To reduce the occurrence of accidents during the train-to-train collision test. it is necessary to carry out research on derailment protection. According to the characteristics of the train-to-train collision test. a method of using a U-steel as a guard rail is proposed. https://eqylxwrgajz1.wikicorrespondence.com/4843723/the_use_of_msk_ultrasound_with_quadriceps_muscle_injury