Hamstring
Ischial Tuberosity Apophyseal Avulsion

A Ischial Tuberosity Apophyseal Avulsion is an injury where the hamstring muscles pull a piece of bone away from the "sit bone" (the bony bump at the bottom of the peelvis that you sit on, called the ischial tuberosity). This happens at the growth plate, a soft area of developing cartilage near the end of a bone where growth occurs in young people. Because the growth plate is the weakest link in the chain of muscle-tendon-bone, it gives away before the muscle or tendon does. This injury only happens in teenagers whose bones are still growing, around the ages of 10-18.

  • Sudden, sharp pain in the buttock or back of the hip during forceful movement (sptinting, kicking, jumping)
  • A possible "pop" or snapping sensation at the moment of the injury
  • Difficulty walking such as limping of inability to put full weight on the injured leg
  • Tenderness when pressing on the "sit bone"
  • Pain bwhen bending the knee against resistance (i.e. trying to pull your heel toward your buttock while someone resists)
  • Pain when stretching the hamstring
  • Bruising of the back of the thigh
  • Pain that may radiate down the back of the thigh, sometimes mimicjing sciatic neve pain
  • Pain when sitting on hard surfaces
  • Occurs during a sudden, explosive movement in which a "pop" is heard, followed immediately by a sudden, sharp, shooting pain.
  • Pain is severe enough that you have to stop any activity.
  • The pain occurs in the deep buttocks on the "sit bone" (the bony bump you can feel when you sit on a hard surface)
  • Pain typically radiates down the back of the thigh, making walking difficult and sitting painful
  • Sprinting or accelerating suddenly
  • Kicking forcefully
  • Jumping or hurdling - explosive takeoff movements
  • Sliding into a split and forced overstretching of the hamstrings
  • Rapid deceleration (i.e. suddenly slowing down frmo a sprint)
  • Lifting heavy weights with poor form
  • Am I between the ages of 10 and 18?
  • Did the pain start suddenly during a specific movement, rather than building up gradually over time?
  • Did I feel or hear a "pop" in my buttock area at the moment of injury?
  • Is the pain located deep in the buttock, right on the "sit bone", rather than in the middle of the back of the thigh?
  • Is it painful to sit on hard surfaces?
  • Am I having significant difficulty walking?
  • Does it hurt when I try to bend your knee against resistance?
  • Has the pain persisted or worsened despite rest and typical hamstring strain treatment?
  • Was I in a growth spurt around the time of injury?

Educational only — not a medical diagnosis.

  1. 1Stop the activity immediately.
  2. 2Apply ice to the buttock area for 15–20 minutes at a time, with a cloth barrier to protect the skin. Repeat every 1–2 hours in the first 24–48 hours.
  3. 3Use crutches and avoid putting full weight on the injured leg until evaluated by a medical professional.
  4. 4Do not stretch the hamstring. Unlike a simple muscle pull, stretching can pull the bone fragment further away and make the injury worse.
  5. 5See a doctor and get X-rays.
  6. 6Do not return to sports until cleared by a medical professional.
  • Numbness, tingling, or shooting pain down the back of the leg.
  • Inability to walk at all or severe pain with any weight bearing.
  • Significant swelling or rapidly spreading bruising in the buttock or thigh.
  • Pain that gets worse over days rather than gradually improving.
  • Loss of strength and inability to bend the knee or extend the hip against even light resistance
  • Symptoms that persist beyond 2–3 weeks despite rest.
  • A hard lump developing in the buttock area weeks after the injury.
  • Do not rush back to sports. Returning too early is the most common reason for complications, including nonunion (the bone never reattaching). The reinjury/complication risk is highest in the first few months.
  • Avoid sitting on hard surfaces for prolonged periods during recovery.
  • Maintain fitness safely withupper body exercises and swimming (if pain-free) can help maintain conditioning without stressing the injury.
  • Watch for warning signs during recovery. If pain plateaus or worsens after initial improvement, return to the doctor for repeat imaging to check healing progress.
  • Follow a phased rehabilitation program.

For educational purposes only. Not a substitute for medical advice.

Tracks symptoms over time (not a diagnosis).