How do I know if the soccer shoes in a store are approved by USSF? The location of the lead cleat on the new styles of shoes appears dangerous.
When it comes to the cleats on the footboll (soccer) players' shoes, it's generally up to the referee to decide whether they are approved or not. You will not get any help from within the Laws of the Game.
According to IFAB (FIFA) - Laws of the Game 2019/20:
Law 04 The Players' Equipment
A player must not use equipment or wear anything that is dangerous.
2) Compulsory equipment
According to Modifications by US Youth Soccer:
Law 4: Player's Equipment
Cleats are recommended but not required.
No baseball cleats with a “toe cleat” or metal spikes are allowed.
According to an answer by USSF in Ask A Soccer Referee
USSF answer (March 26, 2008)
It is illegal to play soccer in football or baseball cleats of the traditional sort with toe cleats, even if the toe cleats are cut off. There is no documentation on this, other than the requirement that players’ equipment must be safe for them and all participants. Traditional football and baseball cleats are unsafe and not permitted in soccer games. In any event, the final decision rests on the opinion of the referee.