Establishing weighted criteria for return to play after hamstring injury: a systematic review and methodological quality analysis

INTRODUCTION: Hamstring injuries are the most prevalent in active individuals aged between 20 and 70 years, with a high recurrence rate of 57% during the first month. The lack of a clear consensus on the return to activity of these patients could lead to an increase in the incidence of relapses, as well as greater economic costs. METHODS: A systematic review was carried out, following the PRISMA guidelines. The article search was conducted in the PubMed, Sportdiscuss, WOS and Scielo databases, using the terms "hamstring muscle" OR "biceps femoris" OR "semimembranosus" OR "semitendinosus" OR "hamstring tendon" OR "semitendinosus tendon" OR "semimembranosus tendon" OR "biceps femoris tendon" AND "return to sport" OR "return to play" OR "resumption of sporting activities" OR "return to sporting activities" OR "recreational activities resumption" OR "return to recreational activities". RESULTS: 22 studies were finally included in the present review. The main variables analyzed were the presence of pain, the performance of functional tests, the measurement of flexibility and range of motion, the strength developed and the use of imaging tests. CONCLUSION: Pain measurement has been shown to be the most common criterion for determining return to activity, and its combination with other complementary measurements such as strength, flexibility and the ability to perform sport-specific movements at maximum speed is recommended.