This ankle dorsiflexion machine can definitely help to strengthen the ankle muscles and support the arches, but it is not the most functional ankle exercise. (best-leg-exercises.com)
A loss of dorsiflexion creates an inability to actively dissipate force in the lower extremity which limits performance, and can lead to problems locally and up the chain (knees and lower back) as the force must go somewhere. (sportstarsmag.com)