The inner thigh muscle is also called the adductor muscle, and it is primarily responsible for turning the toe in while walking or running. It is possible to pull or injure the upper inner thigh or the lower inner thigh while performing different exercises or to simply overwork the muscle by running, hiking or playing sports past the point of fatigue or tensing the muscle to avoid slipping while running or walking on wet surfaces.
One of several causes of inner thigh pain may be due to a groin strain or a groin pull. This often happens to runners and those who play sports -- such as soccer or tennis -- that involve a great deal of running. The inner thigh pain can be mild, caused by a small strain of muscles that connect the thigh bone to the pubic bone. Inner thigh pain can also be moderate to severe, caused by a total rupture of those same muscles. Additionally, you may experience pain on the outside of the inner thigh due to rash caused by the friction of the thighs rubbing together while running on a treadmill or outside.
One of the best ways to avoid inner thigh pain from exercise is to completely warm up the muscles before running or playing sports that involve a high amount of running. Next, avoid overtraining as this can overwork the muscle and cause pain or injury. Supportive shoes also help, as does stretching thoroughly after a workout.
If you experience pain in your inner thigh, your first step should be to rest the leg and avoid running and other exercises that stress the muscle until the pain subsides. If there is slight swelling or if the pain is caused by a rash, apply ice to cool the area to limit the pain and call the doctor to see if the issue is serious enough to come in.
According to the U.S. National Library of Medicine's MedlinePlus, you should call your doctor if your leg is swollen or red, if you have a fever in addition to thigh pain, your pain gets worse when you walk or exercise but gets better when you rest, if you have bruises, or if your leg is cold and pale. You should also contact your doctor if the home remedies to reduce pain do not work for you.