A chiropractic adjustment is a hands-on treatment where a chiropractor applies controlled force to a joint, most often in the spine, to restore proper movement. The goal is to correct joints that have become restricted or misaligned, relieving pain and improving function. It’s one of the most common forms of manual therapy in the United States, and the American College of Physicians includes spinal manipulation as a recommended treatment for both acute and chronic low back pain.
What Happens Inside the Joint
Each spinal joint is surrounded by a fluid-filled capsule. When a chiropractor delivers a quick, precise thrust, the pressure inside that capsule drops rapidly, causing dissolved gases to form tiny bubbles in the fluid. Those bubbles collapse almost instantly, producing the popping or cracking sound most people associate with an adjustment. This process is called cavitation, and it’s the same basic physics behind cracking your knuckles.
The pop itself isn’t the point of the treatment, though. The thrust is designed to move a joint that has become stuck or restricted back into its normal range of motion. Some researchers have proposed that the sound actually comes from the elastic recoil of the joint capsule snapping back into place rather than gas bubbles alone. Either way, an adjustment can be effective with or without an audible pop.
Beyond the mechanical effect on the joint, adjustments trigger a neurological response. Sensors embedded in the muscles, ligaments, and joint capsules around the spine detect the sudden change in position and send a burst of signals to the spinal cord and brain. Muscle spindles, which monitor how quickly a muscle is being stretched, fire at high frequency during the thrust and then quiet down afterward, sometimes staying below their baseline activity for 40 seconds or more. This temporary reset in nerve signaling is thought to reduce muscle tension and pain in the area, though researchers are still mapping out the full chain of effects on the central nervous system.
Common Adjustment Techniques
Not every adjustment looks the same. Chiropractors choose from several techniques depending on the patient’s condition, comfort level, and which part of the body needs treatment.
- Diversified technique: The most widely used method. The chiropractor positions you face-down and delivers a quick, firm thrust by hand to the targeted joint. This is what most people picture when they think of a chiropractic adjustment.
- Gonstead technique: Similar to diversified, but you typically lie on your side rather than your stomach. The chiropractor uses very specific body positioning to isolate a single joint.
- Drop table technique: Uses a specially designed table with sections that drop a fraction of an inch at the moment of the thrust. Gravity assists the movement, so less force is needed from the chiropractor.
- Flexion-distraction: A gentler approach where the chiropractor applies light pressure while a segmented table slowly stretches and flexes the spine. There’s no sudden thrust. This is often used for disc-related problems.
- Activator method: Uses a small, spring-loaded handheld instrument to deliver a gentle impulse to the joint. It’s a good option for people who prefer a lighter touch or who are nervous about manual adjustments.
What a Typical Visit Looks Like
Your first visit usually takes longer than follow-ups because the chiropractor needs to assess your condition. Expect questions about your pain, medical history, and daily activities, along with a physical exam that may include checking your range of motion and posture. Some chiropractors take X-rays, though this isn’t always necessary.
The adjustment itself is quick. You’ll lie on a padded table, and the chiropractor will position you for the specific technique they’re using. The thrust takes a fraction of a second. You might hear a pop, feel immediate pressure relief, or notice increased mobility in the area. The entire hands-on portion of a session often takes less than 15 minutes, though some visits include additional therapies like soft tissue work or stretching.
Soreness After an Adjustment
Mild soreness in the hours following an adjustment is common, especially if it’s your first time. Studies show that up to 61% of patients report mild to moderate soreness after their initial treatment. Think of it like the feeling after a workout you haven’t done in a while: the muscles and tissues around the joint are responding to being moved in a new way.
This soreness typically fades within 24 to 48 hours. After a particularly significant adjustment, some people feel it for up to 72 hours. Ice, gentle movement, and staying hydrated can help. The soreness tends to diminish with subsequent visits as your body adapts to treatment.
What the Evidence Says
The strongest evidence for chiropractic adjustments centers on low back pain. The American College of Physicians issued a clinical practice guideline giving spinal manipulation a “strong recommendation” for acute, subacute, and chronic low back pain as a non-drug treatment option. The evidence supporting the recommendation was graded as low-quality, which in clinical research terms means the effect is real but the precision of the estimate could improve with more rigorous studies.
Chiropractors also commonly treat neck pain, certain types of headaches, and joint pain in the extremities. The evidence base for these conditions varies, but spinal manipulation is generally considered a reasonable conservative option before more invasive treatments.
Safety and Risks
Chiropractic adjustments carry a low risk of serious complications. A large retrospective study examining over 960,000 treatment sessions found that severe adverse events occurred at a rate of roughly 0.21 per 100,000 sessions. The two serious events identified in that study were rib fractures, both in women over 60 with osteoporosis. No strokes or spinal cord injuries were recorded.
Broader estimates from multiple studies place the rate of severe complications (fractures, spinal cord compression, or tears in neck arteries) between 1 per 2 million and 7 per 100,000 treatments. The most discussed serious risk involves cervical adjustments, where forceful manipulation of the neck has been linked in rare cases to small tears in the arteries that supply the brain. This risk is higher in people with pre-existing vascular conditions.
Certain conditions raise the risk enough that adjustment is not appropriate. Severe osteoporosis, spinal instability, active infections in the spine, and certain vascular disorders are situations where the forces involved could cause harm. Pregnancy doesn’t rule out chiropractic care, but the approach needs to be modified. A thorough intake process, where you share your full medical history and any medications, helps the chiropractor determine whether treatment is safe for you.
Training and Credentials
Chiropractors in the United States hold a Doctor of Chiropractic (DC) degree, which requires a minimum of 4,200 instructional hours across three and a half to five years of graduate-level education. The curriculum covers anatomy, physiology, radiology, and diagnosis before moving into chiropractic-specific coursework and supervised clinical internships where students treat patients under faculty oversight. After graduation, chiropractors must pass national board exams and obtain a state license to practice.
Insurance and Medicare Coverage
Medicare Part B covers chiropractic adjustments, but only for manual manipulation of the spine to correct what’s called a subluxation, meaning the spinal joints aren’t moving properly even though the bones remain in contact. Medicare does not cover X-rays, exams, or other services a chiropractor may offer. Most private insurance plans include some chiropractic coverage, though the number of covered visits per year and copay amounts vary widely by plan. Checking your specific benefits before starting treatment can save you from unexpected costs.