Grade III (severe): A complete tear in your muscle that causes severe pain and swelling and you can't bear weight on that leg, making it difficult to walk. You've also lost more than 50 percent of your muscle function. These injuries are less common and may need surgery to repair the torn muscle. They can take several months or more to completely heal.
The main work of your hip flexors is to bring your knee toward your chest and to bend at the waist. Symptoms associated with a hip flexor strain can range from mild to severe and can impact your mobility. If you don’t rest and seek treatment, your hip flexor strain symptoms could get worse. But there are many at-home activities and remedies that can help reduce hip flexor strain symptoms.