We all know the overarm vs underarm debate of how hoplites hold their spears. In comparison, no such question has been raised concerning pike.
We all take for granted that Macedonian-style pikemen hold their pikes at waist level. Given their shield strapped onto an arm, I do not see any viable alternative to that. I'm however yet to see a graphical evidence of how pikemen looked like in Ancient times. All we have are description in ancient texts, which might be sometimes ambiguous.
Fast forward to Renaissance, where pikes again were widely used on battlefields. We know that Renaissance pikemen didn't carry shield, which could arguably be attributed to the advance of armour making. I saw some pike drill manuals and actually, in many cases, pike was hold at shoulder level, like in the following picture.
While it looks awkward at first, it is actually much superior to the normal waist-level holding stance, since the pike (which is very heavy) is properly locked onto user's body. Such stance will result in much less exhaustion in any prolonged period of time.
What do you think about this difference and if it had any impact on tactical use of pike on battlefield?