A group of researchers at University Hospital of Parma in Italy collaborated to demonstrate potential benefit of PRP application to muscle strains.

Drs. Gernuzzi, Petraglia, Pedrini, De Fillipo, Pogliacomi, Verdano, and Constantino have recruited a total of 53 patients who had an acute muscle tear of various muscles in their university emergency room. Patients recruited were all recreational athletes in different sports such as volleyball, soccer, basketball, and dancing.

Ultrasound was used to grade the tear, and only grade II (moderate) tear was recruited for the study and they all received PRP injections under ultrasound guidance for a total of 3 times, one week apart of each other. The study demonstrated these patients treated with PRP demonstrated clinically meaningful improvement in pain scale (as measured by visual analogue scale of pain), improvement in visual characteristic on ultrasound, and 100% of patients returned to their regular sporting activity within 30 days of the last injection. Only one patient experienced a relapse of the injury by one year follow up.

This study was unique in that it looked at the efficacy of PRP application to acute muscle injuries whereas most PRP studies have investigated its application to chronic tendinous / ligamentous injuries or cartilage lesions.
Time to improvement in this study was also unique. Most chronic tendinous injuries have been reported to have much slower response to PRP (weeks to months), this study has suggested muscular application of PRP may result in faster resolution of pain and recovery of function.

While this study suggested safety and potential benefit to PRP application to acute, moderate muscle tears, further study is warranted to compare PRP with conventional conservative treatment (a design known as a randomized control trial), and also, future studies should investigate the effect of PRP per different muscle types.

View Abstract: http://www.ncbi.nlm.nih.gov/pubmed/23867186