For example, if your knee tends to hurt during or after a run or walk, your IT band might be responsible. When your IT band is overworked or tight , it literally rubs on your femur and gets inflamed, which causes pain on the outside of your knee. This is commonly referred to as "IT band syndrome," McLaughlin says, and it's the most common running injury (up to 12% of runners have it). A tight IT band can also contribute to bursitis in your hip, which is another running injury, McLaughlin says. Part of the IT band's job is to keep your knee in line as you move, so if you have a wonky gait (like you run with your feet slightly turned out or you pronate) or tend to do workouts that require a lot of leg stability (like dance or soccer), that can make your IT band tight and inflamed , too.