Epidemiology: Occurs in gymnasts with open growth plates, meaning they are still growing and have not yet finished going through puberty.
Mechanism of Injury/Description: This occurs from repetitive stress and traction/pulling from the hamstring muscle on the growth plate at the ischial tuberosity (“butt bone”) causing injury, and either inflammation (apophysitis) or a fracture (avulsion). Avulsion refers to the muscle forcefully being pulled and taking a piece of bone with it causing a fracture.
Signs/Symptoms: The gymnast will complain of pain on the “butt bone.” If this is an avulsion injury the gymnast will experience a “pop” or “snap” followed by immediate pain, bruising down the leg, and inability to ambulate (walk) normally. In the case of an apophysitis injury, there will be pain with activation/using the hamstring muscles and swelling.
Diagnosis: Diagnosis is determined by physical exam when there is pain to palpate/push on ischial tuberosity. An x-ray can also determine the diagnosis. An AP supine pelvis x-ray may show widening at the growth plate (apophysitis) or an avulsion fracture (the bone has “pulled off” at the attachment of the muscle/growth plate). MRI or CT would be the definitive test to give the diagnosis.
Treatment: The gymnast should rest from all jumping/pounding/impact. Potentially the gymnast may be prescribed crutches, NSAIDs, physical therapy, and possibly surgery (if there is an avulsion fracture, displacement >3cm).
Prevention: To prevent this injury consider proper stretching of the lower extremity, focusing on safe landing mechanics, core strength, and gluteus/hip strength and listening to your body and telling an adult if you are experiencing pain.
Gymnastics Medical Provider PEARLS: This can be a very challenging diagnosis as almost every skill/event in gymnastics involves use of the hamstring (Ex: kicks, jumps, kips, tap swings, back handspring, running, etc…) and so for the first 2-6 weeks from the diagnosis gymnastics is very limited (gymnasts could do conditioning-upper body and core if given clearance by a medical provider). There have been some gymnasts who try to do uneven bars during this rest period but those who do tend to have a longer recovery as they really aren’t “resting” the hamstring completely.
Gymnast, Parent, and Coach PEARLS: If your gymnast has pain in her/his buttocks/hamstring region do not ignore this! See a medical provider as soon as you can. Focus on splits with square hips and proper stretching to avoid this.