A force transmission mechanism includes a force adjuster that receives a driving force and that is configured to change a force transmission efficiency, and also includes a driving member that is configured to connect an end effector and the force adjuster via a joint section and transmit the driving force. The force adjuster converts the driving force into a linear force via a rotational force, and increases the conversion efficiency from the driving force to the linear force such that an amount of increase in the force transmission efficiency increases with increasing displacement amount of the driving member when the driving member is displaced in accordance with flexing or curving of the joint section.
