Rolling your shoulders or stretching your back often feels unexpectedly soothing. Now, researchers may know why.

A team from the University of Minnesota has discovered that this simple motion can cause a noticeable drop in blood pressure — and that reaction may be the reason for the calm, pleasant sensation many people experience.

In their small study, published in Physiological Reports, 24 healthy adults were asked to lift their shoulders toward their ears, lean back slightly, and flex their upper backs for about 10 to 15 seconds.

During this brief stretch, participants showed a "dramatic" fall in blood pressure, yet their heart rates did not rise as expected.

This unusual combination suggests that stretching activates a reflex through the parasympathetic nervous system, which helps the body relax.

Lead author Reyes speculated that the response may be a spinal reflex triggered by upper-back muscles. Senior author David Benditt said "small brick in the big wall of understanding how the human body works." Although the study was small, the findings point to intriguing implications.

If this reflex truly lowers blood pressure, scientists may eventually use similar mechanisms to help people manage stress or mild hypertension. As Harvard researcher Stephen Juraschek noted, "Even a simple stretch might influence cardiovascular regulation."