the macedonian phalanx could also lose its cohesion without proper coordination or while moving through broken terrain; doing so could create gaps between individual blocks/syntagmata, or could prevent a solid front within those sub-units as well, causing other sections of the line to bunch up. in this event, as in the battles of cynoscephalae and pydna, the phalanx became vulnerable to attacks by more flexible units—such as roman legionary centuries, which were able to avoid the sarissae and engage in hand-to-hand combat with the phalangites.