- A randomized controlled trial of hamstring stretching: comparison of four techniquesJo M Fasen
Rehabilitation Institute of Chicago, Chicago, Illinois, USA
J Strength Cond Res 23:660-7. 2009..Improvement in hamstring flexibility was greatest for the SLR passive stretch. Also, using PNF in the 90/90 active stretch provided better knee range-of-motion improvements than the 90/90 passive methods did...