Normal Range of Motion (ROM), based on what?

When we consider health, there are many normative values: 12-15 breaths/ minute, 120/80 for blood pressure, 20/20 eyesight, a resting heart rate of 60 bpm. Further, if you get your blood drawn for a standard blood panel, there is a range of “normal” for multiple markers.  

Sadly, in the world of movement, there is no agreed-upon “normal.” The closest that we get is Range of Motion. There is a normal ROM for every joint in the body. Measure elbow flexion, and you can quickly look at a chart/table to see if your elbow flexion is considered “normal.” Since my first day on the Southwest Missouri State University campus in 1996, I have held these norms as written in stone. Why would I question them? Every book I had that centered around movement (from my anatomy classes to my biomechanics classes to my athletic training classes to my PE classes) all had some ROM reference material included. Fast forward 5 years to today (I avoided every math class like the plague and just barely squeezed by – the only time I was ever proud of a C). Every day I still look at ROM and gauge it based on the established normals.  

But, here is a question- where did those normals come from?

In the words of my 9-year-old, how do you even “search that up” on Google? I have always assumed that those ROM values considered normal were established in a lab by a lot of brilliant people. My world was rocked as I dove into this quest to find the roots of not just ROM normative values, but measuring ROM. Do you know where that goniometer that you use to measure ROM developed and why? (now you are really wondering, aren’t you…)

The FIRST reference to normal motions at a joint THAT I HAVE FOUND is from an Anatomy text written in 1889. One-Hundred and thirty years ago. I will go into more detail in a moment. Still, at this point, it is fascinating to note that the goniometer wasn’t introduced to the world until 1916. So, question #1 in my mind was how did an anatomist in 1889 measure the ROM he called “normal”?

The seminal texts and articles on normal motion (it wasn’t called ROM at the time) aren’t quite as pristine as what I had on the pedestal of my mind. In fact, the roots of these ROM normative values begin from a much darker place. The earliest studies involved grotesquely injured soldiers from WWI, polio patients, and contraptions build to isolate movement that tested the limits of an individual’s pain capacity. On top of that, by today’s standards, there were some very questionable scientific processes.   

In 1889 Professor Alexander Macalister published the text for which he is the most known for, “Text-book of Human Anatomy.” He was an anatomist at Cambridge University, and in addition to this text on human anatomy, he published other works on the anatomy of humans and animals. Mainly, he spent his life working with both animal and human cadavers and teaching. In the Preface, this is one of his opinion remarks:

The Anatomy of Man is a study of averages, and it is often hard to draw the line between what may be regarded as normal and that which is abnormal. I have endeavored in each case to decide in accordance with what I have seen and noted during the past thirty years of my dissecting-room experience.”

There are no references, nor is there a bibliography for this work. The assumption I am left with is that he is basing his “normal” off of his experience with cadaveric joints. Personally, I have yet to work with any cadavers.  

In 1917 the Balneologist (Balneology is the study of therapeutic bathing and medicinal springs) Dr. Fortiscue Fox shared a story of a trip he made to Paris where he was first introduced to the newest contraption at the time – the dynamo-ergograph. A French physiology professor by the name of Camus created a series of measuring devices to “graphically record the movement and power of weakened limbs.” In this paper, he states, “I do not profess that they are accurate to the degree of perfection, but they are the best we have come across.” Interesting to note that today, the on-the-ground clinician is left with a tool that is almost identical to the device that was “the best we have come across” 102 years ago.

In an article from 1932, the researchers looked to establish what “normal” hip ABDuction and Lateral Rotation was. This appears to be the first study where the measured motion was isolated. In a previous study with human subjects, lateral flexion of the trunk was allowed to occur, which led to abduction measurements considerably higher than what was found in the1932 study where the trunk position was stabilized. The authors referenced 3-4 previous articles that also shared hip abduction ranges that were considerably higher than what their research found. These cited articles gathered their “normal” ranges of motion from “ligamentous, anatomical preparations” of cadavers. Needless to say, living subjects will have less motion at any joint than corpses because of many factors, most notably a functioning Central Nervous System. In this 1932 article, the average abduction ROM was 36˚. In a 1991 study looking at hip abduction in a similar population, using a completely different set of methods and measurements, the authors documented “normal” hip abduction as 44˚ (with a standard deviation of 11˚, or 25%). The 1991 study does not note what occurred at the trunk, just that “the opposite side was kept straight.” Considering the studies were separated by 55 years, I was surprised to see that the ROM norms only differed by 8 degrees. 

The 1889 Anatomy text I referenced above mentioned that normal knee flexion was 135˚, and the 1991 study from the previous paragraph noted normal knee flexion as 132˚. Here we see a gap of 102 years being within 3˚. More impressive is that one was done on cadaveric knees, and the other on living subjects.  

At this point, you are probably wondering what the whole point of this is? In the past 130 years, range of motion “norms” have stayed relatively consistent regardless of how we have measured them and on whom we have taken the measure from (live subjects or cadavers). Is that a tip of the hat to the forefathers of ROM measurement for doing such a great job with their limited data collection capabilities, or an indictment on today’s researchers that they can’t do better than what 130-year-old technology produced? Your call. At the end of the day, if I measure knee flexion as 128˚ is that normal? Better question, does isolated ROM on a table matter to the person that lives their life on two feet? If a person has “normal” knee ROM but cannot squat below parallel, are they “normal” because they hit an arbitrary number in isolation on the table?

As part of trying to find some answers to the history of ROM testing, I reached out to the living encyclopedia of the history of physical culture, Dr. Ed Thomas. We spoke for about 2 hours on the topic, and I took 5 pages of notes. Pure gold. He pointed out a couple of things that I hadn’t considered.

  1. As a country, we don’t have a long history of physical culture/restorative practices that many other cultures have. This means everything embedded in our roots is a borrowed interpretation of practices from other cultures. What has happened is in the need/rush to create, many things were bastardized. I immediately flashed back to the origins of the goniometer and why it was developed. It was created in France in the early 1900s as a tool to show improvements in ROM AND strength. The first goniometers had COG wheels to provide some resistance. This information primarily gathered to share with patients with the intent of improving their mood/outlook on their condition (many of the initial patients were wounded soldiers). ROM/Strength measures were used not to provide “normal” parameters but as a tool to show progress and improve the psychological side of the care of the patients. I’d say we have bastardized that just a little…
  2. We can’t compare humans today in this country to anything more than 10 years old. Why? The decline in the physical capacity associated with the lack of physical culture and the shift to us as a population being sedentary. Dr. Thomas traces this back to the shift away from physical culture to the emphasis on sport culture that occurred after WW2. As a country, we physically are inferior to our parents and our grandparents at the same age. In the 1950s, there was a shift from a global ability to move to a more isolated approach to fitness (the golden age of bodybuilding and the West Coast cultural shift that began to spread). Again I flash to the research that established what was considered “normal” ROM. Much of this research began in the 1950s and continued into the 1970s. Research from the 1980s through the 2000s have all been based on those initial studies in the 1930s-1950s. Normal isn’t a term we can use, because we don’t know what normal is any more.

At this point, I decided my quest to find how “normal” was established was off-base. Yes, we do need to document ROM following an injury/surgery to show insurance and the physician’s improvement. Still, I think my take away was that this should also be used as a tool to assist the psychological condition of the patient. The insurance and MD side of that is secondary to the patient. However, chasing “normal” might be misspent time. Instead, we should go after “optimal” for the patient. How do we do that? By balancing the global ability of the patient/individual and getting back to paying attention to what every human should be able to do to be considered a human. Crap, how do we do that? Simple, but I’m not ready to share that piece of information yet. I will say it has nothing to do with getting back to moving like a baby or how our primitive ancestors lived.

Why not?  Especially since those two areas are current fitness fads making their founders some pretty good $$$.  Sadly, there is one small piece of information that has been omitted from their marketing campaigns.  It’s kind of an industry secret, the elephant in the room everyone is trying to keep hidden behind the curtains.  We are not the same as babies nor are we the same as our primitive ancestors.  Likely, because of the world we live in and our amazing ability to adapt, we will never be able to access that ability again (without SIGNIFICANT lifestyle and cultural changes). You shouldn’t try to move like a baby and you shouldn’t act like a primitive – unless you are willing to spend the bulk of your day drooling on yourself and stalking your dinner (that you then kill with your atlatl or another primitive weapon).  Don’t assume that today we are better off in totality than our primitive ancestors.  While I don’t think anyone would argue that there are many areas where we are much better today than we were even 20 years ago (medicine, technology, wastewater management, water management) we do need to acknowledge that those advancements came at a cost (self-sustainability, strength, movement ability, food source purity, etc).

We have changed, and we have changed our world.  What we can do is use that information as a reference to guide us in our quest to be the most optimal we can be today in today’s world.  Hopefully, we can shift the balance for our children/grandchildren. We cannot fix all of our current movement problems/adaptations. Those issues began long before any of us had any say.  However, what we do today can prevent our children and grandchildren from suffering the same fate of movement degrading. Our kids don’t listen to what we say (at least mine doesn’t), but they do imitate everything that we do. The lifestyle they grow up in will be what they consider “normal” for their whole life – just keep that in mind.

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