Wouldn't that be the worst attack with a pretty bad weapon for fighting someone in any kind of armor?
Heavy-bladed swords such as the falchion or later dussage (from which the cutlass comes from) could still break collar bones and disable the shoulder I think and it's possible a normal sword's cut could do the same.
The most common battlefield weapon at the time was the poll axe and the halberd. These would kill people inside 'plate' armour. Possibly the best suit of armour of the period housed the Duke of Burgundy and he was hacked to death by a halberd(s) at the Battle of Nancy after being dragged from his horse.
On a tangent I think it brings home just how hard you were to kill when wearing white harness (plate). If you could stay mobile you were effectively invulnerable to a single handed sword or axe. Sword users would grip the blade as well as the grip to turn the sword into a short two-handed spear and try and stab the user in the joints. Even so, these joints were protected by chain and it took a lot of stabbing to get through, no easy task when the other guy is trying to stab you back.