A chiropractic adjustment, formally known as spinal manipulative therapy, is a procedure where a trained practitioner uses their hands or a small instrument to apply a controlled, sudden force to a joint. This specific application of force is intended to restore proper joint motion and improve physical function. Generally, the procedure itself does not cause sharp, acute pain, which is a common concern for people considering an adjustment. While the experience can involve intense pressure or a feeling of momentary discomfort, it is typically not described as painful. The sensation is more accurately characterized as an abrupt, deep pressure followed by a feeling of release.
What You Feel During the Adjustment
The core experience during a chiropractic adjustment is defined by the high-velocity, low-amplitude (HVLA) thrust applied to the joint. This technique involves moving the joint quickly past its typical end-range of motion, but still within its anatomical limits. Patients often report an intense, yet brief, sensation of pressure building up right before the thrust is delivered. This sensation is a direct result of the controlled force being applied to the joint capsule.
The most distinctive part of the adjustment is the audible “pop” or “crack” that frequently occurs, which is scientifically termed cavitation. This sound is not the grinding of bones, but rather the result of gases rapidly escaping the synovial fluid within the joint. When the joint surfaces are quickly separated, the resulting change in pressure causes dissolved gases—such as oxygen, nitrogen, and carbon dioxide—to form a temporary bubble that then collapses, creating the sound.
Many patients describe the immediate post-adjustment feeling as a rush of relief, a sense of lightness, or an increase in mobility. Even when the cavitation sound is loud, the actual physical sensation felt by the patient is usually much less dramatic than the noise suggests.
Patient Factors That Influence Sensation
The immediate sensation during the adjustment can vary significantly based on the patient’s current physical state. One major factor is the presence of acute inflammation in the area being treated, which naturally makes the joint and surrounding tissues hypersensitive to touch and movement. A body part that is already tender due to a recent injury or flare-up may perceive the necessary controlled pressure as more intense discomfort.
High levels of muscle guarding, where muscles tighten involuntarily to protect a perceived injury, can also affect the experience. When chronically tight muscles resist the manipulation, the practitioner’s force may be felt more strongly as the tissues are briefly stretched. Furthermore, a patient’s level of anxiety or expectation can unconsciously influence the perceived sensation. Individuals with high apprehension may interpret the intense pressure and the unexpected sound of cavitation as more jarring or uncomfortable.
The specific technique utilized by the chiropractor can also alter the sensation, with some methods relying on manual force and others using instrument-assisted tools. For instance, a manual high-velocity thrust may create a more sudden, intense pressure, whereas a low-force technique might produce a gentler, less abrupt feeling.
Understanding Soreness After the Visit
It is common to experience a delayed feeling of soreness or mild aching in the hours following an adjustment, which is different from the immediate sensation during the procedure. This discomfort often begins about six to twelve hours after the visit and is frequently compared to the muscle fatigue felt after a moderate workout. This post-adjustment soreness occurs because the body is reacting to the new alignment and the mobilization of previously restricted joints.
The adjustment can stretch muscles and ligaments that were chronically tight, leading to microtrauma similar to what occurs during exercise. This mild inflammation is part of the body’s natural healing process as the muscles adjust to holding the spine in a corrected position.
This delayed discomfort is typically mild and short-lived, usually resolving completely within 12 to 24 hours, though some people may feel it for up to 48 hours. Managing this soreness often involves applying ice or heat to the area, staying well-hydrated, and engaging in gentle movement as recommended by the practitioner.