There is a lot of walking going on especially in rural Congo. Getting from one place to another place in Congo usually involves walking. Getting food involves walking. Getting water involves walking. Getting to school involves walking. And getting to a doctor involves a lot of walking.
In most places, like the US, walking is consider healthy. But Congo has too much of a good thing. But it is not the walking that causes problems. It's the lack of nutritious foods. It's the lack of safe water to drink. It's the lack of education and health opportunities.
The lack of transportation or too much is walking is not the problem in many cases.