How Does Dry Needling Work?
Trigger point dry needling is becoming an increasingly popular treatment method utilized by physical therapists to treat muscle pain. If you have been a patient at Outlast, you may have already encountered dry needling. As a PT that utilizes dry needling on a daily basis, I often get asked “how does this work?” My standard answer is usually a variation of “It creates a local twitch response in your muscle which helps relieve the tight tissue and improve blood flow to the area”. However, it is much more complex and really interesting. If you want a mini deep dive on dry needling, keep reading!
To understand how dry needling works to alleviate trigger points, it is important to understand how trigger points form in the first place. A trigger point is defined as “a hyper-irritable band of fascia along a skeletal muscle”. These hyper-irritable bands cause a local muscle contractacture (or seizing) of the muscle and connective tissue which prevents localized blood flow to the area. They can form in response to injury, chronic low level contractions (such as sitting with bad posture), lack of exercise, chronic overuse, chronic stress conditions, or chronic joint conditions. Let me be clear, they are VERY common. We all have trigger points. Even children and animals can have trigger points. Sitting here typing this blog post I can feel a trigger point in my upper traps. However, they don’t always develop into a pain condition. This is the difference between active and latent trigger points. Active trigger points are painful to the touch, painful to stretch, painful to load, and can cause referred symptoms into surrounding areas. Latent trigger points are still tight bands of fascia, but they have not crossed the threshold into an active trigger point to the point where they are limiting muscle function and causing pain. In case you are concerned about my knot in my upper traps, don’t worry, it is a latent trigger point and I am okay. In physical therapy, we are most concerned with treating active trigger points.
Now this may sound obvious, but dry needling only uses the stimulation of a solid needle to relieve trigger points. This is different from wet needling that usually contains a steroid medication that is injected into the muscle. The dry needle is inserted into the trigger point and often the patient will feel a localized twitch. This twitch is thought to be a spinal cord reflex linked to the sensitivity of the area being stimulated. In essence, it is not something that can be controlled by the patient. It is an involuntary response of the nervous system. The localized twitch response is a very important part of the pain relieving process because it stimulates a change in the extracellular matrix. The extracellular matrix is the supportive connective tissue within the muscle that is made up of proteins, sugars, and other components. The twitch activates fibroblasts which then synthesize pain-relieving chemicals and helps to re-balance the concentration of the extracellular matrix to an environment that stimulates healing. The collagen fibers of the fascia are also able to re-align during this process and the constriction that was once on the local blood vessels is released, restoring improved localized blood flow which helps muscles relax and function properly again.
You will notice that your PT will insert the needle and without fully removing it, he or she may then adjust the angle of the needle and insert again. This is to stimulate multiple twitch responses within the same area of muscle contraction thus leading to more improved blood flow and relaxation of the stimulated muscle. The entire experience of dry needling should only last seconds per needle. You may notice that the muscles that were needled can be sore for a few hours after the needling and this is because local inflammatory chemicals have been released and your cells are undergoing the process of removing harmful material and restoring the tissue. So just like our cells go through a break-down and rebuilding process with strength training, our tissues will have a delayed soreness during this process. It is totally normal and you can go about your regular day. Typically subsequent needling sessions, especially to the same area will not be as sore post-needling as the first session.
It is important to note that dry needling is only one small component of relieving muscle pain long-term. If you only do dry needling but then you do not address the underlying muscle imbalance, postural issue, overuse, training errors, etc. that lead to the trigger points in the first place, you may find yourself in a horrible revolving door scenario. That is why it is important to have a well rounded treatment plan when dealing with muscle pain that identifies and addresses the root cause.
If you are curious to read more about the science behind dry needling, refer to the below sources.
Shannon Hall, PT, DPT
https://www.physio-pedia.com/Trigger_Points
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6590623/