Elizabeth comes to the athletic training room complaining of…

Elizabeth comes to the athletic training room complaining of pain in her right quad after track practice. She reports feeling a sharp pain during her leg of the 4×100 relay. She was unable to finish practice because she felt like she could only run at about 60%. Your evaluation reveals the following: 3/5 knee extension 4/5 hip flexion 5/5 knee flexion ++ passive knee flexion tender to palpation over the anterior thigh mild swelling in the anterior thigh Which of the following injuries do you suspect?