Hamstring Flexibility Part 2: Passive Stretching

Part 1 of our hamstring flexibility series looked at how to assess for hamstring flexibility using the active straight leg raise.  This week, we will focus on passive stretching to increase hamstring flexibility.  Flexibility can be thought of as the useable range of motion for a given joint and the muscles that act on the joint.  Flexibility is not the same as hypermobility or instability.  Passive stretching aims to increase flexibility by lengthening the muscle without any muscular contraction.  The American College of Sports Medicine (ACSM) recommends at least 2 days per week or more of a targeted stretching program.  Much like the prescription of resistance training, flexibility programs should involve all the major muscle groups.  In cases where a muscular dysfunction is limiting movement patterns, more time and attention will be required to correct the dysfunction.  It is important to understand that flexibility is not a general characteristic, rather it is specific to the joint and muscles involved. Therefore, there are specific strategies for improving hamstring flexibility.  Here are a few of our favorites to help with hamstring flexibility and hip mobility:

Foam rolling: technically this is a form of self-myofascial release (SMR), which we have discussed in greater detail in other posts.  However, foam rolling has shown similar efficacy to passive stretching for improving flexibility.  Since foam rolling does not generally attempt to lengthen the muscle, it may provide an advantage during warm ups prior to competition or exercise.

Towel stretch: Use a towel, resistance band or yoga strap around the midfoot to help pull the leg into hip flexion.  Make sure to keep the leg relaxed and try to pull a little deeper into the stretch with each exhale.

Piriformis stretch:  Place your ankle on top of the opposite knee, and pull the knee towards the chest (see video for demonstration). 

Hold each stretch for a total of 30-60 seconds per each side.  The stretch should be slightly discomforting, but not overly painful.  If it is too hard to hold the stretch for 30 seconds straight perform repetitions of 10 seconds per stretch so that the total time adds up to about 30-60 seconds per muscle group.  This type of static stretching is best performed after a workout or as part of an active recovery day.  Static stretching before competition or exercise may decrease power and strength, since the muscles are lengthened and relaxed.  Instead, opt for dynamic stretching during a warm up and use the static stretching as part of a cool down. 

-Alex Edwards, CEP, CSCS

Exercise Physiologist

Disclaimer:  Articles are based on real cases seen at Scottsdale Sports Medicine. The information on this site is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. All content, including text, graphics, images and information, contained on or available through this web site is for general information purposes only. Please consult your medical professional for individualized healthcare.


Arena, R., Thompson, P. D., Riebe, D., & Pescatello, L. S. (2014). ACSM's guidelines for exercise testing and prescription. Philadelphia : Wolters Kluwer Health/Lippincott Williams & Wilkins, c2014.

Grieve, R., Goodwin, F., Alfaki, M., Bourton, A., Jeffries, C., & Scott, H. (2015). Fascia science and clinical applications: Pilot single blind randomised control trial: The immediate effect of bilateral self myofascial release on the plantar surface of the feet on hamstring and lumbar spine flexibility: A pilot randomised controlled trial. Journal Of Bodywork & Movement Therapies, 19544-552. doi:10.1016/j.jbmt.2014.12.004