Coach Ken Eriksen describes how hitters should be approaching and touching first base in the proper position and location.
It’s important for players to hit the correct part of first base with their foot as they’re running to base. Even as the hitter is running, she should be plotting her footwork to hit the base as quickly as possible. Only her toe needs to hit the base in order to be safe. As she touches the base, she should keep her shoulders and legs low and loaded so she doesn’t stand up and lose momentum.
As a safety measure, teach your hitters to take a short step to reach first base instead of lunging with a large step; This will prevent potential injuries from overextending the leg.