A groin (adductor muscle) strain is similar to any other type of muscle strain, but it occurs when the muscles of the inner thigh (the adductors) are stretched beyond their limits. This can result in small muscle tears that cause pain and swelling. The groin muscles include the adductor magnus, adductor longus, adductor brevis, pectineus, and gracilis.

The adductors are fan-like muscles in the upper thigh that pull the legs together when they contract. They also help stabilize the hip joint. The adductors attach from the pelvis to the femur (thigh bone).

The most common cause of groin pain is a muscle strain that causes localized pain in the inner thigh, or groin. A severe tear can cause a sudden, acute pain and may be accompanied by swelling and bruising. They are painful to the touch, and pain increases with resistance movements, and stretching of the inner thigh and hamstrings.

These injuries often occur during a sudden change of direction while running and quick starts and stops. These injuries are especially common in field or court sports.
Treating a Groin Pull

For immediate relief, follow the R.I.C.E. treatment plan. Rest, ice, compression and elevation are the best immediate treatment for pulls and strains. Avoid aggravating activities for the first one to two weeks and gradually return to sports. Once activity is started again, ice the muscle after exercise to reduce any swelling. After applying the ice, wrap the thigh to keep it compressed. An anti-inflammatory can be helpful to reduce pain and inflammation for up to a week after the injury.

When inflammation subsides, you can start a stretching program. And then a strengthening program of low-intensity exercises.

Running may be started during recovery, but it should be gentle, gradual and not include hill or sprint work. Pay attention to signs of pain or increased tenderness, and reduce exercise if any develops. Stretch gently and never force a stretch. A return to activity should be possible within two or three weeks.
Preventing a Groin Pull

Proper warm up and stretching is key to injury prevention. Stretching the adductors and hip flexors can also help prevent muscle strains.

Additionally, gradually increasing time, and intensity of activity can prevent overuse and trauma to the working muscles. Muscle strength, and proper biomechanics during activity can also reduce the risk of muscle strains.