The base position is the position of the body that we should have before a throw (and try to maintain it when displacing). It’s different depending on where the ball is, but it has common components. The basic position should facilitate all technical gestures.
Hands slightly above the head, slightly forward to try to catch the ball and absorb the impacts. The body should be in a natural, upright position. Knees should be slightly bent for far throws. The heel may be slightly raised if this does not unbalance or shift our body forward.
Goalkeepers should be comfortable in the basic position, it cannot be a forced position.