Efficient movement minimizes the metabolic cost of achieving a task. In running, this means minimizing ground contact time, maximizing elastic energy return, and reducing vertical oscillation (energy wasted moving up and down).
Elite distance runners share a characteristic pattern: short ground contact, slight forward lean, cadence around 180 steps/minute, minimal heel strike. These are consequences of efficiency, not causes — you don't get efficient by copying the pattern; you get the pattern by becoming efficient.
The intervention that works: remove restriction (bad shoes, weak hips, tight calves) and let the body find efficiency on its own.