Tight Hamstrings: Causes, Prevention and Treatment – Does Stretching Help?

What Are The Hamstrings And What Do They Do?

There are actually three hamstring muscles – biceps femoris, semimembranosus and semitendinosus. They originate at the back of the pelvis and attach to either the inside or the outside of the knee as shown.

Their main function according to the traditional definition is to flex (bend) the knee moving the ankle up towards your backside. They also assist the glutes in extending the legs backwards in walking and running. Conversely they resist the motion of straightening the knee.

Excitingly, if you’re a geek like me, they are also involved in rotation of the leg. We use this fact to maximise our hamstring stretching in one of the videos below. This means, potentially, if your hamstring are not performing their function, you could be more susceptible to rotational injuries. Putting your ligaments and cartilage in a more vulnerable position.

Finally, they are heavily involved in keeping us upright. Leading the fight against gravity so that we don’t all topple forwards onto our faces. This is confirmed in dissection by the colour of the ‘meat’. Hamstring muscles are paler in colour than their explosive neighbours which suggests they have more slow twitch  or endurance muscle fibres. Suggesting it’s primary function may be postural, rather than as traditionally thought, movement based.

Why Do Hamstrings Get Tight?

Let’s consider this in increasing complexity. Fundamentally all muscles will tighten with straight forward overuse. If you do lots of hamstring curls, deadlifts or sprinting that you’re not used to chances are your hamstring will be stiff and tight the next day. But they should recover. So why is it that some hamstrings just stay that way?

To me it suggests continual overload. They are simply working too hard most of the time. The following movement pattern is one we see frequently at the clinic and is a common culprit for hamstring overload:

• Hip flexors which lift your leg up in the air (quite important for walking and running!) become short and tight – often as a result of too much sitting, especially with bad posture or depressive type mood
• This in turn inhibits the opposing muscles (our backside or glute muscles) and their ability to perform it’s function which is hip extension. Pushing our leg out behind us. Functionally this is as we push off the floor with our back leg in running or walking
• This sub-optimal pattern leaves the hamstrings to have to compensate to help out. They are designed to assist in the movement, but they are not designed to do all of the work. This leads to their overuse which leaves them feeling short and tight on a long term basis

I discuss this movement pattern in the video below:

This movement pattern is exactly the reason why pretty much to a man, and lady, all cyclists have tight hamstrings.

The postural role of the hamstrings is a further reason for overuse and tension. Anyone with a leant forwards posture will cause the hamstrings to overwork to stop them toppling forwards. This posture can be reflective of a freeze response to stress. As if bracing for impact. Which also give generic tension through the body, not just hamstrings.

I like to call this ski jumper’s posture. This picture is of course somewhat exaggerated of what I see but hopefully you get the idea. People who have this should notice that when standing they have more weight on the fronts of their feet rather than spread evenly through the whole of their feet.

Why Wouldn’t My Posture Be Prefect

Hopefully the previous section made sense to you and you can get a sense of how important posture is to what your hamstring get up to. But why would your posture be sub-optimal and therefore ask more of the hamstrings?

Previous injury is what is cited in all the literature. This could be direct injury to the hamstrings. Or indirectly quadriceps (thigh), adductors (think groin injury) and glutes (think bottom). But something had to lead to the first of those injuries surely!

I’d say that life was the biggest influence on our posture. Everything that’s gone before. So yes, absolutely previous injury is a factor. Especially serious ones or ones that worry us. Every emotion has an associated posture and over time that changes the way our bodies work.

Assuming you’re sat down right now slump (if you’re not already) in a kind of really hacked off kind of way. Notice how it feels in your body. Put a few of these days back to back and imagine the impact on your body. But a few months or years of this kind of posture and you can get a sense of the profound affect posture and mood can have on our biomechanics.

Here’s our video on the best way to sit to avoid such issues, originally filmed for our inguinal hernia article but just as relevant here:

Why Are They So Frequently Injured?

I’m sure biarticular is the word that’s on the tip of your tongue! In plain English that means that the hamstring muscles go across two joints (the hip and the knee) unlike most muscles which just cross one joint. These muscles are more prone to injury.

This is a standard physiotherapy answer. Regular readers will know I like to dig a bit deeper so let’s consider some more options.

We’ve been speaking about the hamstrings role in posture. So far I’ve neglected to mention that the hamstrings are just part of bigger functional unit that opposes the pull of gravity. The fantastic biomechanical bible that is Anatomy Trains calls this the Superficial Back Line – because it involves the superficial muscles on the back of the body.

Effectively these are an entire group of muscles that run from the base of your foot all the way to back of your head to work to keep you upright. Any tension on any part of this line can impact tension and therefore vulnerability into the hamstrings. I’ve included the representation of the superficial back line that we’ve had commissioned below so you visualise the concept:

You can see this in action as I demonstrate in the video below of how to stretch your tight hamstrings… and a few associated muscles too. Using a forward fold I include a stretch into the muscles in the back at the same time as the hamstrings to give a fuller stretch through the back of the body:

What I forgot to mention in the video here is that you can do a little bit of self treatment whilst you’re in these stretches. You can either use your fingers to release the tight bits or if your feel brave dig a tennis or lacrosse ball. You may also get some release of the hamstring by releasing the arch of your foot. Refer back up to the picture of the superficial back line above if you’re wondering how that might work. You should feel a difference as suggested by this piece of research here.

If you do read the research you’ll notice how it only talks about the immediate effect. You might get lucky and you’ll never have to stretch your hamstrings again. But, more likely, we need to continue to consider the whole body and why you specifically have extra load on those tight hamstrings.

For any fellow therapists out there, Anatomy Trains aficionados or just very keen amateur readers we could also consider the role the hamstrings play as part of the Spiral Line. Look into it if you’re interested. It may be very relevant for you and I have seen that many times at the clinic. But there is only so much we can consider in this article!

What Increases My Chances Of Tight Hamstrings Causing Injury?

Well pretty much everything we’ve discussed so far but weirdly not actually hamstring tension. Many studies have been done which suggest that the tightness of your hamstrings is not as much of an accurate predictor of a hamstring injury as you would think.

Interestingly none of the studies that I looked at considers the whole biomechanical picture we’ve discussed above. More fool them! Whilst the Anatomy Trains model is not accepted science (yet) I see daily evidence of it’s existence and that knowledge has helped countless people with recurrent hamstring tension.

What is consistently cited in the literature is a history of hamstring injury. So If you’ve had an injury before your more likely to injure your hamstrings again. And age. Sorry. But we all knew what anyway didn’t we.

In my opinion hamstrings get injured when we’re asking them to do too much for what they’re conditioned for. The amazing thing is, despite everything I’ve mentioned above, the human body will always adapt. If you train in the right way, even with a very dubious movement pattern, your body will cope. Just watch a bunch of amateur marathon runners. I can’t take my biomechanical eyes off them! All shapes, sizes and ways of moving.

So theoretically anything that is extra tight in that superficial back line can cause the hamstrings to over work. The most common culprits we see in our clients: are: the plantar fascia on the sole of the foot, calf muscles, the erector spinae (the muscles next to our spine) and the muscles which hold our neck up. We often see an improvement in length and function of the hamstrings when we treat a number of these structures.

These thoughts are backed up by this research which suggested a limitation in ankle bend (dorsi flexion) is a predictor of hamstring injury. This limitation is frequently a result of calf and plantar fascia tightness as part of the superficial back line.

Another concept we’ve not expressly considered so far is the muscles that oppose the hamstrings. Specifically the quadricep. This would make sense of the finding that most hamstring injuries occur as we reach our foot forwards – they ‘go’ when they are opposing the quadriceps. This piece of research backs up the link between quadricep tension and hamstring injury.

Why are the quadriceps tight? In our experience it’s most commonly due to the hip flexors misbehaving. Putting increased load on the quadriceps. Which can be due to sitting too much and slumped or lazy posture and so we come back to our discussion of posture.

Stress is a factor in hamstring injury and hamstring tightness. Simply put stress increases our sensitivity of our body and we simply feel more pain. Not only that but we tend to be more tense through our whole body. Tense muscles don’t work as well. We consider the affect of stress on injuries in our previous article Does Stress Cause More Pain? Yes being the answer for those short on time!

As I seem to mention in all my articles having a good wellbeing routine in place to help us through the intricacies of life reduces tension and sensitisation throughout our bodies. Our clients who are able to implement some of wellbeing advice will invariably fair better than those that can’t. Our best collection of wellbeing tips is our previous article on mindfulness.

Should You Stretch Your Tight Hamstrings?

This may seem an obvious question but it really isn’t. Stretching is a really interesting and, believe it or not, controversial area in physiotherapy.

Does stretching actually do anything? I discussed this idea in great detail a few years ago in a previous blog where I questioned as to whether you should bother stretching at all. My views are more moderated now. Especially having benefited from taking up yoga. But what does stretching actually do?

You might think that stretching elongates the muscle. But most research suggests the muscles returns to its original length within a matter of minutes. So why does stretching ‘feel’ good? Why do people who stretch a lot get more flexible? Yogi, gymnasts and dancers immediately spring to mind. 46 year old ex-swimmers do not!

Well, changes to tissue length take weeks, if not months. That’s the truth. So yes, with a continual stretching regime you will improve. Short term, however, it is thought that stretching calms the nervous system in the muscle being stretched. Which is why it feels nice. This is why after a full body stretch like yoga we feel mellow afterwards. Our whole nervous system is calmed.

Calmer muscles feel less. Is this good? Perhaps for muscles that are in pain. But maybe not for muscles that need lots of feeling in them to perform at their maximum capability. Certainly sprinters don’t stretch. I don’t think I’ve seen a weightlifter stretch. It reduces the amount of torque the muscles can pull.

This nice summary piece of research here also backs this up. It suggests that general stretching has no impact on the incidence of injury. Another study here suggests stretching improves joint range of movement… so long as there are no significant muscle restrictions. This would backup what I have seen clinically over the years. If there is no biomechanical reason for the limitation in hamstrings then they can, and do, improve. But, if there is a biomechanical limitation away from your hamstrings, then perhaps you’re wasting your time stretching your hamstrings. Maybe you’d be better stretching reasons why the hamstrings are tight. This is what I spend my life doing!

There are further anatomical considerations that bring the need to stretch hamstrings into further doubt. Increasing fascial (connective tissue) research shows how force in not only dispersed up and down the muscles along the line of the muscles fibres. But also transversely (thought to be about 40%) across the adjacent muscles.

This means that potentially the quadriceps and adductors could have more of a bearing on how tight the hamstrings feel than the hamstrings themselves. Indeed, if we delve into some very geeky anatomy we can see really thick strong fascial connections from the fascia on the outside of the thigh that continue onto the hamstring. If tight this can hugely impact the range of the hamstrings.

I appreciate we’ve gone deep here! For those that are interested take a look at this anatomical representation. Look specifically at the bottom two circles and consider the size of the fascial connection next to biceps femoris (main hamstring) out to the a adjoining muscles.

Practically this can mean you can release your hamstrings by releasing this very specific line behind your IT Band and your hamstring. Good luck getting to that with your foam roller. It really needs a skilled therapist. But if you do manage to hit the right spot you’ll know all about it!

In short there is no strong evidence that stretching does help the tension in your tight hamstrings. Certainly not in the short term. This is backed up by this piece of research that suggests functional rehab and core work is more effective at preventing hamstring injury than stretching and strengthening. Regular readers will know I’m not a massive fan of core work (see previous article: Core Exercises: Is There Any Point?)

From our experience at the clinic I would prefer to replace core work with consideration of everything other than the hamstring that can affect the hamstring as we’ve been discussing. Core can be a part of that, if you find it of benefit, but we normally find the ideas we have been discussing more relevant to our clients.

Conclusion

Hopefully you can now see that the decision to stretch your hamstring is not a straight forward one. In short if you find it beneficial then of course crack on. But if you’ve been stretching them for some time with little result then I’m hoping this article will free you up from that burden and you can use your time more productively. Safe in the knowledge that hamstring tension doesn’t mean you’re more likely to injure them.

Better to work on your over tension and sensitivity to life and address the multitude of ideas in this article as possible causes of your tight hamstrings. If you’re still keen to stretch those hamstrings consider why and when best to stretch them. After exercise may help recovery a bit. Before exercise makes them weaker – so avoid then. Better to do a decent warm up and some dynamic hamstring stretching.

If you do want to improve that hamstring flexibility you not only need to stick at it but also consider all of the ideas in this article and possibly more. This is why I have 90 minutes with each of our clients in every session. You’ll most like need at least 6 weeks of holding stretches for minutes rather than seconds on a daily basis to see specific lasting changes in the hamstring length.

If you’ve been struggling with tight hamstrings and their implications for a long time then we strongly recommend seeking professional advice and where appropriate treatment. Whether that’s with ourselves and anyone else for that matter.

If you’re lucky enough to live in or near Brighton and unlucky enough to have a hamstring problem our contacts details are at the top of the page! If you’d like more information on how we work please click the following link: Brighton Physiotherapist.