Hamstrings get tight and you stretch them to loosen them right? Err well no. It really, really isn’t that straightforward. In this Blog we’ll be taking a whole mind and body exploration of all reasons that hamstrings get tight and then discuss if it’s appropriate for you to actually stretch them.
This Blog is for you if:
- You’ve been endlessly stretching your hamstrings with no gain
- You’re feeling guilty because you feel you should do some hamstring stretches
- You’ve tried every treatment and stretch under the sun but those hamstring just won’t budge
- You’re just interested in biomechanics, latest research and an alternative approach
The reason hamstrings are such a huge topic is that it is the most commonly injured muscles in sport. And in my experience very commonly injured outside of sport too. As such there is copious amounts of research on the subject. Sadly not much of which is very good or relevant.
My aim here is to disseminate the research into chunks that make sense and reference that with what have seen clinically over the last 16 years. Let’s do this…
What Are The Hamstrings And What Do They Do?
Little known to the average Joe there are three hamstring muscles. Biceps femoris, semimembranosus and semitendinosus if you like your Latin. They all originate at the back of the pelvis and attach to either the inside of the outside of the knee as shown.
Their main function according to the traditional definition is to flex (bend) the knee ankle up towards your backside. They also assist the glutes (your backside in case you’re not down with the lingo!) in extending the legs backwards in walking and running. Conversely they resist to motion of straightening the knee. The relevance of this we’ll discuss shortly.
Excitingly, if you’re a geek like me, they also are involved in rotation of the leg. 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. If that’s not motivation to read on I don’t know what is!
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 – the quadriceps on the front of the thigh and the adductors on the inside of the thigh.
The meat is a paler colour which suggests it is made up more of slow twitch muscle fibres which are for endurance, rather than explosive, work. Perhaps this suggests it’s primary function is 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’ve done lots of hamstring curls, deadlifts or sprinting that you’re not used to your hamstring will be stiff and tight the next day. But they should recover. So why is 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
- 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
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. What I like to call a ski jumper’s posture. 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 Are They So Frequently Injured?
I’m sure biarthordial 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 question such answers. So true to form I will! I’m not disagreeing with this statement. I’d just like to 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. You can see what they did there right?
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’d love to show you a picture of the superficial back line here but there are copyright issues! If you’re interested just search images for Superficial Back Line. There are plenty of dubious copies online. I don’t want to add to them!
Instead I’d prefer to offer you a practical example of its existence. All you need to do is test your hamstring length to start with. Perhaps as I’m showing in his video:
Then simply get a firm ball – tennis ball will do, lacrosse ball is ideal, golf ball if you’re very brave – and role it along the length of your foot for a few minutes. Maybe dig into a few painful areas here. Then re-test your hamstring length. You should feel a difference as suggested by this piece of research here.
You’ll notice that this research only talks about the immediate effect. You might get lucky and you’ll never have to stretch your hamstrings again. But this is unlikely. We need to consider the whole body and why there is extra load on the 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 is very relevant.
For the average reader who has better things to do than bury their head in textbooks this is simply a line of muscles that affects rotation and has a large role to play in positioning of the foot which in turn affects the hamstrings.
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.
So, back up straight. Nice big smile. And we’ll continue…
What Increases My Chances Of Hamstring Injury?
Well pretty much everything we’ve discussed so far. Firstly, being unconditioned. Asking the hamstring to perform a level of load it’s simply not used to. 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.
Stress is a factor in all injury. The more stress the more likely we are to get injured. As simple as that. We’ve not spoken about it extensively in this post but if you want out favourite tips for staying relaxed follow this link to our previous Blog: 9 Stress Busting Tips To Keep You Sound Of Body And Mind.
Sitting a lot is another factor. To reduce your risk here’s a link to our video on how to sit correctly. This can lead to the movement pattern involving short hip flexors we spoke about earlier.
Any posture that leads to overuse of the hamstrings in isolation or as part of the very postural Superficial Back Line. To name a few common culprits we see in our clients: 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. All of which commonly lead to tension and dysfunction in the hamstrings.
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 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 the 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.
Being the kind of clinic we are however we like to go beyond this. Why are the quadriceps tight? In our experience it’s (most commonly) due to the hip flexors misbehaving. Putting increase load on the quadriceps. Which can be due to sitting too much and slumped or lazy posture. So we come full circle.
Should You Stretch Your 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. 44 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 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 he 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 you hamstrings by release 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!
I’m not to sure if I’ve helped there or simply confused everyone! Actually, that’s kind of what I wanted to do. The decision to stretch your hamstrings is not a straight forward one.
Consider what your goal is. Are you trying to avoid injury by stretching your hamstrings? In which case perhaps there are better way to do that. Research suggests there are. But that’s for the follow up blog! If you’re a sprinter or speed athlete should you be stretching them at all?
If hamstring flexibility is important for what you’re trying to achieve then by all means give it a go. My personal favourite hamstring stretch is shown in the video above. If you do try it you really need to give it a proper go. At least 6 weeks of holding stretches for minutes rather than seconds on a daily basis.
If you try, or have tried, and it doesn’t do anything for you then maybe look elsewhere. What other tight bits do you have that might be affecting the hamstrings. This is where our biomechanical expertise may be useful to you.
How are your stress levels? Have you tried doing a course of relaxation breathing or meditation? Does that affect your hamstring length? Or perhaps you have long standing pain in your hamstring. You could try stretching the hamstring to see if it calms the nerve signals in the hamstring. Unless it’s too painful to stretch in which case if might just hurt! This maybe is where the relaxation side of our treatments may be of use to you.
I hope I’ve given you freedom from pointless hamstring stretches or opened your eyes to alternative ways to feel better about your hamstrings. Whichever is more appropriate for you.
Coming soon is a follow up Blog: How To Avoid Hamstring Injury And What To Do If You Injure Them. If you don’t want to miss it, or any of our other Blogs please click the button below to take you to our newsletter sign up so we can mail you as each Blog comes out.
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