If you hyperextended a muscle, you should follow the RICE method: Rest, Ice, Compression, and Elevation. Rest the affected muscle and avoid activities that cause pain. Apply ice to the affected area for 20-30 minutes every 3-4 hours to reduce swelling and pain. Use a compression bandage to help reduce swelling, but make sure it's not too tight. Elevate the affected area above the level of your heart to help reduce swelling. If the pain and swelling persist or worsen, seek medical attention.