Unarmed Strike: At 1st level, a monk gains Improved Unarmed Strike as a bonus feat. A monk’s attacks may be with either fist interchangeably or even from elbows, knees, and feet. This means that a monk may even make unarmed strikes with her hands full. There is no such thing as an off-hand attack for a monk striking unarmed. A monk may thus apply her full Strength bonus on damage rolls for all her unarmed strikes.
3.5SED說 (如上)
從monk的徒手攻擊是拳打,肘擊,膝頂...的組合技的關點來說
你整個人算一件武器,那你怎麼用一件武器進行雙武器戰鬥?
除非你手上拿了件武器,然後用身體其他部份進行monk的徒手攻擊
所以,不是monk的徒手攻擊不能配雙武器戰鬥相關專長使用
而是你不能 "只" 用monk的徒手攻擊當作你有兩把武器而發動雙武器戰鬥相關專長的效果