i was looking at pictures of phalanx and they where all holding the spear with their right hand and the shield with the left, so what would happen if someone was left handed? where they ambidextrous? i'm left handed and i'm pretty uncoordinated with my right arm.
The main comment on [this thread] (http://www.reddit.com/r/AskHistorians/comments/23aiwx/how_important_was_left_vs_right_handedness_in/) from a couple of weeks ago may help with your question.