Symptoms of a strain vary depending on the location and severity of your injury. Common signs of a strain include muscle spasms, sudden pain, soreness, swelling, and limited range of motion. With mild strains, you may feel only slightly stiff or uncomfortable. With a severe strain, you can experience extreme pain. All sprains, however, generally cause pain right away and are sometimes correlated to a change in activity. In other cases, the pain may occur randomly. Your skin or the affected area might also feel tender to the touch.