How did the hoplite phalanx truly fight during the Classical period?

by CardR100

I’ve seen two competing theories, one where the men stab at each other with their spears and another where the two phalanges clash and push together (the Othismos). How would the latter not cause the front ranks in both armies to be crushed to death by the men behind them? For which theory is there currently more evidence?

Thank you in advance

voyeur324