state.

In short: The needle acts like a reboot button, restoring normal tone and allowing more effective movement and strength.

2. Decreasing Pain via Central Desensitization

Chronic pain isn’t just about tissue—it’s also about the nervous system. In some patients, their nervous system becomes hypersensitive, reacting too strongly to normal stimuli. This is known as central sensitization.

What is Central Sensitization?

Central sensitization is when the central nervous system (brain and spinal cord) becomes overreactive to a painful input. Patients may feel pain from light touch, mild pressure, or even without any stimulus at all. This altered pain processing is common in chronic conditions like fibromyalgia, tendinopathies, and post-surgical pain.

How Dry Needling Helps:

• Needle insertion stimulates A-delta and C fibers, sending strong sensory input to the spinal cord.

• This input disrupts the "noise" of chronic pain signals and helps normalize pain thresholds.

• Dry needling can also trigger descending inhibitory pathways, which are the body’s natural painkillers, reducing hypersensitivity in both the needled area and nearby tissues.

Over time, this neuromodulation may help retrain the nervous system to stop overreacting to non-threatening stimuli—essential for patients with chronic, widespread, or centrally mediated pain.

3. Releasing Scar Tissue and Fascial Restrictions

Dry needling is also an emerging tool for soft tissue and scar remodeling—especially when combined with fascial techniques.

When a needle is inserted into dense, fibrotic tissue (like a post-surgical scar or old injury site), it initiates a mechanical and cellular response:

• The needle mechanically disrupts adhesions between layers of fascia and muscle.

• In some techniques (like fascial needling), the needle is rotated or "wound", creating tension in the extracellular matrix.

• This “winding” process aligns and stretches collagen fibers, triggering fibroblast activity and promoting tissue remodeling.

Over time, this can help:

• Reduce tissue density and stiffness,

• Improve range of motion, and

• Restore interfascial glide that’s essential for smooth, pain-free movement.
  
  
  

Common Dry Needling Techniques

1. Pistoning (Trigger Point Style)

This is the most traditional and commonly recognized dry needling approach. The clinician uses a single needle, rapidly inserting and withdrawing it multiple times within a target muscle—especially into a palpable trigger point.

• The goal is to elicit local twitch responses (LTRs).

• The pistoning motion disrupts the trigger point and normalizes muscle tone.

• This technique is brief, targeted, and usually done with manual palpation guidance.

2. Scar or Fascial “Winding”

This method is particularly effective for scar tissue, fascial restrictions, and chronic soft tissue injuries.

• The needle is inserted into the tissue and then gently rotated or twisted (“wound up”) while remaining stationary.

• This creates mechanical tension that helps align collagen fibers and mobilize fascial planes.

• Over time, this promotes tissue remodeling and improved glide between layers of soft tissue.

This method is slower and more deliberate than pistoning and often used in dense or fibrotic areas like post-surgical scars, tendinous insertions, or chronic myofascial adhesions.

3. Static Needling with Electrical Stimulation (E-stim)

In this technique, needles are inserted and left in place, often for 10–20 minutes. Some or all needles are connected to a low-frequency electrical stimulation unit.

• The stim pulses cause rhythmic muscle contractions or gentle fasciculation.

• E-stim enhances blood flow, promotes endogenous opioid release, and accelerates tissue healing.

• It’s particularly effective for neuromuscular reeducation, chronic pain, and post-operative recovery.

This method is well tolerated and can be calming, especially when used with lower frequencies (1–4 Hz) for analgesia or higher frequencies (20+ Hz) for neuromotor stimulation.

Conclusion: One Tool, Many Effects

Dry needling isn't a one-trick modality. It’s a versatile intervention that:

• Calms overactive muscles (trigger point relief)

• Tones down an overactive nervous system (desensitization)

• And breaks up stubborn scar tissue (fascial remodeling).

Understanding how and why it works allows us to apply it more effectively—and explain it more clearly to our patients. Whether you're treating a post-op shoulder, chronic low back pain, or neural tension after an ankle sprain, dry needling can be a powerful addition to your clinical toolbox.

Disclaimer:
This blog post is intended for general informational purposes only and should not be taken as medical advice, diagnosis, or treatment. It is not a substitute for a consultation with a licensed healthcare provider or physical therapist. Additionally, this content is not intended to serve as clinical training or educational material for therapists. Clinicians should always rely on their accredited continuing education courses, scope of practice, and professional judgment when performing any intervention, including dry needling. Reading this post does not establish a patient-provider or professional mentoring relationship with Local Point Physical Therapy or Dr. Christine Kornegay, DPT.