Here in the West, we model the relationship between our minds and our bodies like this:
The mind, according to this view, is like a little person inside our heads, sitting in the control tower, receiving data from the outside and issuing commands to the body. Questions about dualism aside, what's interesting here is that the mind is in control of the body.
This way of looking at things is useful, but incomplete, because influence runs the other way as well. What we do with our bodies can change how our minds think, feel, and perceive.
It may sound like I'm making some New Age-y claim, but I'm not. I'm just pointing out that specific physical actions, often even small and simple ones, can influence our thoughts, feelings, and perceptions of the world around us.
Dancing makes us feel happy. Bowing makes us feel submissive. Good posture and breathing give us confidence.
Viewed this way, the body becomes an instrument, an input device, for manipulating the mind. Imagine your limbs as joysticks. Move them in a particular pattern (up, up, down, down, left, right, left, right, B, A) and you can unlock entirely new states of consciousness.
This is the power of ritual.