Opponent: You can't move through a square occupied by an opponent unless the opponent is helpless.
Helpless: A helpless character is paralyzed, held, bound, sleeping, unconscious, or otherwise completely at an opponent's mercy.
这里有个很微妙的Held，理论上说，因为后面还有个bound，而因为擒抱而被pinned之后是可以五花大绑的，所以我趋向于认为被pinned的对手，你可以穿越。
另外根据抓住别人一根指头也算擒抱这个条件，擒抱中的对手你肯定是不能穿越的。
至于说pinned的角色的行动力：
Pinned: A pinned creature is tightly bound and can take few actions. A pinned creature cannot move and is denied its Dexterity bonus..A pinned character also takes an additional –4 penalty to his Armor Class. A pinned creature is limited in the actions that it can take. A pinned creature can always attempt to free itself, usually through a combat maneuver check or Escape Artist check. A pinned creature can take verbal and mental actions, but cannot cast any spells that require a somatic or material component. A pinned character who attempts to cast a spell or use a spell-like ability must make a concentration check (DC 10 + grappler's CMB + spell level) or lose the spell. Pinned is a more severe version of grappled, and their effects do not stack.
虽然这里没有明说你可以进行何种行动，但参照姿势和材料法术要求你至少空出一只手来的条件，我认为被pinned可以算作连手都拿不出来。
