Figure 3:

Original potential U(Q) shows two states (Left, Right) separated by a barrier, which decreases when a force is applied. The rate constant k_L→R depends exponentially on the height of the barrier (vertical dashed line), which is the difference in energy between Q^‡ and Q_L. For small forces, the positions of Q_L, Q_R, and Q^‡ do not move much, but it is evident here that this force shifts the position of the transition state. In addition to the barrier, the applied force also decreases the energy difference between the two states, ΔE_RL.