The phrase "just a sprain" may grossly understate the impairment such an injury imparts. Why might a grade ONE ankle sprain cause long term impairment?
Let's revisit that inversion sprain.
There are two injuries here, really. Tension on the CF ligament and compression on the talus.
Even if the CFL is not torn, you can get damage to the proprioceptive nerve fibers in it and get a sense of unsteadiness despite being intact as well as post traumatic arthrosis (arthritis) of the tibio-talar joint
For the interested student only: An inversion force to the ankle can really injure the bone or the ligament. Which gets injured actually depends on the rate of speed of loading, owing to the bone's so-call visco-elastic properties:
Which is worse? And (of course) WHY?