Why Are My Hamstrings Always Tight?

Introducing The Concept Of Relative Stiffness

So many of us speak of tight hamstrings after running. The description has become a bit of a throw-away line when talking about  one of the common aches and pains we feel from the rigours of our training.

If you feel this too, you should stretch your hamstrings more… Right?

Well, probably not to be honest! 

In my experience, so many runners fail to maintain a neutral pelvic position as they move. This is most likely due to a lack of core strength, and hip flexor (often Rec.Fem.) tightness. The pelvis tilting anteriorly increases the distance between hamstring origin and insertion, lengthening the hamstring muscles and increasing tension.

The video above does a brilliant job of explaining the concept of relative stiffness. This describes the interplay between core strength, pelvic control and hamstring tension.

It’s quite possible that your hamstrings aren’t tight because they’re chronically short. As an endurance athlete, you probably haven’t acutely injured your hamstrings by running – this is more frequently a sprint related injury.

It’s far more likely that the feeling of tightness is there because the hamstrings are being held in a lengthened position due to poor pelvic position and core weakness.

Before you spend ages performing static stretches for your Hamstrings. Perhaps instead work on building core strength and achieving and maintaining proper pelvic control as you move!

Last updated on March 2nd, 2021.


  1. Hi James,

    It was really of great help..Thank you..:)
    Can you suggest me some exercises to relieve the pain in Calf-muscles ??

    Thanks in advance.

  2. I get what you are saying about relative stiffness and I totally agree…however,,, I went out yesterday and ran 16 km trail run with hills. My average run is a weekly 8-10 km. Consequently, today I am experiencing completely natural hamstring stiffness. Sometimes it’s not rocket science ….you use a muscle more than it has been used previously and it stiffens because it has been worked.

  3. Great Info. Spot on.

    Thesocialphysio – the “stiffness” you describe in your comment may be exactly what James is referring to. The pulling down of the pelvis during a run (e.g. by short dominant quad muscles) can result in the hamstrings being held in an overlengthened state for an extended period of time. Trying to lengthen them even more by stretching them may not therefore help. What they need is to be relieved of their “tautness” by lengthening the quad muscles (rectus femoris) and/or hip flexors (psoas) thus allowing the pelvis to return to a neutral position.

    The same applies to the rhomboid muscles under the shoulder blades. After a day on the computer or on a bicycle, they feel tight and the temptation is to put your hands together infront of you and stretch them, when in reality they are “taut” and need to be relieved by sretching the chest instead.
    Hope this provides food for thought.

    1. Yes I definitely agree with what your saying about muscles often being in a lengthened position and what they often need is to be taken off stretch.

      I think there is a bit of grey area though with h/strings. Particularly if people are actually spending the majority of the week in a seated position (even if they’re running regularly), which mostly dictates that the hammies will be in a shortened position. Obviously this will vary depending on how serious an athlete/runner we’re talking about.

      For sure though I certainly see a LOT of people running, or even standing, with an anterior pelvic tilt and massive lumbar lordosis!

  4. Hi James
    Agree with you totally and often people are surprised when we say that it is not really a hamstring problem. Just to add something else I often see with people complaining of tight hamstrings is what I call early knee flexion. From video analysis I see that the knee starts to flex (bend) whilst the support foot is still in contact with the ground and should be producing power into propulsion. It is unable to do this as the knee starts to flex (often with an anterior rotation of the pelvis) and so the runner loses both foot stability and eccentric load of the hamstrings at this crucial time of the gait cycle. This forces propulsion to become more of a lift and swing of the leg from the hip flexors and quads and so this is why these muscles groups become tight and overused. This will always create the over stride contact position as the unstable / weak hamstrings and gluts cannot control this rapid swing phase. This creates high impact forces, rapid pronation (if the foot is of this type) and the inability of the foot to recover / resupinate into propulsion. So sorting out foot stability at propulsion is essential with running form, footwear and sometimes orthoses.

  5. Thanks for the post! Great comments on the role of the quads and hip flexors- I actually, just completed a blog post (shall post in next few days) on the importance of quadriceps stretching to reduce hamstrings soreness and stiffness. The quads and hip flexors are so dominant that the hamstrings are constantly under tension. So a simple quad stretch can help alleviate that discomfort. In addition, I have found that rolling the hamstrings can be more effective than stretching. Because they are under stress restrictions will occur in the fascia. You can mobilize the restrictions more effectively (with rolling) which may be causing the tension/discomfort.

  6. Would this still apply if I only feel the stiffness in one leg, or could it be from something else?my stiffness only starts to show itself at about the 20-25 min mark of my runs.

  7. This is a good post to highlight relative tightness/stiffness. However the video is a poor demo. When the athlete is cued to flex Lx spine (with core muscles) he’s posteriorly rotating pelvis and ischial tuberosity is shifted superiorly and anteriorly.

    This will move hamstring origin – allowing that extra hip flexion (without hamstring changing length or stiffness).

    “Activating the core allows the hamstrings to relax” is a dubious claim to make!

    Reducing pelvic anterior tilt will change the length-tension relationship of the hamstring – possibly causing chronic tightness. But it wouldn’t be the FIRST thing i look for when someone comes in complaining there hamstrings are tight.

  8. This is a good demonstration but the explanation could be a little more detailed. Posteriorly rotating the pelvis also changes the position of the hip joint and the attachment of the hip flexor muscles which are responsible for raising the leg up.

  9. Mark firstly you have assumed that by “reducing” anterior pelvic tilt that you have the potential to cause chronic tightness. Unless you mean in the context of reducing the alignment into a posteriorly tilted position from neutral I would disagree. Tightness does not always correlate with shortening, as illustrated in lower crossed syndrome where the hamstrings are tight by result of increased distance between their attachment sites. That’s why stretching “tight” muscles may provide short term symptomatic relief through mere change in tension, but long term feed into the issue. The length tension relationship sits over a continuum and ideal tension is within a range not at a set value.

    The concept of relative stiffness illustrates the important interaction of tension variation throughout the body and feeds directly into the joint by joint approach introduced by Cook and Boyle. Whilst mobility and fascial release is impirtant they are futile without re-establishing tension in appropriate regions of the body. To be honest most the stuff you read on blog’s are simply brief snippets of glamorous information that provides only a glimpse into the bigger picture. Look at Kelly Starrets stuff, people have been sucked into belief that mobility exercise and foam rolling will cure there chronic issues for good.

    With no disrespect to the author, this stuff has been reproduced over and over again for the past several years by a copious amount of “gurus”. If you don’t believe me check the publication dates of similar content written by guys like Eric Cressey, Dean Sommerset, MikeRobertson, Boyle, Cook, Mike Reinold……the list goes on. The difference is these guys understand the greater picture, and simply provide condensed “sexy” snippets for interesting reading and cult internet following. Uneducated people who are too lazy to fully explore the concepts in research articles, texts etc then take this stuff and run with it as if it were there own. I am
    Not saying this is what this author has done because his practical experience speak for itself and his coverage of more broader issues seem quite good. It’s more the keyboard warriors that jump of comment sections to preach their gospel without ever picking up a text book, without ever learning to appraise research, without ever putting on a pair of running shoes, without ever lifting a weight in their life.

  10. Hello Christian,

    I agree with you! I was alluding to the fact that sagittal plane movement of pelvis will change the relative attachment point of hamstrings which may or may not cause tightness – whether it has any clinical significance or not. Muscle length, tension & stiffness are different things and as you say, the causes of a problem can be over simplified in blogs.

  11. hey…thanks so much….this is such a ray of hope…so in order to maintain a neutral pelvic position should I make a conscious effort to keep my back straight while running??……….also the fact that i am able to touch my toes with my legs outstretched and my head resting on my knee…is evidence that i don’t have short or tight hamstrings??….also why does twisting my toes which causes a cracking sound ease the tightness somewhat?……please do reply….thanks again!

  12. This is very interesting. I went on a run and almost had to stop because my thighs (perhaps my ham strings) were so stiff and the strings at the back of my thighs hurt two days later. I also had a bad lower back hernia, that I was told may related to weakness in my “core”. Who? I would like to know more about the exercises that that you mention “classic crunches planks something something bands and medicine ball work”.