If you imagine the ‘midline’ as a straight line down the center of the body from head to toe dividing the right side from the left, then “crossing the midline” means extending reach or vision from one side of the body into the space of the other side. Crossing the midline involves effective Bilateral Coordination skills (the ability to use both sides of the body at the same time) and Cross-Lateral Motion skills (movement involving the left arm and right leg or the right arm and left leg at the same time). Bilateral Coordination can involve using the two sides for the same action (washing your hands), alternating actions (climbing stairs), or separate actions to achieve the same goal (stabilizing a paper with one hand to write with the other). Typical neurological development for bilateral coordination occurs between the ages of 3 and 10. Effective bilateral coordination and crossing the body’s midline are essential for fluid body movements, the development of fine and gross motor skills, and visual tracking skills. Children unable to cross their body’s midline often have trouble reading and writing. The “Brain Gym” program offers exercises that involve midline crossing and cross-lateral motion that can help to jump start the brain’s development for bilateral coordination (braingym.org).