Crossing the Midline

 by Katherine J. Collmer, M.Ed., OTR/L

Children who experience difficulty with the mastery of handwriting skills are often struggling with crossing their body midline.   During the performance of handwriting tasks, the arm, hand, and eyes travel from the writer’s left side to his right, crossing the body’s center many times.  Letter formations also rely upon the writer’s ability to cross from left to right to cross a “t” or produce an “x.”  A developmental skill need that limits the fluid movement across midline prevents a child from mastering the basic facets of handwriting mastery.

What is Crossing the Midline?

Crossing the midline is a bilateral skill demonstrated by the ability to spontaneously move one hand, foot, or eye into the space of the other hand, foot, or eye.  This happens when we sit cross-legged on the floor, scratch our elbow, read or write from left to right, draw a horizontal line from one side of the paper to the other, or connect intersecting lines to draw a cross without switching hands.  Crossing the midline is a coordinated movement that is developed as a child experiences activities that include cross-lateral motions, such as reaching across the body to retrieve a toy.  These movements help to build pathways in the brain that facilitate the development of various motor and cognitive skills involved in completing self-care tasks, participating in sports, reading, and writing.

Crossing the midline is an integral skill related to bilateral coordination.  Bilateral coordination is defined as the ability to use both sides of the body together in a coordinated, controlled, and organized manner during tasks that require the use of one hand to stabilize and the other to perform simultaneously.   These activities include crawling or climbing stairs, catching or throwing a ball, manipulating clothing fasteners, tying shoes, stringing beads, cutting, and handwriting.  In addition to the foundational skills of eye-hand coordination and muscular strength, the development of bilateral coordination is dependent upon an accurate body awareness.  This perceptual skill represents the ability to know where the body and its parts are positioned in space without using vision allowing for the spontaneous and efficient completion of tasks.  The development of bilateral coordination indicates that both sides of the brain are communicating effectively in the sharing of information.  The development of a “helper” and a “worker” hand to facilitate bilateral movements is a sign that the brain is maturating and that brain lateralization is occurring.  The lateralization process is strongly correlated with the ability to cross midline.

Brain lateralization is defined by the ongoing process that is thought to begin in the prenatal period and continue throughout early childhood. The cerebrum consists of two hemispheres (or halves) that specialize in different functions which control different areas of the body.  The left hemisphere controls the right side of the body and contains the centers for the understanding and use of language (listening, reading, speaking, and writing), memory for spoken and written language, analysis of information in detail, and motor control of the right side of the body.  The right hemisphere controls the motor movements of the left side of the body and contains the centers for processing visual-spatial information, comprehending and remembering things you see and do, and using pieces of information to form a complete picture.  The two halves are connected by a band of fibers called the corpus callosum which plays an important role in integrating their respective functions.  Lateralization becomes specialized to serve particular functions and involves a preference for using one hand or side of the body more than another.  Hand dominance is a result of brain lateralization.  (1, p. 176-7)

What are the behaviors that indicate difficulty with Bilateral Coordination and Crossing the Midline Skills?

Children who have difficulty with these skills may display decreased coordination and motor control, tend to avoid crossing their midline by using alternate hands for performing tasks on each side of their body, and have difficulty establishing hand dominance.  These children may appear to be ambidextrous because they use both hands alternately during and among tasks.  However, they may actually be doing that because they have two unskilled hands.  In addition, children who experience problems with crossing the midline can have difficulty with higher level skills such as reading and writing as they both involve left-to-right eye and hand movements.   This may be observed as stopping in the middle of the page to blink or rub their eyes, losing their place frequently during close work tasks, being unable to master letter formations that include diagonal lines, or stopping in the middle of the page to switch hands during handwriting assignments.  For children who have an inaccurate sense of body awareness, they may appear clumsy and cautious with movement especially when it involves having their feet of the ground.  They may seek or avoid deep sensory input or have difficulty coordinating both sides of their body to complete bilateral activities of daily living.  These behaviors also can result from inefficient eye-hand coordination and muscular strength.

What are some activities to promote the development of Crossing the Midline Skills?

The activities listed below are some examples of easy-to-implement tasks or games that will enhance the underlying skills that promote the development of crossing the midline skills.

For younger children:

• Obstacle course activities performed inside or outside that encourage crawling and climbing using verbal commands for directional concepts such as over and under, back and front, and up and down promote gross- and fine-motor muscle strengthening, the understanding of directional concepts, body awareness, and bilateral coordination skills.

• Floor games such as bean bag toss or ball rolling can be designed to encourage crossing the midline by having children catch or stop the bean bag or ball on the sides of their body versus the middle (e.g., using the right hand to perform the task on the left and vice versa).   Have the child call out the side of his body where he has caught or stopped the object.  These activities encourage body awareness, balance skill development, and midline crossing as the child reaches with one or both hands across the body to perform the task and identifies the sides of his body.

• Sitting or standing games such as bean bag toss can encourage the child to reach for and pick up an object on the opposite side of the body and throw it at a target on the reverse side (e.g., picking up a bean bag located on the left side with the right hand and then throwing it at a target on the right side and vice versa.)  Provide verbal directions to direct which hand the child will use or have him call out which hand he intends to use before he begins each toss.  This activity encourages balance, midline crossing, and visual attention skills.

• Push and pull toys or activities that are performed at midline such as pop beads, connecting blocks, lacing, hand exercises (pushing palms together at chest level), or rolling putty into a long snake encourage bilateral coordination, crossing the midline, and upper extremity muscle strengthening skills.

• Pretending to drive a car using a ball promotes midline crossing as the child holds the ball in both hands and turns it like a steering wheel by crossing his arms over each other as he drives. This can be adapted for children who have sufficient upper extremity strength by having them perform the activity without the ball.  This activity promotes upper extremity muscle strengthening, bilateral coordination, and crossing the midline skills.

• Clapping and popping bubbles performed in either sitting or standing can encourage engagement in the left, center, and right space in front of the child.  This activity promotes visual attention, bilateral coordination, midline crossing, and upper extremity muscle strengthening skills.

• Keeping time to music by clapping hands, alternating clapping hands and patting knees, tapping sticks together, or marching in place promote crossing the midline skills.  These activities as well as playing games that include following directions such as Simons Says or Hokey Pokey promote balance, body awareness, bilateral coordination, and visual attention skills.

• Batting a balloon back and forth in sitting or standing promotes balance, visual attention, and crossing the midline skills.

• Upper extremity exercises performed in either sitting or standing can promote midline crossing skill development.  Exercises can include touching toes with the opposite hand, performing windmills above the head or windshield washers in front of the body (crossing arms back and forth over each other), tapping opposite shoulders with the hands, hugging the body, or swinging lowered arms back and forth slowly across and behind the body.  Provide verbal directions or have the child call out the directions for each hand or side being addressed.  These activities promote balance, body awareness, bilateral coordination, crossing the midline, visual attention, and upper extremity muscle strengthening skills.

• Large arm movement activities in the air that cross from the child’s left side to his right side and reverse, such as drawing large crosses or figure 8’s (an 8 turned on its side or the infinity symbol) promote midline crossing development.   Activities that include practice for letter formation strokes (circle, up/down, or left/right strokes) can be adapted to address midline skills by first producing the letter on the left side, then in the middle, and finally on the right side using the child’s preferred hand.  Large arm movements in the air promote balance, upper extremity muscle strengthening, bilateral coordination, and midline crossing skills as well as visualization skills for automatic motor memory patterns.

• Large movement activities performed on the floor on a large piece of paper or on a sidewalk can encourage crossing the midline.  Have the child trace large crosses or figure 8’s (drawn on their side) using different colors of chalk to create rainbow tracings, drive a toy car through a figure eight driveway, or complete a large simple maze with chalk or colored pencils.  These activities promote visual attention, bilateral coordination, and crossing the midline skills as well as upper extremity muscle strengthening with crawling and movement on all four’s.  The use of chalk provides tactile input to promote handedness and writing/drawing tool control.

• Tracing activities on a vertical surface that use large arm movements that cross from the child’s left side to his right side and reverse, such as drawing large crosses or figure 8’s (drawn on their side), driving a small car through a roadway system, completing a simple maze, or drawing lines on which to practice letter strokes. These activities promote bilateral coordination and crossing the midline skills.  In addition, activities that are performed on a vertical surface promote upper extremity muscle strengthening and visual attention skills.

For older children:  While some of the activities listed below were also listed for younger children, they can be enhanced for the older ones by increasing the challenges with time or speed elements or the inclusion of academic tasks.

• Large arm movement activities in the air that cross from the child’s left side to his right side and reverse, such as drawing large crosses or figure 8’s (an 8 turned on its side or the infinity symbol) promote midline crossing skills.  This activity can include practicing letter formations or spelling words in the air using his preferred hand, first on the left side, then in the middle, and finally on the right side.  Large arm movements in the air promote upper extremity muscle strengthening, bilateral coordination, midline crossing skill as well as visualization skills for automatic motor memory patterns.

• Large movement activities that combine arm and leg movements such as drawing or writing on a large piece of paper or a sidewalk promote crossing the body midline.  Have the child trace large crosses or figure 8’s using different colors of chalk to create rainbow tracings, use a pencil to “drive” through a figure 8 pathway, copy a drawing, or complete a large maze with chalk or colored pencils.  These activities promote visual attention, bilateral coordination, and crossing the midline skills as well as upper extremity muscle strength with crawling and movement on all four’s.  The use of chalk provides tactile input to promote handedness and writing/drawing tool control.

• Tracing activities on a vertical surface that provide large arm movements that cross from the child’s left side to his right side promotes midline crossing.  These activities can include copying a drawing, completing an age-appropriate maze or word search, or drawing lines on which to practice spelling words.  These activities promote bilateral coordination as well.  In addition, activities that are performed on a vertical surface promote upper extremity muscle strengthening and visual attention skills.

• Keeping time to music by clapping hands, alternating clapping hands and patting knees, tapping sticks together, or marching in place promote balance, body awareness, bilateral coordination, and visual attention skills.

• Batting a balloon back and forth in sitting or standing promotes balance, visual attention, and crossing the midline skills.  Using a balloon instead of a ball increases the challenge and enhances the development of these skills.  Adding a verbal task such as reciting the alphabet or answering questions further increases the activity’s challenge.

• Upper extremity exercises performed in sitting or standing can include touching toes with the opposite hand, crossing the right hand to touch the raised left knee and alternating sides in a rhythmic fashion, jumping jacks, or running in place with exaggerated arm movements.   These activities promote balance, body awareness, bilateral coordination, crossing the midline, visual attention, and upper extremity muscle strengthening skills.  Adding small, light weights or a verbal task, such as reciting the directions aloud during the task will further enhance development of visual attention, crossing the midline, and bilateral coordination skills.

• Ball toss, catch, or kick games in standing or sitting promote visual attention, body awareness, balance, midline crossing, and upper extremity strengthening skills.

• Construction toys and crafts that encourage the use of two hands to construct a product promote bilateral coordination, crossing the midline, fine motor strengthening, and visual attention skills.

• Board or card games such as strategy games or solitaire can encourage visual scanning from left-to-right. These activities, as well as most board or card games, promote visual attention, bilateral coordination, and crossing the midline skills.

• Mazes, word search, hidden picture, and tangrams performed on a vertical or horizontal surface promote visual attention and crossing the midline skills.  Activities performed on a vertical surface promote upper extremity strengthening skills.

• Yoga postures. These activities promote body awareness, balance, bilateral coordination, crossing the midline, visual attention, and muscle strengthening skills.

• Playing sports or tug-of-war.  These activities promote balance, visual attention, bilateral coordination, crossing the midline, and muscle strengthening skills.

Crossing the midline skills are developmental and should appear by the age of 3-4 years.  This article is meant to provide information about its development and the symptoms that indicate a need in this area.  If you find that your child has not achieved this milestone by the age of 4, it would be wise to consult with his or her pediatrician to determine if there is an actual need that would benefit from intervention.

Katherine J. Collmer, M.Ed., OTR/L, owner, Handwriting With Katherine

Katherine J. Collmer, M.Ed., OTR/L, is a pediatric occupational therapist who specializes in the assessment and remediation of handwriting skills and understands the link between handwriting skills and writing.  She can be contacted via her website, Handwriting With Katherine.

 Disclaimer: The information shared on the Handwriting With Katherine website, blog, Facebook page, Twitter page, Pinterest page; in the Universal Publishing Handwriting Teachers’ Guides; on any guest blog posts or any other social media is for general informational purposes only and should not be relied upon as a substitute for sound professional medical advice or evaluation and care from your physician/medical team or any other qualified health care providers. Therefore, the author of these links/posts take no responsibility for any liability, loss, or risk taken by individuals as a result of applying the ideas or resources.

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References:

1. Shaffer, David R., and Katherine Kipp. Developmental Psychology: Childhood and Adolescence. 9th ed. Belmont, CA: Wadsworth, 2013. Print.

2. Edwards, Marissa, M.S., OTR/L. “Help Your Child Develop the “Crossing the Midline” Skill.” Nspt4kids.com. North Shore Pediatric Therapy, 18 Apr. 2011. Web. 28 Oct. 2015. <http://nspt4kids.com/parenting/help-your-child-develop-the-crossing-the-midline-skill/>.

3. “What Is Brain Lateralization?” Nspt4kids.com. North Shore Pediatric Therapy, n.d. Web. 28 Oct. 2015. <http://nspt4kids.com/healthtopics-and-conditions-database/brain-lateralization/>.