An ischial apophysis avulsion is an injury to the sitting bone where the hamstring muscle meets the bony protrusion of the sitting bone or ischial tuberosity. An avulsion is an injury in which movement or injury results in a violent and sudden contraction of the hamstring which pulls a piece of the sitting bone with it. This injury typically affects young athletes, aged 13 to 25 years. Symptoms include ischial tuberosity pain, swelling and pain in the thigh area, muscle spasms, and muscle weakness in the legs. To heal the injury, extended rest and massage are typically in order as well as stretching exercises and gait work.
Note: Exercises that strengthen the hip flexors also involve contracting (shortening) these muscles. So if tight hip flexors are a problem for you, it might be wise to limit how many direct hip-strengthening exercises you perform. These exercises are more geared toward people who have been told they have weak hip flexors that need strengthening or are looking for targeted exercises to build more power and stamina in the hip flexors.
Grade II (moderate): A larger tear in your muscle that makes it difficult to move and causes a moderate amount of pain, especially when you move the affected muscle, swelling, and tenderness. You may have 5 percent to 50 percent loss of function and you may be limping. You can't go back to sporting activities until the tear is completely healed. These injuries can take anywhere from a couple weeks to a few months to heal, depending on how bad they are.