There is a new trend going viral on TikTok where people have been filming themselves swinging their arms in a circle, windmill-style, after receiving their shot, in hopes it will prevent or limit arm pain after the vaccine. But does it work? Peter Chin-Hong, MD, an infectious disease specialist and professor of medicine, told the San Francisco Chronicle that it is, in fact, likely to ease arm pain. “Basically, what they’re doing… is increasing the blood supply to the arm that’s vaccinated,” he explained. According to Chin-Hong, your arm becomes sore because the vaccine is injected into your arm muscle and not the bloodstream, which causes your immune system to target inflammation at the muscle area. But moving your arm in a circle can help increase your arm’s blood flow, which will diffuse the vaccine away from your muscle and let the immune system begin to target other parts of your body. And for more on what to do after vaccination, Make Sure to Do This the Day After Your COVID Vaccine, Experts Say. There is no guarantee that you will stop all arm pain from occurring by swinging your arm. But doing so consistently and immediately after your vaccination is likely to reduce some pain, according to Chin-Hong. He told the San Francisco Chronicle that moving your arm as soon as you’re released from your vaccine waiting period is important in order to help disperse the vaccine sooner, which is more likely to reduce soreness than waiting to do arm exercises when you get home. Allison Agwu, MD, an infectious diseases specialist at Johns Hopkins Medicine, also told Today that when you get the COVID shot—or any other vaccine—you should always “try to move your arm” as much as possible. “Staying still will just increase muscle soreness,” she says, noting that restricting your movement causes the vaccine to stay concentrated in one spot for longer, which can lead to discomfort. And for more up-to-date COVID vaccine news delivered right to your inbox, sign up for our daily newsletter. You may think massaging your arm will produce similar results without the need for exercise, but not quite. Chin-Hong said massaging your arm isn’t likely to yield the same effect as swinging it around in a circle. “If you massage the area it probably isn’t going to be as good as moving your arm like a windmill because it’s just making the vaccine just stay in the muscle area so it’s not increasing blood supply,” he explained.ae0fcc31ae342fd3a1346ebb1f342fcb That’s why the CDC recommends exercising your arm to reduce pain and discomfort after the shot or applying a clean, cool, wet washcloth over the area, which Chin-Hong said can help as well. And for more on what you shouldn’t do after the vaccine, Don’t Do This for 2 Days After Your COVID Vaccine, Doctors Say. Arm pain or tenderness is one of the most common side effects that can occur after your COVID vaccination, according to the CDC. But it should go away in a few days. If redness or tenderness where you got your shot gets worse after 24 hours, the CDC recommends that you contact your doctor or healthcare provider. And if your side effects are “worrying you or do not seem to be going away after a few days,” then you should also reach out, per the CDC. And for more on what they advise, find out why The CDC Says Don’t Take This After Your Vaccine Without a Doctor’s OK.