The science behind why shoulder stretches feel so good
We roll our shoulders and stretch our backs because it feels relaxing, refreshing and maybe even rejuvenating. But why is that? In healthy adults, the stretch leads to a quick drop in blood pressure, researchers have found. And the body’s reaction to the movement may explain why we feel calmer after we stretch.
Physicians at the University of Minnesota speculate that stretching the upper back muscles triggers a reflex through the parasympathetic nervous system, which may explain the feeling of relaxation. Last month, the researchers published some of their findings in a small study for the scientific journal Physiological Reports. It appears that the response in blood pressure and heart rate may explain “this pleasant sensation,” said Jorge L. Reyes, a cardiovascular disease fellow at the University of Minnesota and the lead author of the study.
(snip)
The participants sat in a chair with their arms resting on their legs. Then a physician instructed them to roll their shoulders to their ears, lean backward slightly and flex their upper back for 10 to 15 seconds without holding their breath. When participants stretched their back, the researchers saw a “fairly dramatic” drop in blood pressure, Reyes said. Often, when our blood pressure falls, our heart rate picks up to maintain blood flow, Benditt said. (This happens when we stand up, as gravity pulls blood to the legs.)
But, as participants stretched their backs, their heart rates didn’t rise as much as expected. That combination — a drop in blood pressure without a rise in heart rate — may be because of a response in the parasympathetic nervous system and could explain why stretching feels relaxing for many people, Reyes said.
(snip)
Next, researchers need to determine the exact mechanism that causes the apparent drop in blood pressure, Joyner said. Physicians know signals from nerves in the muscles to the brain can influence someone’s blood pressure and heart rate, he said. Then they need to find out whether this phenomenon happens in everyone — not just young adults referred to the clinic for fainting or lightheadedness.
More..
https://archive.ph/BCqh2#selection-597.0-633.313