A conventional muscular strength assisting instrument may give assisting force to prevent an action of a user who is trying to evade a dangerous situation when the user is in such a dangerous situation. A muscular strength assisting instrument comprises: an assisting unit that assists muscular strength of a user by using assisting force due to extension or contraction； a detection unit that detects a predetermined dangerous situation； and a control unit that adjusts the assisting force of the assisting unit when the dangerous situation is detected by the detection unit.
