As a chiropractor, I get a lot of questions about stretching. How often should I stretch? How much should I stretch? What stretches are good for back pain, neck aches and soreness, etc?
My take on stretching? Don’t do it.
No, it is not the stretching is harmful for you per se. For most parts, it doesn’t make sense (more on this later). Empirically speaking, it’s has very low utility value. The benefits you get given the amount of time and effort you spent doing it just doesn’t add up.
In today’s blog post, we will be discussing everything wrong with stretching.
What is considered stretching?
For simplicity’s sake, we will only discuss static stretching. It is the most studied type of stretching and also the type of stretching most people intuitive do in their daily lives.
When performing a static stretch, we bring a muscle or group of muscles to their endrange. From there, we apply a slight overpressure to attempt to further lengthen out the tissue.
Other types of stretching, which we will not be discussing, includes ballistic stretching, active stretching, dynamic stretching.
What are the purported benefits of stretching?
If you do an online search you will see there are many reported benefits of stretching. However, most of these are not well supported by research. The most common claim is that stretching improves flexibility. However, research has shows that muscle length remains the same even after an 8-week stretching programme!
It is true that people in certain sports (e.g., dancing, gymnast, ballet) tend to stretch a lot. It is more likely that the demands of their sports increased their flexibility rather than that stretching did. Stretching more likely only play an accessory role to their flexibility.
Other purported benefits include reduce risk of injury, increasing sports performance, improving posture, accelerating recovery from workouts, and reducing muscle soreness.
Is a longer muscle better a short one?
In stretching, the muscle is bring to the endrange then pushed a little further with some sort of applied pressure. In other words, the result of stretching is a longer muscle.
Question though … whoever said that longer muscles is a good thing?
The truth of the matter is that muscles are strongest at mid-length and weakest at the shortened and also the lengthened position. Off the top of my head, I cannot think of any reasons why muscles may be better if they are longer.
Sure, you may argue that your range of motion appears to marginally increase after stretching. But what is the benefit of having his extra range of motion? Does this extra range of motion benefit or disbenefit us?
You may be surprise to learn that many studies have reported a reduction in performance after stretching. In fact, a study had reported that stretching can reduce muscle strength by up to 30%!
Here is my question for you: What really is the benefit to having a longer muscle?
Janda’s upper crossed syndrome or lower crossed syndrome
In my opinion, you cannot talk about short (or tight) muscles and lengthened muscles without referencing Vladimir Janda (1928-2022) Understanding Janda’s work can give perspective to how we come to believe that there are benefits to stretch when there are, empirically speaking, none.
Vladimir Janda was a Czech physician and physiotherapist who is known for his conceptualisation of upper crossed and lower crossed syndrome in 1979. Yes, it has been 45 years and, honestly, it would not be unfair to consider it outdated.
Janda’s crossed syndromes refer to an imbalance of muscles that is associated with poor posture and prolonged sitting. His assertion is that this imbalance is the reason people experience pain. The term “crossed” refers to the pattern of muscle imbalance that creates an “X” shape when viewed from the side.
In upper crossed syndrome, the upper trapezius, levator scapulae, suboccipitals, pectoralis muscles groups tend to be tight or hypertonic. In contrast, the deep neck cervical flexors, lower trapezius, and serratus anterior tend to be weak or inhibited.
No evidence to support Janda’s postulation on posture and pain
There are at least two things that we know is not true in Janda’s postulations. First, “tight” muscles is not the reason for the “crossed syndromes”. Second, posture correlate very poorly with neck pain and back pain. We also now know that posture has more to do with psychosocial factors than biomechanical ones.
If we use his conceptualisation, it will make sense to stretch the hypertonic or short muscles while strengthening the weak or lengthened muscles to improve posture and/or pain. However, there is no research to support his claims.
No relationship between muscle tightness and posture
- In 1987, Walker and colleagues could not find a relationship between standing posture versus lumbar lordosis, pelvic tilt, and abdominal muscle performance.
- In 1990, Heino and colleagues failed to find a relationship between hip flexor “tightness” and pelvic tilt.
- In 2015, Mills and colleagues did find a decrease in glutes activation with pelvic tilt. However, there was no reduction in hamstring activation in the “tight” hip flexor group. In other words, there was on need for the glute muscles to activate in order to complete the task. Aka pelvic tilt is not inherently weaker than no pelvic tilt (i.e., able to perform similar task).
No relationship between posture and pain
We have discussed this more extensively in our blog post on text neck. You can check it out for a better understanding of posture as a construct, how it is not new to the 21st century, why it doesn’t cause you pain.
- In 2008, Christensen and Hartvigsen found no relationship between “poor” low back or neck postures and back pain or neck aches and soreness.
- In 2016, Richards and colleagues found no relationship between neck postures and neck pain and/or headaches.
- In 2018, Damasceno and colleagues found no relationship between neck posture and neck pain.
- In 2020, Martinez-Merinero and colleages found no relationship between forward head posture, neck pain, disability, and headache.
I honestly think the evidence is super compelling. Of course it is your prerogative to believe what you want to believe, but yeah … these are the hard facts.
What do we know about posture and pain?
- People with slouched or slumped postures were more likely to be depressed.
- Mobile device use is not associated with muscle and joint aches and pains, even after taking into consideration duration, frequency, and postures of how they are being used.
Stretching doesn’t truly make your muscles longer
Yeah, sorry guys. Stretching doesn’t quite increase muscle length even if you were to stretch it methodologically for eight weeks. The appearance of an increased muscle length is referred to as muscle extensibility. These improvements have been attributed to modified sensation aka you can go more into your end range because you can better tolerate the stretch sensation.
So when you are stretching and you see you can better touch your toes, it is not because your muscles are becoming longer. It’s because your brain is getting used to the sensation of stretching and allowing you to move more into your end range. The true length of your muscle largely remains the same. This is true even if you were to stretch for up to eight weeks!
Shocking, isn’t it?
Why do I feel like I can’t stretch enough?
Perhaps because some muscles are unstretchable? I think this is an interesting hypothesis because it makes sense. I say hypothesis because there is likely no or insufficient data to support it. We assume that the sensation of stretching equals a true stretch. So, if we feel a strong strength equals the muscle is lengthening by a lot. Makes sense but definitely not true.
The idea of how some muscles are unstretchable is because of how they are structured biomechanically. In order to truly stretch a muscle, we must be able to bring it to true end range (i.e., full tension) without other structures getting in the way. This is impossible for some muscles (e.g., quadriceps). I guess you can view it as the body’s own self-protection design to prevent injuries.
Paul Ingraham had gone great lengths to share why some muscles are unstretchable. If you are interested to learn more, you can check out his blog post.
“The most surprising of the unstretchables, because everyone has done a quadriceps stretch, and you probably think you “know” that they can be stretched. However, you were only stretching the rectus femoris muscle — about 10–15% of the mass of the group. It feels like a strong stretch, and it is — of that tissue. But the other 85–90% remains only mildly elongated. The quadriceps consists of four muscles: the skinny rectus femoris and the three huge “vasti” — vastus lateralis/intermedius/medialis. The vasti are only elongated by knee flexion, which is limited to about 120˚ when the calf hits the hamstrings. The vasti cannot be stretched strongly.”
Feeling a deep stretch doesn’t actually tell you how deep your stretch is
Earlier we mentioned that increases in flexibility after stretching is more of a sensation-based phenomenon. That is, you are able to move more into your end range now because your body got “used to” the stretching feeling, and you can tolerate it better to push more into your end range. It is not because your muscle actually increase in length.
This can also be applied here. When you feel a deep stretch during stretching, all there is to it is a feeling of deep stretch. It may not actually be anything close to the tissue’s true endrange. Therefore, it is not reasonable to expect any mechanical properties of your muscles from stretching.
Does stretching really loosen muscles?
You should know by now the answer to this is no. Stretching does not loosen muscles. Stretching can give a temporary improvement in range of motion lasting 30 minutes to 2 hours. However, there is no real change to muscle tissue length even when done for months!
Rubber band gets tighter when you pull on it
Very often I hear new clients telling me that their muscles are very tight, and they also blame themselves for not stretching enough. The idea is tight muscles equals need to stretch or never stretch enough equals muscles become tight. This narrative doesn’t make sense.
If we were to compare a muscle to a rubber band, what happens when you pull on it? Does the rubber band becomes tighter or looser? It becomes tighter! Not looser.
If you were to repeatedly pull on a rubber band to the end of its elasticity for thousands of times, what happens to it? The rubber band loses some of its elasticity and becomes longer (i.e., lengthened). When it is in a lengthened state, aka more loose than before, it has a higher tendency to snap than a new bouncy rubber band!
You may argue that our muscles are not rubber band. You are absolutely right. Earlier, we also shared that performance drops after stretching and that muscles are weaker at the lengthened position. There is really no evidence to suggest longer or more stretched is better.
Knots get tighter if you pull on it
The other narrative I find bizzare is the need to stretch out muscle knots. Muscle knots are like unicorns. Everyone knows what they are, they can describe how it looks, but we can’t actually see it. Not with ultrasound or any form of imaging. Not with a microscope. Some will argue they don’t exist.
No, I am not saying that what you feel is not real. I appreciate that you feel something that feels like a knot. But I can assure you that nobody in the scientific community is able to find this knot. If they are truly tight muscle nodules or bands, we should be able to see them one way or another. But we can’t.
Even if I were to give muscle knots the benefit of doubt, knots become tighter when you stretch them! Think about it. Will you pull tighter on your shoelace if you want to loosen a knot? If there is truly a knot in your muscle, and you are applying over pressure on one end to lengthen it, the knot becomes tighter! Not looser.
Provocative movements can irritate your muscles and cause more pain
In acute situations, such as a new strain or sprain, stretching is more likely to aggravate it than to provide relief. I know many people rush to stretch their injuries. I know that is the advice most people give each other when they feel new aches or pains.
Stretching involves an application of overpressure. On a muscle length, when you are stretching, a tensile force is applied to the muscle. Aka, the muscle is being pulled longer.
Would you repeatedly touch your wound when you cut yourself? No, you wouldn’t! Repeatedly touching your would will make it hurt more. It also delays tissue healing.
Similarly, you will not be pulling on the skin around the wound apart (i.e., stretching) in attempts to facilitate healing. Why then will you be tugging on a muscle that is already strained?
Understand the differences between tissue tightness and perception of tightness
I would say the most clear evidence of a true tissue tightness is if you have a range of motion deficit. If you are unable to bring your elbow to full extension (i.e., fully straightened out your arm), it is possible that there is some tissue tightness.
I say possible because sometimes our range of motion reduce due to our pain. Our pain can result in more sensitivity, which can result in an exaggerated stretch sensation during as the muscle is lengthening, which results in a reduced range of motion.
If you have full range of motion, it is impossible for you to have true tissue tightness! What you have is perceived tightness aka perceived sensation of tightness. But the tissue is not actually truly tight.
Our perception of reality is skewed
It is ridiculously mind boggling to try to “objectively” understand what we feel because we assume what we feel to be true. This is how we make sense of our reality. But what we think, feel, and experience is not always a true representation of reality. Check out the rubber hand experiment. It clearly demonstrates what we feel is not always what actually happens.
Our brain is a ridiculously powerful organ. It shapes our experiences and sometimes it tells us something is happening when it actually isn’t. If you want to learn more about how our brain can influence our pain experience, check out our blog post on pain science.
What happens if I stretch everyday?
Honestly, probably nothing.
Then again, if you think stretching benefits you and you enjoy it, go for it. I don’t think stretching is inherently harmful. But my guess, is that, given you are still reading this, stretching isn’t benefiting you enough for your condition to completely resolve. In other words, stretching gives you some relief but your pain is still there. This is what science is trying to tell you: Stretching does not work.
I hear many wonderful stories of how stretching helps in my yoga class
Many new clients would share that a lot of their yoga classmates have chronic pain that resolved through stretching. They would also often wonder why that is not the case for them. I am not saying that people who stretch don’t feel better. What science is telling us is that the improvement has more to do with random chance than stretching as an intervention.
To give a sinister example, we know that smoking causes cancer. That doesn’t mean everyone who smokes will get cancer! Similarly, that also doesn’t mean non-smokers would not get cancer. I can still get lung cancer even if I don’t consume tobacco products! The probability of that happen is of course much lower than people who smoke.
To give another example, an experiment in 2012 looked at the impact of wearing wool underwear for chronic back pain. Compared to those who didn’t, wool underwear wearers reported less low back pain and more flexibility in their low back. That doesn’t mean the wool underwear cause their back pain to go away!
Also, I have a question for you to consider: How many people do you think stopped going for yoga because it didn’t help with their pain?
Does stretch therapy really work?
If you are using stretch therapy to enhance your general well-being, relax after a stressful day because you enjoy the stretch experience, then yes. I think stretching “works”. But if you are using stretching to improve any sort of chronic pain conditions, I would say no. The evidence simply doesn’t support that.
To give a personal example, I do enjoy massages. Especially during holidays with lots of walking and my muscles are all sore and tired. Do I feel better after? Yes! But will I use massage as a treatment when I have back pain? No.
I personally don’t enjoy stretching. If you are like me, there is no harm in stopping. However, if you do enjoy stretching, please continue to do so for your own enjoyment!
The issue here is not if you can or cannot stretch but more if stretching is useful and bring the benefits as purported. The problem is when there is misplaced expectations on a behaviour. If you are expecting stretching to help you recover from your back pain or neck pain, then you will likely be solely disappointed.
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