Muscle knots in the Flexor Hallucis Brevis are located on the bottom of the foot, just beneath the big toe and the ball of the foot. Muscle knots refer pain to the ball of the foot and the base of the big toe, and sometimes the inner arch of the foot. This can mimic symptoms of gout or a bunion, characterized by a sharp, localized pain that is felt during weight-bearing activities. The pain is often described as a deep ache and can be intensified by pushing off with the big toe.