Copyright, The American Running Association.
A groin pull is the tearing of the hip adductor, or inner thigh muscles. The inner thigh muscles are used quite frequently for propelling you straight ahead or from side to side. They're even responsible for allowing you to move your foot inward.
As with any muscle pull, its severity is rated as a Grade I or II, which means a slight to moderate tear, or a Grade III, which is a complete rupture. As with any muscle pull, it takes persistence and dedication on your part to heal a groin pull.
Signs and Symptoms:
You'll often feel a sharp pain when the injury occurs, which forces you to stop exercising. When you try to start again, pain again forces you to stop. The pain can stay in one area, or may extend down the inside of the thigh. Often, bruising develops hours later that starts at the groin and moves down the inner thigh. If this happens, don't worry that the injury is spreading. Gravity is forcing the blood down and making the injury appear more widespread than it is.
Therefore, pain is usually worsened by running with changes in direction (cutting), running in a straight line if the foot is turned in or out, getting in and out of cars, climbing stairs, or simply walking.
Causes:
Overuse. You could over use the inner thigh muscles in obvious ways.
Foot imbalance. Certain foot imbalances force you to constantly use your adductor muscles, which leads to overuse of the muscles.
Improper conditioning. If you're not adequately prepared for an activity, you run the risk of pulling your groin muscles. These muscles should be properly strengthened and stretched.
RX Measures:
Stop exercising immediately.
Ice for 10 minutes, then remove the ice for 10 minutes. Do this periodically throughout the day.
Take anti-inflammatories. This will help to keep the swelling down.
Don't exercise again for at least seven days. When you start again, stop if pain develops.
Compression. Wrapping the area with elastic wrap can provide comfort.
Stretch and strengthen. As the pain subsides after a few days, begin light stretching and strengthening exercises. Squeezing a small ball between your knees, for instance, is a simple effective exercise. Don't do any exercises that cause pain. As you begin to resume activity, try heating the area before exercise. (Continue to use ice after exercise.)
Rehabilitation exercises. Once your groin starts healing, it's imperative to continue rehabilitation exercises to keep the area strong and flexible. The muscles have a tendency to shorten after injury so it's important to keep them stretched. Generally, running in a straight line or bicycling are good alternatives. However, pain is the best guide.