Comparative Study of Different Stretching Protocols on Flexibility and Passive Resistance of Hamstrings

This investigation determined the effects of different static stretching protocols on flexibility and passive resistance of the hamstrings. Forty healthy young adults were randomly assigned into one of four groups. The two training groups underwent static stretch training by a four-week and an eight-week protocol, respectively. The other two were control groups. A significant increase in hamstring flexibility was found in both of the two training groups. No difference was found in the amount of range of motion (ROM) gained between the two training groups. An increase in passive resistance was only found in the four-week training group. Both protocols are effective in terms of improving hamstring flexibility. However, if injury is reduced when there is relatively lower passive resistance at end-of-range then the eight week regimen would be recommended.