Dry needling (DN) is a therapeutic technique that uses thin, sterile needles to address myofascial trigger points—localized, hyperirritable spots within a taut band of muscle. The goal of this minimally invasive procedure is to release muscle tension, improve blood flow, and relieve pain and movement restrictions. While the idea of needles raises concerns about pain, the sensation experienced is generally a manageable discomfort that signals a therapeutic response.
The Difference Between Acute Pain and Therapeutic Sensation
Dry needling is typically not associated with the sharp, acute pain felt with a hypodermic injection, because the needles used are ultra-thin and solid, not hollow. The initial insertion through the skin may feel like a quick, mild prick, but often the patient does not feel it at all. The primary and desired sensation occurs when the needle reaches the myofascial trigger point deep within the muscle tissue.
This specific sensation is known as the “local twitch response” and is a key indicator of treatment effectiveness. The local twitch response is an involuntary, spinal cord reflex that causes the muscle fibers to contract briefly and then quickly release. Patients often describe this momentary feeling as a deep ache, a quick cramp, or a sensation similar to a brief muscle spasm or a mild electric shock.
The discomfort from this twitch is purposeful, as it is the physiological mechanism that deactivates the trigger point. When the needle causes this reflex, it helps to break the tight band of muscle fibers, which reduces the concentration of pain-causing biochemicals in the area. This therapeutic discomfort is short-lived, usually lasting less than a second, and signals that the treatment is successfully restoring the muscle to a more relaxed state.
Factors That Influence the Level of Discomfort
The intensity of the dry needling sensation can vary significantly based on several factors, including the characteristics of the muscle being treated. Muscles that are highly active or contain very taut and sensitive trigger points are more likely to elicit a stronger local twitch response. Areas with a high degree of muscle dysfunction may feel more intense discomfort during the procedure.
The location of the muscle also plays a role in the sensation experienced during treatment. Needling a large, deep muscle, such as the gluteal muscles or thigh muscles, may cause a deeper, more profound cramping sensation compared to a smaller, more superficial muscle like one in the forearm. The depth and size of the needle chosen by the practitioner are also contributing factors, as a longer needle is required to reach deeper muscle structures.
The skill and technique of the practitioner greatly influence the patient’s comfort level. An experienced, well-trained therapist can effectively locate the trigger point and perform the technique with precision, which minimizes unnecessary discomfort. Furthermore, a patient’s individual tolerance for pain and their overall nervous system sensitivity to physical stimuli can affect how they perceive the treatment.
What to Expect Immediately After the Procedure
Once the needles are removed, the immediate post-procedure sensation shifts from the twitch response to a feeling of post-treatment muscle response. It is common to experience mild soreness or tenderness in the treated area, which is often likened to the feeling of having completed a strenuous workout or experiencing Delayed Onset Muscle Soreness (DOMS).
Some patients also report feeling general fatigue or a heavy sensation in the body. This temporary tiredness is a normal reaction to the physical and neurological stimulation triggered by the treatment. The soreness and fatigue are typically mild and temporary, generally subsiding within 12 to 48 hours as the muscle tissue adapts to its new, more relaxed state.
Minor side effects at the insertion site are also possible, including slight redness or the appearance of a small bruise. Bruising occurs because the fine needle can sometimes break a small capillary, but this is harmless and fades within a few days. Staying hydrated and avoiding intense physical activity immediately following the session can help manage this temporary post-treatment soreness and support the muscle’s recovery.