Any shift in self changes how we feel or how we perceive things or what happens inside us. A small practice produces a small change, often lasting only during the practice or for a while afterward. Not a permanent shift, but a change nonetheless.
If you do a variety of practices over time, your body experiences a variety of small temporary shifts. Your body learns repeatedly that shift is possible. Shifting your experience through practice makes you more flexible, allowing your body to accept a larger shift when circumstances allow one to arise.
Also, healing shifts tend to be accompanied or driven by shifts in cognitive understanding. The small practices we do every day often gift us with small insights, or glimpses into a larger understanding that we can sense but not quite reach. The accumulation of these smaller experiences of insight can support the meaning-making elements of a larger shift, when circumstances allow for that larger shift to be possible.