Final answer:
The foot inversion assessment measures the mobility of the inverter muscle group, which involves turning the foot to angle the bottom toward the midline. This motion aids in stabilizing the foot during activities like walking or running on an uneven surface.
Step-by-step explanation:
The foot inversion assessment measures mobility of the inverter muscle group. Inversion is the turning of the foot to angle the bottom of the foot toward the midline, and it involves the multiple plane joints among the tarsal bones of the posterior foot. This motion helps to stabilize the foot when walking or running on an uneven surface.