Cognitive dissonance, a possible risk factor for neck and low back pain: study
According to a new study, the emotional distress of mental dissonance—receiving knowledge that contradicts how we act or what we think—could contribute to increased stress on the neck and lower back during lifting and lowering tasks. When study participants were told they were performing poorly in a precision descent experiment in the lab, after initially being told they were doing well, their movements were associated with increased load on the vertebrae of the lower back. neck and lower back. The results showed that the higher the cognitive dissonance score, the higher the degree of load on the upper and lower parts of the spine.
The finding suggests that cognitive dissonance may be a previously unrecognized risk factor for neck and low back pain, which could have implications for workplace hazard prevention, the researchers say. “This increased load on the spine occurred in a single condition with a fairly light load; you can imagine what this would look like with more complex tasks or higher loads,” said lead author William Marras, executive director of the Research Institute. of The Ohio State Vertebral Column. University. “Basically, the study scratched the surface of showing that there is something to this.”
The research was recently published in the journal Ergonomics. Marras’ lab has been studying daily life and occupational forces on the spine for decades. About 20 years ago, he discovered that psychological stress could influence the biomechanics of the spine, using a study design that involved having a fake discussion with a graduate student in front of research participants. “We found that in certain personality types, spinal loads were increased by up to 35%,” Marras said. “We ended up finding that when you’re under that kind of psychosocial stress, what you tend to do is what we call coactivating the muscles in your core. It creates this push and pull in the muscles because you’re always tense.” That mind-body connection, we decided to look at the way people think and, with cognitive dissonance, when people are disturbed by their thoughts.”
Seventeen research participants, nine men and eight women aged 19 to 44, completed three phases of an experiment in which they placed a lightweight box inside a square on a surface that moved left and right, up and down. After a brief practice run, the researchers gave almost exclusively positive feedback during the first of two 45-minute test blocks. During the second, the feedback increasingly suggested that the participants were performing unsatisfactorily. To arrive at a cognitive dissonance score for each participant, changes during the experiment in blood pressure and heart rate variability were combined with responses to two questionnaires that assessed levels of discomfort, as well as positive and negative affect. : feeling strong and inspired versus anxious and ashamed.
Wearable sensors and motion capture technology were used to detect peak spinal loads in the neck and lower back: both compression of the vertebrae and vertebral movement, or shear, from side to side (lateral) and forward and back (A/P). Statistical modeling showed that, on average, peak spinal loads on the cervical vertebrae in the neck were 11.1% higher in compression, 9.4% higher in A/P shear, and 19.3% higher. highs in lateral shear during the negative feedback test block compared to baseline measurements from the practice run. Peak loading in the lumbar region of the lower back, an area that bears the majority of any spinal load, increased by 1.7% in compression and 2.2% in shear during the final test block.
“Part of the motivation here was to see if cognitive dissonance can manifest in more than just the lower back — we thought we’d find it there, but we didn’t know what we’d find in the neck. We found a pretty strong response in the neck,” he said. Marras, a professor of integrated systems engineering with academic appointments from the School of Medicine in neurosurgery, orthopedics, and physical medicine and rehabilitation. “Our shear tolerance is much, much less than compression, so that’s why it’s important,” he said. “A small percentage of the load isn’t a big deal for once. But think about when you’re working day in and day out, and you’re in a job where you’re doing this 40-hour week, that could be significant, and be the difference between a disorder and not having a disorder.
Marras is also the principal investigator in a federally funded, multi-institutional clinical trial evaluating different treatments for low back pain ranging from medication to exercise to cognitive behavioral therapy. “We’re trying to unravel this onion and understand all the different things that affect spinal disorders because it’s very, very complex,” he said. “Just like the whole system has to be right for a car to work right, we’re learning that’s the way it is with the spine. You might be in good physical shape, but if you’re not thinking correctly or properly, or have all these mental irregularities , like cognitive dissonance, that will affect the system. And until you get it right, you won’t be right. We’re looking at causal pathways. And now we can say cognitive dissonance plays a role and that’s how it works.”
This research was supported by internal funding from the Spine Research Institute. Co-authors included first author Eric Weston, a former embedded systems engineering graduate student at Ohio State; Afton Hassett of the University of Michigan; and Safdar Khan and Tristan Weaver from Ohio State.