Possible Clues:

• It causes pain when pulled
• Common injury location
• On rig (anag.)
• Where thighs meet the body
• One place for an athletic pull
• Site of many muscle pulls
• Area between trunk and thigh
• What gets hit by a football in 'Man Getting Hit by Football' in a classic episode of 'The Simpsons'
• It may be pulled by an athlete
• Ringo (anag)