We are all juggling life responsibilities be it work, school, family, friends and recreation so much so that we often times relegate our recreation to the weekends.  In an attempt to make up for not exercising all week we tend to overdo it placing ourselves at risk for injuries.  Hamstring strain injuries are one of the most common types of non-contact injuries experienced during sports activities and exercise accounting for 12%–16% of injuries, with a reported re-injury rate as high as 22%–34%. These injuries typically occur during sports activities that involve rapid acceleration/deceleration and fast running like recreational weekend basketball, softball or football.  A common culprit in these reported injuries is a lack of flexibility in the hamstrings which also result in major muscle imbalances, which can predispose us to muscle injuries like patellar tendinopathy, patellofemoral pain, and the development of low back pain.  The eccentric contraction of the hamstrings that occurs during the late swing phase of running to decelerate knee extension has been reported to be associated with such injuries.

In a study lead by Masahiro Iwata on the effects of dynamic stretching on hamstrings flexibility conducted out of Nihon Fukushi University the following key findings were uncovered:

  • Dynamic stretching increased range of motion and stretch tolerance, and decreased passive stiffness.
  • Stretch tolerance returned more rapidly after dynamic stretching than other measurement indexes.
  • Dynamic stretching performed prior to exercise is useful for improving hamstring muscle flexibility.

Therefore given the findings in conjunction with the fact that increased passive stiffness of the hamstrings and decreased knee ROM are both risk factors for hamstring injury during sports, it would behoove athletes and weekend warriors alike to include dynamic stretching of the hamstrings before exercise as a means to prevent hamstring injuries. 


Journal of Sports Science and Medicine ( 2019 ) 18 , 13 – 20