What portion of the brain controls balance and posture?
The cerebellum is the second largest portion of the brain. It is shaped somewhat like a butterfly. It is located beneath the occipital lobes of the cerebrum.
The position of cerebellum :
It consists of two partially separated hemispheres connected by a centrally constricted structure called the vermis.
The cerebellum functions as a reflex center in coordinating complex skeletal muscular movements, maintaining proper body posture , and keeping the body balanced.
The diagram shows different parts of cerebellum with their functions, see the spinocerebellum regulates the muscle tone (associated with posture) and vestibulocerebellum maintains balance :