- Julius de Jong
Why We Should Stretch More (Episode 26-39)
When we can let go of tension, our world changes
For one year, I’ve committed to researching 39 ideas that make life better. Both for myself, and others. You’re currently reading number 26, of 39. Every 9 days, I’m diving into a new topic to learn and expand my thinking. Although at times I’ve felt anxious and stressed about making my deadlines, many times posting only minutes before midnight on day 9, every time I am grateful for the experience. This time is no other. Wow, how I discovered an entire new part of myself in these nine days. I’m 39 years of age, and have experienced, seen, and read a thing or two, but this topic, and the practice of it, blew me away. In essence, I’ve researched stretching. However, I ended up with much more. I learnt and gained new insights about tension, and especially, about letting go. I learnt about how our mind, like tension in our body, can keep us stuck for years on end. What I also learnt by means of physical experience, is that this all can shift and change, in merely a few days.
My deep interest in stretching started in 2020. I then read David Goggins’ book ‘Can’t Hurt Me’. For those of you reading this, who’ve not yet had the pleasure of reading his book, I highly recommend it. It is an autobiographical story of a young man and his journey of redefining himself and overcoming his own limitations in the process. It is a unique story of mental and physical toughness at a very high level. It’s also a story about a hard-learnt lesson teaching the need for balance. David Goggins transforms himself from an overweight and depressed young man without prospects into one of the world’s most unique and extreme athletes. He went against the odds and rejection and became as U.S. Navy SEAL, surviving 3 Hell Weeks. He has an enormous string of athletic performances to his name ranging from ultramarathons to ultra-triathlons, a world record for doing 4030 pullups in under 17 hours (by now, broken already a few times), and more. Clearly, he has pushed his body and mind to the limits. In the process, Goggins had created so much tension in his body that at some point, he became severely ill. Doctors were unable to help him, and no medication could alleviate him from his self-educed suffering. David Goggins initially didn’t believe in the value of stretching. However, after having developed an enormous knot at the back of his neck, and other ones above his hip flexors, he thought back of Joe Hippensteel, a man whom he got to know during his SEAL training where Joe had taught stretching and advanced training methods to the SEALs. Goggins reached out to Hippensteel and got to work. Through stretching for up to 12 hours per day, he stretched himself back to health. As he had said, Hippensteel had saved his life. In his book, Goggins wrote, ‘I came up with a routine, starting at my neck and shoulders before moving into the hips, psoas, glutes, quads, hamstrings, and calves. Stretching became my new obsession. I bought a massage ball to tenderize my psoas. I propped a board up against a closed door at a seventy-degree angle and used it to stretch out my calf. I’d been suffering for the better part of two years, and after several months of continual stretching, I noticed the bump at the base of my skull had started to shrink, along with the knots around my hip flexors, and my overall health and energy level improved. I wasn’t anywhere close to flexible yet, and I wasn’t completely back to myself, but I was off all but my thyroid medication, and the more I stretched the more my condition improved. I kept at it for at least six hours a day for weeks. Then months and years. I’m still doing it’ (Goggins, 2020).
The man who got Goggins on his stretching routine is the man whom I interviewed to learn about stretching. Joe Hippensteel is educated in Physio-Kinesiology and spent many years training for the decathlon at the USnational level. He lacked natural talent and size, yet his accomplishments were developed through extremely hard work and creative, extremely advanced methods of training over a period of 30 years. His focus became to out-train and outsmart everyone (Hippensteel, 2022). Joe’s intense training averaged 8-10 hours per day, for 5-6 days per week for many years on end, keeping up with the much taller, stronger, and faster athletes.Although he did not reach his goal of making the Olympic team, he developed many creative and intense training methods that allowed him to improve his performance to reach a national level. One of his theories for this was his kangaroo-theory, aimed at developing massively powerful legs. At some point, he was squatting twice his body weight, for ten sets of ten reps. However, as it had done for David Goggins, also for Joe this resulted in the development of enormous tension in his body and increasing ailments and pain. Doctors were unable to provide solace, yet Joe didn’t want to give up his training. Ultimately, this led him to discover the power of stretching. As he learnt, power and strength must be balanced with flexibility (Hippensteel, 2022).
Tension and muscle lock
We build up tension through lifestyle, repetition, and overuse (Hippensteel, 2022). Continuous recurring motions or overuse results in tension in our muscles and can ultimately result in muscles locking up, forming a tight know of contracted muscle fibers. Right before two Olympic trail competitions, Joe pulled a hamstring. The advice was surgery, but instead, he started applying trigger point massage and stretching. When he got his nose down to your knees, the problem was gone. ‘It was as if I pulled a kink out of the muscle’ (Hippensteel, 2022). Thus, when we stretch long enough to reach the desired range of motion, tension unlocks, and the muscle resets itself in a way. A muscle is locked to more or less extend when it’s not able to reach its full length. If it’s not full length, a muscle starts aching, we feel pain, and the muscle starts tugging on our tendons and joints (Hippensteel, 2022). To unlock our tight and locked-up muscles, we need to lengthen them through stretching.
To alleviate his injuries, Joe had tried all the different supposed remedies such as particular strengthening training, acupuncture, and a wide range of specific therapies. He tried everything, except injections or surgery, but nothing worked (Hippensteel, 2022). While applying self-massage, and through prolonged stretching, Joe discovered the body has neutral points. ‘When we reach a level of flexibility in a particular range of motion, all of a sudden the pains and aches leave our body. It simply stops hurting’ (Hippensteel, 2022). From this discovery, Joe started finding more neutral points, which he then developed into a standard. He identified 24 ranges of motion for which he developed a standard for stretching and human flexibility. No one had ever set a standard for human flexibility, and our natural ranges of motion, yet we need a system if we want to train and stretch effectively (Hippensteel, 2022).
Range of motion
Through a methodological approach, we are able to gradually build our body back to the ranges of motion of when we were young (Hippensteel, 2022). Growing up, and continuously engaging in repetitive behavior and movements, we lose our flexibility and experience a limiting in our range of motion. This doesn’t have to be the case, and we can return to the flexibility and freedom of movement we once knew as children. ‘Every kid can do all my ranges [of motion]’ Joe says (Hippensteel, 2022). ‘Range of motion (ROM) measures the distance and direction that a joint can stretch’ (Quinn, 2021). We can assess our range of motion by measuring the degree to which we can straighten, bend, or rotate a particular joint. If you can do all the ranges of motion freely, your posture will be perfect and neutral. The following joint movements are possible in our bodies (Dawson et. al., 2021):
Extension: Straightening a joint. When you straighten your knee or elbow, for example, you increase the angle between the bones at these joints;
Flexion: Bending a joint. When you bend your knee or elbow, you decrease the angle of the bones at these joints;
Abduction: Movement away from the center of your body. A good example is doing jumping jacks or lifting your arm or leg to get dressed;
Adduction: Movement back to the center of the body. A good example is returning your arm to your side after waving or standing with your legs together.
Washington State Department of Social & Heath Services offer a useful overview in their ‘Range of Joint Motion Evaluation Chart’. However, it’s worth noting that the stretches and range of motion as identified by Joe Hippensteel in some cases exceed the degrees mentioned in this document. For instance, as he discovered, a shoulder extension stretched up to around 120 degrees alleviates shoulder injury such as bicep tendinitis, as I’ve been experiencing from personal experience, while the before mentioned chart mentions a mere 50 degrees.
Benefits of stretching
‘Stretching is an intuitive movement, not only for humans but animals as well. We stretch because it is a simple and effective way to loosen our muscles and invigorate our bodies. As we get older, our muscle mass naturally decreases and our activity levels decline. Inevitably, muscles grow weaker and joints stiffen up. Stretching can help reverse that aging process. Whether you are young or old, athletic or sedentary, stretching is a great way to improve your fitness and agility’ (Liebman, 2017). ‘If you don’t have full range of motion, you’re limited in regard to how much fuel you can store in your muscles for energy, and […] you’re not going to be free to move’ (Hippensteel, 2022). For example, if you can’t move your legs fully to the back while running due to tight hip flexors, you’ll end up working twice as hard with your hamstrings and glutes pulling your legs back (Hippensteel, 2022). Tightness in the hip flexors prevent you to get the full stride length that you need. Stretching helps restore our natural range of motion. Throughout this practice, it rejuvenates us. Stretching is the fountain of youth, as mentioned by Joe Hippensteel during our talk. Through stretching, we become able to use more tissue of the muscle which previously remained locked in tension. ‘The common denominator is tension. Eliminate the tension, increase range or motion, and you’ve sold the problem’ (Hippensteel, 2022). When we stretch, we will become able to tap into more muscle fibers and therefore our workload will be easier. Through this, stretching helps unlock the muscle fibers we are not using due to tightness. According to Joe, all the medical labels such as arthritis, bursitis, tendinitis, bulging disc, migraine headaches, tennis elbow, restless leg syndrome are all caused by tension (Hippensteel, 2022). As he claims, by achieving his standard range of motion through doing stretches, tension goes away (Hippensteel, 2022). Stretching thus helps us alleviate tension and heal. ‘The human body has an immense capacity to heal itself. At any age, and in nearly any state, the human animal is capable of an incredible amount of tissue repair and remodeling’ (Starrett, 2015).
Joe Hippensteel’s approach to stretching
According to Joe, the missing link is flexibility to a standard with a plan. I can attest to this. When we know what we need to do, when, and for how long, life simply becomes more enjoyable. In the approach of Joe Hippensteel, typically the static stretches are held for a period of two minutes. After this, you lay down, flat on your back for one minute. This is called the dead zone (Hippensteel, 2022). This helps the muscles and the newly extended fibers to get blood and oxygen. The dead zone part is a very important part of the stretching routine, as is rest for muscle growth in training. Similarly, the longer duration of stretching (for two minutes) is very important. This is not regular practice. Most stretching advise is about holding a stretch for 15 seconds, 30 seconds or in the more extreme cases, 60 seconds. With the approach of Joe Hippensteel, this is much longer. As he explains, it is when you hold the stretch for a prolonged period of time, the tension is able to release (Hippensteel, 2022). This longer duration is important as it allows for time for the muscle to relax. ‘Only a relaxed muscle will allow itself to be stretched’ (Wharton, 1996). Joe distinguishes between a building and maintaining phase. In the building phase you spend time to increase your flexibility and extend the length of your muscles back to their natural size. The building phase can last somewhere between one and a hundred hours, but ultimately, the body opens up again returning to the full range of motion we had as a child (Hippensteel, 2022). After that, the maintaining phase is about keeping the flexibility and sustaining a full range of motion.
When stretching, Joe advises never to go passed a seven out of ten in pain. It’s at this pain level, the body is still able to relax. With higher levels of pain, we will be unable to release the tension and remain tight (Hippensteel, 2022). I asked Joe how we know when we’re at a seven out of ten in pain. As he explained, when our face is starting to tense in pain and starting to show a grimace, then one is crossing the border line over a seven in pain (Hippensteel, 2022). With stretching, the maximum is a seven, while at trigger point work, we can go up to an eight. As he illustrated from his experience working with the Navy SEALs, they tend to think that more is always better. However, when it comes to pain sensations while stretching, this is not the case. One should not exceed seven out of ten.
The importance of breathing and relaxation
By calming down, muscles will release tension easier (Hippensteel, 2022). For this, relaxation is critical. We’re ‘on’ sixteen hours a day, focused, performing. Our bodies need more down time, so our system can recover and reset itself. With that, meditation and breathing techniques can be helpful, in addition to a stretching routine. We have to allow the muscles to relax and use the mind to feel this and focus in on it (Hippensteel, 2022). The aim should always be to continue to breathe while stretching, in a regular, relaxed pace. ‘Each time you pull air into your lungs, your diaphragm contracts, pressing down on your internal organs and blood vessels. As you exhale, new blood flows through your entire system. The new blood flow helps improve the elasticity of your muscles’ (Tuffelmire, 2022). Breathing helps our mind and body relax, and when we relax our muscles can extend and range of motion increase. To learn more about breathing, and how this can help you relax more, read my post on this topic here.
Static- versus dynamic stretching
As Joe shared during our talk, virtually the entire athletic world has locked onto only doing dynamic stretching prior to a workout (Hippensteel, 2022). This is incorrect. Instead, Joe emphasizes the importance of extending the length of the muscle through long durational static stretching. When one is not flexible and able to do so, though the building phase of the stretching routine, the goal is to achieve this. Then, once achieved, the goal shifts to maintaining this flexibility and length of the muscles. As he explains, ‘if you run a full marathon, you’re not going to be able to stretch for a while right after the [race]. But leading up to [it], if you’re maintaining your full range of motion, not only are you keeping the length [of the muscle] and the tension away, you’re [also] allowing the fibers to be open and absorb more fuel which you can use in the marathon’ (Hippensteel, 2022). When you’re only doing dynamic stretching, combined with repetitive training and tension, instead of really stretching the muscle, it continuously is getting shorter and shorter, with tension increasing (Hippensteel, 2022).
Mobility versus flexibility
It’s good to understand the difference, as these terms are often confused. Mobility is being able to move to a certain range of motion freely. However, if it’s not a full range of motion, it is merely mobility in a limited range. Flexibility on the other hand means being able to move through the full range of motion, unlimited (Hippensteel, 2022). Our goal should always be flexibility, and mobility will be the result as a consequence.
Proper warm-up routine
During our talk, we spoke about stretching in relation to warm-up for athletic performance. Joe Hippensteel explained there are four parts to a good warm-up. The first thing is to do some relaxed cardio to get your blood flow going. Secondly, you need to do static stretching, focusing on lengthening the muscles and the relieving of tension. Thirdly there is the dynamic stretching, and fourthly you do a sport/workout specific warm-up. From these four, the cardio and dynamic stretching our optional, but the static stretching and the sport/workout specific warm-up both are mandatory. When doing this, not only will you be pain free, you’ll also be able to put more effort into your training because you won’t be worried about hurting or straining a painful spot (Hippensteel, 2022). Also, the more the muscle fibers are open, the more fuel you can store, and the more oxygen can reach your muscles. There is a lot of talk that supposedly stretching inactivates muscle fiber. It doesn’t, explains Joe Hippensteel. Instead, stretching helps unlocking locked muscle fiber, and refuels it with calcium and magnesium which help regulate muscle contraction.
Tightness and the mind-body relationship
During our talk, I asked Joe about the relation between the tightness in our thinking and its reflection in our physiology. Joe illustrates the power of this by a hypothetical example of a doctor treating your shoulder due to tightness. The doctor suggests it might be arthritis and bursitis in the joint. He’s treating you with e-stim, and is doing ultrasound, and it all appears to be very serious. ‘If you’re locked into what the doctor’s limits are, you’re not able to expand your physical capabilities because you’re locked in mentally’ (Hippensteel, 2022). This is a very important point to me. For this reason, we should be very cautious as to who and what sources we allow to influence our thinking and the view of ‘reality’ and what’s possible. Therefore, it is important to keep expanding our knowledge, thinking and intuition.
There is a direct relation between rigidness in our thinking and tightness in our body. As soon as our thinking becomes more relaxed and openminded, our body follows. Vice versa, when we address the tightness in our body, this helps us become looser in our thinking. Therefore, when we learn to release physical tension, we become more open, forgiving, and loving. Our mind and our body are not two separate systems. They are intrinsically connected. As Joe stated, ‘[i]f you can control the mind, you can control the body’ (Hippensteel, 2022). Personally, I believe there is even something beyond this, which is not merely controlling, but essentially allowing without judgement (tightness) whatever emerges. From there, a subsiding of these thoughts, feelings, emotions, and tensions becomes possible.
Joe rightfully pointed out that the tension we are holding when going to sleep, is a result of our thinking. As he explains, the reason for why people can’t sleep is because they get stuck in the left side of their brains. This is the analytical thinking, the planning and worrying, the thinking about what needs to get done and isn’t finished (Hippensteel, 2022). To change this, we have to shift our focus towards right-brain thinking. This is the creative, imaginative, and artistic thinking. We could do this by travelling in our mind to an imagined ideal place of relaxation. By shifting our attention to being in this imaginary perfect and tranquil place, we relax and focus on healing our body and moving towards our desired futures (Hippensteel, 2022).
Trigger point work and self-myofascial release
Joe also recommends doing additional trigger point massage on the muscles you’re stretching to tamp down the tension, stimulate blood flow and help loosen knots and tightness (Hippensteel, 2022). This can be done during or after the stretching. When using a trigger point approach, Joe recommends finding the sore spot and holding the pressure there, to a pain level of up to seven or eight. Then wait for the pain and sensations to calm down, after which to increase the pressure again. This ultimately results in a melting down of the pain and tightness up until a point where our range of motion is restored again (Hippensteel, 2022).
This practice of trigger point work is also called Self-myofascial release. This is ‘a self-massage technique where you apply pressure on different muscles in order to release tension and improve range of movement and muscle performance. “Myo” is the Greek word for Muscle and “Fascia” is a thin, tough, elastic type of connective tissue that wraps most structures within the human body, including muscle’ (Williams, 2016). Fascia is comprised of collagen fibers tightly packed together in a parallel pattern and is abundant throughout our bodies linking muscles together and providing support, stability and shape. ‘Fascia resides in a gel-like material, called “ground substance” or “extra fibrillar matrix” that provides cushioning. The soft fascia tissue can become restricted due to overuse, which results in pain, muscle tension and diminished blood flow’ (Williams, 2016). Due to overtraining, poor posture, heavy and strenuous exercises, fascia can experience micro-trauma. This results in a tightening and of the fascia tissue and reduced flexibility. ‘What ends up happening is that micro-tears in the fascia will form and if these tears don’t heal properly, the fascia tissue ends up stuck together. This is a condition known as an “adhesion”’ (Williams, 2016). This also makes the before mentioned “ground substance” to solidify and therefore less elastic.
These damages to the myofascia are know as restricted tissue barriers and/or trigger points. With the fascia becoming tighter, it starts to develop adhesions and the underlying muscles movement will be restricted. Consequently, we will experience reduced flexibility, reduced range of motion and muscle aches and pains. This can also restrict nerves and blood vessels with reduced neuromuscular efficiency (connection between the brain and muscles) as a result. Furthermore, this increased tightness in the myofascia can result in blood supply issues to the muscles. In other words, it will inhibit the natural performance and functioning of our muscles. By means of putting pressure on the the sore and restricted areas, tension will slowly release and the body will slowly and gradually be restored to its natural state. ‘The sustained pressure brought about through self-myofascial release helps to break down the adhesions in your fascia, which results in softer, more flexible, fascia tissue. This is what improves your muscle flexibility and movement’ (Williams, 2016).
‘At its most basic, a trigger point is just a tender spot or knot in a muscle’ (Finn, 2020). ‘Trigger points are aggravated spots in fascia tissue with substantial swellings in small bands of muscle fibers’ (Williams, 2016). Donnely et. al. have defined trigger points as ‘tiny contraction knots that develop in the muscle due to overwork or injury’. The particular muscle fiber that is doing all of this contracting is the sarcomere, a microscopic unit in the muscle. ‘When the two parts of sarcomere come together to interlock it causes an extremely minute contraction. If a million sarcomere interlocked in your muscle, it might cause a slight twitch. Normally, sarcomeres act as pumps in the body, as the muscle works these microscopic fibers contract and relax to help in blood circulation. Trigger points occur when overstimulated sarcomeres are unable to release from an interlocked state’ (Williams, 2016). This process results in a lack of oxygen at that particular point in the muscle while a built-up of metabolisms irritate the trigger point, resulting in pain sensations from the affected fibers. The tricky part is however, that these trigger points typically send out referred pain. This basically means that they send pain to another part of the body. Then, instead of paying attention to the trigger point, we pay attention to treating the area of the body where the pain is felt. Dr. Janet Travell and David Simons used the term trigger point to describe certain clinical findings that had the following criteria (Travell and Simons, 1996):
The pain cannot be explained by traditional exploration and neurological examination;
The pain is related to a point in the fascia, discrete and not caused by any local trauma, infection, degeneration, etc;
The point can be seen and felt as a nodule or band in the muscle and upon stimulation will cause a twitch response;
The pain radiates in a distribution typical of the specific muscle where the trigger point is found.
Their ‘Trigger Point Flipcharts’ offers a great resource for finding the right spots to work in order to cure pain at a different location in the body. We can then use a foam roller, trigger point massage ball or pen, and start working the X-spots as indicated in the ‘Trigger Point Flipcharts’. It absolutely works miracles, and is very much worth the try when suffering from chronic pains. What we do by applying pressure on these points – know as ischemic compression and massage – is building up the pressure more until release. That then stimulates blood flow which then helps breaking up the adhesion and release compression and tension. Chase Williams, author of the ‘The Foam Roller Bible’ finds foam rollers the best aid available releasing pressure from trigger points. ‘Myofascial massage works out kinks in your myofascia tissue (if you will) and it is those adhesions that actually cause the majority of health issues relating to poor blood flow, including tired and sore muscles and common aches and pains’ (Williams, 2016).
A child’s abilities
As children, we can do everything. We can run, jump, bend, climb, whatever. I still remember a time in my life when I wasn’t regularly exercising and witnessing a child playing and running around tireless. I remember thinking, ‘if that’d be me running around like that now, I’d be out of breath’. The same is true for a child’s flexibility. They can do much more with their bodies then we can, as adults. Through life, repetitive movements, bad habits, poor posture, and insufficient exercise and movement, we simply lose our ability to fully move. What we do not use, we lose. The essence of what Joe Hippensteel teaches, is to bring us back to our natural abilities we once had as a child. Flexibility is not a miraculous ability, only gifted to the few. No. Once, we all were flexible as children. This is something that with the right practice, structure, and dedication we can all come back to. Since my first talk with Joe, asking him to join me for an interview exactly ten days ago, I’ve been stretching every day. It has been a miracle, nothing less the progress I’ve physically experienced by a mere focused and durational approach to stretching.
A miracle, and a mind shift
For over 12 years, I’ve had issues with tension and pain in my right shoulder. I’ve been to physiotherapists, kinesiologists, masseuses and more. Nothing really helped. The tension and pain always came back. What I realized now, is exactly that. It’s tension! Since my first talk with Joe ten days ago, I’ve started stretching my shoulders. As he had explained in a video I’d seen somewhere, getting your shoulder extended to 120 degrees will alleviate all pain. That’s the natural state we’re able to achieve as a child. Inspired by this, I got to work. I’m amazed to write, that last night, since I don’t know how many years, I was able to lie comfortably on my belly, with my arms to the side without any tension. For a long time, I had been sleeping with my head on my left arm, as laying it lower was impossible due to tightness in my shoulders and neck. Obviously, I’m just getting started with stretching, and there still is a long way to go. But these results in such a short time are truly miraculous for me. Especially, as for long I believed this was merely a part of getting older, and the consequence of some unfortunate strain sometime in the distant past. I learnt now that this is reversable, and that I can go back to that child-like flexibility.
Not only did this make my body more open, and helped soreness reduce, and sometimes completely go away, also it completely shifted my mind with regard to what’s possible. As Joe had beautifully illustrated during our talk, ‘[i]f you’re locked into what [someone else’s] limits are, you’re not able to expand your physical capabilities because you’re locked in mentally’ (Hippensteel, 2022). I was locked in mentally, as I believed this shoulder problem was a given, that I simply had to live with. Seeing these prompt and vivid improvements has showed me otherwise.
Image: copyright Getty Images.
To learn about stretching I have talked to Joe Hippensteel, a man who has dedicated his life and work to training, stretching, and overall, the physical and mental work necessary for ultimate human performance. Building on decades of personal experience, Joe shared with me the ins and outs of a human body reset through stretching and tension release. This talk was extremely educational and inspirational to me. I’ve learnt a lot. I gained new insights about tension, and especially, about letting go.
Next to that, Joe helped me alleviate over 12 years of tension in my right shoulder. After applying his techniques for only a mere 9 days, I was able to sleep in a way I hadn’t been able to due to tension in my neck and right shoulder since over a dozen years. Joe is an expert in stretching and advanced physical and mental training methods and walks the talk.
I learnt about Joe before I started this 39 Ideas for Life project when I read about him in David Goggins’ book, ‘Can’t Hurt Me’. After years of navy SEAL trainings, 3 hell weeks, a whole string of ultra-marathons and triathlons and a world-record for 4030 pullups in under 17 hours, David Goggins found himself with an enormous knot on the back of his head, completely tight. No doctors nor regular healthcare and healing did anything for him. It was Joe Hippensteel who brought him back to life through stretching. And this is but one example of the amazing work and insights of Joe.
In case you have any tightness in your body, in whichever place, you’ll do good to make sure to watch to this talk. Enjoy, and loosen up!
Website of Joe Hippensteel’s company: https://www.ultimatehumanperformance.com
Upcoming seminars by Joe and his partner Mimi Ney: https://www.ultimatehumanperformance.com/seminars
Dawson S, Biga L,, Harwell A, Hopkins R, Kaufmann J, LeMaster J, Matern P, et al., 2021, Anatomy and Physiology. https://open.oregonstate.education/aandp/
Donnelly, Joseph, et. Al., 2019, Myofascial Pain and Dysfunction: The Trigger Point Manual.https://amzn.to/3AYva1J
Finn, Richard, 2020, Trigger Point Therapy Made Simple: Serious Pain Relief in 4 Easy Steps.https://amzn.to/34yDA3K
Goggins, David, 2020, Can’t Hurt Me. https://amzn.to/34cIhQw
Liebman, Hollis, 2017, 1,500 Stretches: The Complete Guide to Flexibility and Movement. https://amzn.to/34jdUIP
Quinn, Elizabeth, 2021, Generally Accepted Values for Normal Range of Motion (ROM) in Joints. https://www.verywellhealth.com/what-is-normal-range-of-motion-in-a-joint-3120361, accessed on 3 February, 2022.
Starrett , Kelly and Glen Cordoza, 2015, Becoming a Supple Leopard: The Ultimate Guide to Resolving Pain, Preventing Injury, and Optimizing Athletic Performance. https://amzn.to/3HrF5zs
Travell, Janet and David Simons, 1996, Trigger Point Flip Charts. https://amzn.to/34CwJGs
Tuffelmire, Dana, 2022, Why Is Breathing Important During Stretching? TheNest.com https://woman.thenest.com/breathing-important-during-stretching-18639.html, accessed on 4 February, 2022.
Warton, Jim and Phil Warton, 1996, The Wartons’ Stretch Book: Featuring the Breakthrough Method of Active-Isolated Stretching. https://amzn.to/3urYhcH
Williams, Chase, 2016, The Foam Roller Bible: Foam Rolling Self Massage, Trigger Point Therapy & Stretching. https://amzn.to/3AZfPhp