Final answer:
If tibialis posterior is overactive, the most likely outcome is increased plantarflexion of the foot. This can lead to issues such as foot pain, decreased flexibility, and changes in gait.
Step-by-step explanation:
If tibialis posterior is overactive, the most likely outcome is increased plantarflexion of the foot. Tibialis posterior is a muscle located in the posterior compartment of the leg that functions to lower the sole of the foot to the ground.
When it is overactive, it causes excessive plantarflexion, which means the heel is lifted off the ground and the toes are pointed downward, resulting in a contracted position of the foot. This can lead to issues such as foot pain, decreased flexibility, and changes in gait.