This post summarizes research by Jason Baer, Anita Vasavada, and Rajal Cohen, “Neck posture is influenced by anticipation of stepping,” published in Human Movement Science in 2019. It was originally published at Alexander &.
A common reason people study the Alexander Technique is to improve their posture. Many students are therefore confused and even frustrated in lessons when their Alexander teacher seems to change the subject. Rather than telling a student the correct way to stand or defining proper alignment, a teacher will often coach a student to resist the urge to anticipate a movement—such as beginning to walk or sitting down. They will often add that this practice is a key Alexander skill called inhibition. What does any of this have to do with posture?
Helpfully, inhibition (or inhibitory control) is also a key concept in cognitive psychology and neuroscience and there is a growing body of research showing how cognition—how we think—links up with posture and movement. A case in point is a new study published in Human Movement Science from Jason Baer and Rajal Cohen of the Mind in Movement Lab at the University of Idaho and Anita Vasavada of Washington State University and partly inspired by the Alexander Technique.
What Can You Learn from Carrying a Tray?
On the surface, the study seems to be about the extremely mundane task of carrying a tray. The researchers had 45 healthy individuals, ages 18–29, walk two meters carrying a tray and then put it down at elbow height. Then they made the task harder by having them walk two meters carrying a tray and put it on a small box low to the ground. Then they made it even more challenging—more “compelling” is the language in the study—by having them carry the tray while keeping a magic marker from rolling around and then putting it down at elbow height. Thrilling stuff!
But the study isn’t really about carrying a tray. The researchers began collecting data 3-seconds before the subjects began walking. So this is really a study of anticipation. It’s about what we do before the thing we’re doing. And the experiment marks the first time scientists have shown a link between problems with posture, anticipating movement, and challenges with inhibitory control.
Forward Head Posture
The researchers were watching subjects walking and carrying trays because they were interested in understanding what is called “forward head posture” (FHP). FHP is a common postural problem. Think of a typical computer user pushing their head toward their computer screen [See Fig. 1].
FHP is bad news. It is linked with increased chronic neck pain, reduced range of motion in the jaw, neck and shoulders, muscle strain in the upper back and shoulders, increased headaches, reduced respiration, and reduced stability and increased risk of falling in older adults.
FHP is often defined as a problem with postural alignment—the idea that ideal human vertical posture “aligns” to a plumb line running from the head to the feet. It’s easy to assume that postural problems are static. People “hold” their heads forward. But what if forward head posture is a dynamic problem? What if forward head posture increases in anticipation of movement?
This is why the researchers used such a simple task as carrying a tray and setting it down. The task needed to be simple so they could watch for subtle changes in posture. They also wanted to be able to make the task more challenging (without changing the basic physical requirements of the task) in order to see if postural changes increased with the perceived difficulty of the about-to-be-performed task.
The researchers tracked their subjects with a 3D motion capture camera system. Motion capture has become famous as a special effects technique in movies over the last twenty years, but the technique is also used in the movement sciences. In this study, the subjects wore small reflective dots at key points in the body [See Fig. 2]. The motion capture system used the location of those dots to determine where the body segments were located, allowing the researchers to analyze changes in the angles of the head, neck, and torso.
The subjects stood quietly for 10-seconds to form a baseline comparison, and then the researchers gave them a 3-second countdown. This allowed the researchers to assess whether movement at any part of the body anticipated the first step.
And what did the researchers find?
The subjects did push their heads forward in anticipation of taking their first step. And the more challenging the anticipated movement—as when they were getting ready to keep the magic marker from rolling about the tray while walking—the more the subjects pushed their heads forward before taking the first step.
Accounting for Individual Differences
Subjects differed in how much they pushed their heads forward. Some pushed their heads forward very little, while others quite a bit. Subjects also had different habitual posture. Some had more chronic head forward posture than others. What accounts for these differences?
The researchers were curious if these differences had anything to do with mindfulness and inhibitory control. It seems likely that someone who is more mindful and has better inhibitory control would be better at not anticipating. Would they also have less forward head posture?
To measure mindfulness, the researchers had the subjects fill out the Mindful Attention Awareness Scale (MAAS). This is a 15-item questionnaire that assesses subjects’ impressions about their own level of self-awareness. It includes such relevant questions as, “I get so focused on the goal I want to achieve that I lose touch with what I’m doing right now to get there.”
Self-report questionnaires have the downside that subjects can intentionally or unintentionally exaggerate their answers—for example, if they want to come across as more mindful than they are. So in addition to the MAAS, the researchers had their subjects take two commonly used tests of inhibitory control.
Inhibitory control is a central element of what scientists call “executive function.” Executive function involves a suite of cognitive skills, including working memory, attentional control, impulse control, and inhibitory control, that allow people to make choices about what they do and don’t do.
Two common ways of testing inhibitory control are the Go/No-Go task and the Stroop task.
In a Go/No-Go task, you sit at a computer screen and every time a letter shows up on the screen you press a key as quickly as possible. After practicing this task for a while, the researchers switch it up. Now, you are supposed to press a key as quickly as possible except when it’s an ‘X’. If the subjects accidentally press the key when there’s an ‘X,’ it’s called a “false alarm” and it represents a failure to inhibit.
In the Stroop task, you start by naming the colors of color swatches out loud. Then you read color words out loud (RED, GREEN, BLUE, etc) printed in black ink. In the final step, you name color words out loud, but there’s a trick: you have to name the color of the printed ink, which is usually different from the word [See Fig. 3]. In this task, you are required to inhibit your well-learned tendency to read words that you see.
The faster you complete the Go/No-Go and Stroop tasks and the fewer false alarms or errors you make, the better your inhibitory control.
What did the researchers find? You’ll remember that when carrying the tray, the subjects anticipated the first step by pushing their heads forward. The more compelling the task, the more they pushed their heads forward.
Some subjects had more habitual head forward posture. Those subjects also scored lower on mindfulness and did worse on the Stroop task.
Interestingly, there was no association between making errors on the Go/No-Go task and habitual FHP. However, subjects who did worse on the Go/No-Go task had a greater tendency to hold their head “extended” relative to the neck (picture pulling your head back into your neck). And the worse they did on Go/No-Go, the more they shortened their necks when anticipating the movement while carrying the tray.
Different Kinds Of Inhibition?
This is the first study to link difficulties with inhibitory control with problems with posture. However, there were differences between the two tests of inhibitory control. Subjects who fared badly on Stroop also had chronic FHP. But subjects who did poorly on Go/No-Go tended to hold their head in an extended position [See Fig. 4]. Go/No-Go was also associated with shortening the neck during anticipation of movement. Why these differences between these two tests of inhibitory control?
The short answer is that we don’t know. The researchers speculate that it might have something to do with the kind of inhibition that each test measures. It turns out that there are different kinds of inhibition!
Go/No-Go is considered a measure of “reactive inhibition,” the kind of inhibition you use when you need to suddenly change course in the middle of an activity. Stroop is more of a test of “proactive inhibition,” the decision to not react before taking part in an action. One possibility is that reactive and proactive inhibition could manifest differently in posture and movement.
Posture, Inhibition, and the Alexander Technique
This study is a great example of how much we can learn about the mind and body from even the most mundane activity. It also helps explain why we approach posture the way we do in Alexander lessons.
It is common to conceive of posture as a static position. If postural problems like forward head posture are also static, then the solution would be to hold our bodies in a different way. And this is what a lot of traditional posture advice has you do—”chin in,” “chest up,” “shoulders back,” “back straight.”
But if postural problems are dynamic—if forward head posture increases in anticipation of movement—then the solution may be found in understanding how we prepare to move. And if problems with posture correlate with difficulties with inhibitory control, then mindfulness practices may be as crucial in improving posture as any kind of posture exercise. And this is at least partly why we spend so much time in Alexander lessons cultivating the skill of inhibition, especially in our most compelling activities. What this study shows us is that when students come for lessons in posture and their Alexander teachers talk about inhibition, their teachers aren’t changing the subject at all.