During monotonous walking, heart beats may involuntarily synchronize with steps. One of the opinions is that walking facilitates the pumping of blood. And it helps to keep the rhythm of not only the heart but also the breath.
Even when walking, instinctive control of muscles, balance and visual automatic observation of obstacles are activated. Of course, it happens that thoughts are so captivating that walking gets out of rhythm, you lose visual control and you may not even notice an obstacle and collide with it. But this is an extreme case.
The need to walk may be due to the need to be in a constant excited state. And this need may be the result of some chronic illness. When immersed in thoughts without movement, without the usual distraction of attention to the outside world, this disease can begin to manifest itself, be felt more acutely. And walking muffles these sensations.
In general, a healthy person should not be afraid to be too calm, should not feel the need for continuous excitement. But the habit of walking when you think is not necessarily a sign of illness. Sometimes this walking really helps – it unloads and helps the heart, synchronizes breathing, sets the rhythm. And it does not allow you to go too deep into yourself, it keeps minimal muscle control.