Groin pain, like hamstring pain, can often be the result of the muscles having to work too hard because of inadequate strength or flexibility in other muscles around the pelvis. Your groin muscles consist of 4 main muscles. The Adductor Longus, Brevis and Magnus and your Pectineus. and each one is activated and work more strongly as hip is passes through different positions.
Your adductor magnus is the largest of the adductor muscles and is a common causes of posterior thigh pain and people often complain of hamstring pain when this muscle is invoved.
Another reasons for pain or discomfort high up at the front of your groin can be a restriction in your hip capsule. To see if you have a tightness in your capsule, lie on your back and bring your knee up towards your chest. If this movement is restricted or if you feel a pinch deep in your groin then it could be because of a restriction in your hip capsule or excessive tone in your Adductor Magnus.
Groin pain often results when there has been an imbalance in your hip muscles for some time and because of this can often take a little bit longer to rehabilitate.