The present report describes the comparison between a conservative approach and platelet rich plasma (PRP) injections for the treatment of a III grade muscle strain at the proximal femoral bicep junction on two subjects matched for age, sex, trauma, diagnosis, clinical conditions and presentation. The subject treated with PRP was able to walk without pain 1 week after the first injection and was able to start a physiotherapy programme 2 weeks after the injury. On the contrary, the subject conservatively treated was not able to walk without pain 3 months after the injury thus delaying the beginning of the physiotherapy protocol. Seven months after the injury she did not showed a satisfactory recover. In this setting, the early treatment of a muscle strain with the injection of PRP allowed an early mobilization leading to a faster and a more complete recovery.