The midline of the body is an imaginary, vertical line dividing the right and left halves of the body equally.

Crossing the midline is the ability to use one side or part of the body (hand, foot, or eye) in the space of the other side. Infants have to learn how to do this; they start by reaching their hands together at midline.

A child who is unable to cross midline might switch hands during scissor or writing activities. This skill is used in everyday activities, such as reading and writing. Consider reaching out to our occupational therapists if you notice your child having difficulties with this skill.

A baby in a white/grey striped onesie is lying on their back reaching for their feet at midline with both hands. Midline is represented by a blue dotted line reaching from head to bottom in the middle of the eyes, nose, chin, and body.
Midline shown here as a blue, dotted line.