After an SI joint injection, the most important thing to do is rest for the first 24 hours. That means no driving, no heavy lifting, and no strenuous exercise. The injection typically contains both a local anesthetic and a steroid, so you’ll likely feel immediate relief that fades within a few hours, followed by a waiting period before the steroid kicks in. Here’s what to expect and how to handle each phase of recovery.
The First 24 Hours
Plan to take it easy for the rest of the day. You should not drive or operate machinery for 24 hours after the procedure. The local anesthetic used during the injection can temporarily affect sensation and muscle control in your lower body, making it unsafe to be behind the wheel. Arrange a ride home before your appointment.
For the injection site itself, you can remove the bandage after about 12 hours. Once the bandage is off, showering is fine. However, avoid submerging the area in water for 24 hours, so skip baths, hot tubs, and swimming pools during that window. This reduces the risk of introducing bacteria to the injection site while it’s still healing.
If the area feels sore, apply an ice pack wrapped in one or two layers of towel for 15 to 20 minutes at a time. You can repeat this several times throughout the day. Avoid using heat on the injection site during this initial period, as heat can worsen inflammation from the needle puncture itself.
Post-Injection Pain Flare
About 1 in 5 people experience a temporary increase in pain after a corticosteroid injection. This “steroid flare” happens because the crystalline structure of the medication can irritate the joint before it starts working. In studies of joint injections, roughly 20 to 35% of patients reported this flare, with symptoms lasting an average of about 4 days. The flare typically peaks within the first day or two and then gradually subsides.
If your pain gets worse before it gets better, that’s not necessarily a sign something went wrong. Ice and over-the-counter pain relievers can help you manage the discomfort during this phase. However, if you develop a fever, notice increasing redness or swelling spreading outward from the injection site, or experience new weakness or numbness in your legs, contact your provider. These could signal an infection or a rare complication that needs attention.
When Pain Relief Begins
The local anesthetic injected alongside the steroid often provides immediate relief that lasts a few hours. Once it wears off, you may feel like the injection didn’t work. This is normal. The steroid component takes time to reduce inflammation.
In a prospective study tracking patients after corticosteroid injections, 50% experienced meaningful pain relief within 3 days, and about 94% had improvement within a week. People who experienced a post-injection flare took about 1.5 days longer on average to notice improvement (roughly 4.5 days compared to 3 days for those without a flare). So give the injection at least a full week before judging whether it helped.
Returning to Exercise and Daily Activities
The general recommendation is 1 to 2 days of rest for the injected area, followed by a gradual return to activity. The first 24 hours should be relative rest to allow the medication to absorb properly. After 24 to 48 hours, you can begin light, progressive activities like riding a stationary bike, using an elliptical, or doing bodyweight exercises. From there, increase intensity as your symptoms allow.
This isn’t the time to test your limits. Jumping straight into heavy deadlifts or a long run on day two can stress the joint before the steroid has fully taken effect. A better approach is to use the first few days for gentle movement, then ramp up over the course of a week as the pain relief builds. If an activity causes a noticeable increase in SI joint pain, back off and try again in another day or two.
Starting or Resuming Physical Therapy
One of the main benefits of an SI joint injection is that it creates a window of reduced pain, making it easier to do the strengthening and stabilization work that addresses the root cause of SI joint dysfunction. Many providers recommend beginning or resuming physical therapy once the steroid takes effect, typically 3 to 7 days after the injection.
Physical therapy for SI joint problems usually focuses on strengthening the muscles around the pelvis, including the glutes, deep core stabilizers, and hip rotators. These muscles help hold the SI joint in proper alignment during movement. The injection alone provides temporary relief, often lasting weeks to a few months. The exercises you do during that pain-free window are what build the long-term stability that can keep pain from returning.
Tracking Your Response
Your provider will likely ask you to keep a pain diary or at least mentally note how your symptoms change over the first week or two. This matters for two reasons. First, if the injection significantly reduces your pain, it confirms that the SI joint is actually the source of your problem. SI joint injections serve a diagnostic purpose as well as a therapeutic one. Second, tracking your response helps guide next steps, whether that’s repeating the injection, adjusting physical therapy, or considering other options.
Pay attention to how much relief you get and how long it lasts. Some people experience weeks or months of improvement from a single injection. Others find the relief shorter-lived, which may prompt a different treatment approach. Either outcome gives your provider useful information for managing your care going forward.