This is a fancy way of saying coordination between the
right and left sides of the body. In the grand sense of the term, it
means everything that our body does across its midline. This means any
signals sent from one side of the brain to the other. It means the two
eyes tracking a flying ball together. It means coordinating the muscles
on both side of your trunk and neck to twist around and look at
something behind you while seated. Likewise, it means using those same
muscles in more subtle contractions to keep your balance while you
walk and run. It means being able to move your tongue side-to-side in
mouth because the lateral muscles on either side of your tongue work
together. In the area of fine motor, people are usually talking
about using the two hands together or else about hand dominance when
they talk about bilateral integration. However, all of these areas are
interrelated, and someone who has significant bilateral integration
dysfunction will probably have a cluster of difficult areas such as
balance, smooth eye tracking, and coordinated use of both hands
together, and possibly language processing delays as well. I have
heard that frequent ear infections can be related to bilateral
integration problems, and tracheostomies have been linked to
poor bilateral integration.
For working on hand use, we need to look at hand dominance and whether
it has been established pretty firmly. This should happen for tool use
by about five and one-half years of age. Indications of developing
dominance should be present by three years (reaching and holding
more with one than other hand). True ambidexterity is different from
difficulties with bilateral integration which have stalled the
development of laterality. As an adult, being ambidextrous
interesting and not usually a problem, and about 12% of people are
ambidextrous (some say that Einstein was). But when you are first
to master motor coordination in many different and new tasks, the
process is often made more difficult when your brain has to decide each
to send the commands!
Many parents report that their children
will do everything with one hand but then write and maybe eat with the
other hand. Or they will switch around. If the child's central
system hasn't established which hand is the "default" side to send the
most-active motor commands to, other factors will help it make that
decision for each task. For example, kids who switch back and forth may
be reaching with whichever hand is on the side of the target, and will
just use that hand to manipulate the object rather than shift it to the
other hand. Or they may be using the side that has the stronger eye if
their two eyes aren't working together well. So they will do
large movements (throw, reach, touch) with one side (the slightly more
dominant hand) but then write and do tasks that require careful close
looking with the other hand (if the opposite eye is working better
Then we need to look at using two hands together smoothly. First,
children learn to use two hands together for a symmetrical activity.
Think of a toddler banging pot lids together. Then they learn to hold
one hand still while the other works, and finally to use both hands
simultaneously for different movements. This is what is necessary to
turn a paper with one hand while cutting out a circle with the
other. Add in all kinds of fancy motor planning and you have
playing a musical instrument.
For activities to work on bilateral integration, click here.
Believe it or not, problems with handwriting can stem
from problems with seated posture and shoulder positioning. Think of
your body for a moment as a robot whose job is to
etch small marks into a specific area. If your robot arm is attached
to a wobbly, unbalanced, or weak base, how can it be in just the right
place and use just the right small movements to do its job?
The same is true of a student sitting and writing. If he lacks the
muscle strength to hold himself upright in a chair (or has sensory processing or attentional issues
that prevent him from sitting for more than a few moments at a time),
ability to place and control his hand and fingers will be compromised.
Usually muscle tone
and/or strength issues are seen in conjunction with poor postural
stability, and these are usually seen throughout the body, so that
poor posture is rarely an isolated cause of handwriting problems.
However, even with strengthening and skill building within the hand,
if postural and shoulder stability deficits are not addressed,
functional fine motor skills will be difficult.
For exercises to work on postural and shoulder stability, click here.
No other upper extremity (i.e. arm) joint can
for wrist limitations. Children with fine motor delays often compensate
for inadequate stabilization of the wrist by flexing the wrist (bending
it forward so palm gets closer to forearm) to "lock" it into a stable
position. This is a poor position for dexterity and range of motion
with fingers and thumb. By contrast, a slightly extended wrist position
(wrist bent back so that palm is farther from forearm) allows for
better thumb positioning, arching of the hands, and isolation of finger
movements. Try it now: pretend you are about to thread a needle. Now
look at your wrist position. It is most likely bent back
slightly into extension. Now try flexing your wrist forward as far as
you can and try to thread your imaginary needle. It is harder to move
the fingers and thumb together as the tendons are in a shortened
position. (That's why it's so hard to fasten a bracelet using the hand
The same applies to holding and using a pencil or any other fine motor
tool. Strengthening the wrist extensor muscles, which run all the way
across the wrist from the back of the hand and the wrist bones
themselves to the elbow, can be an important step for working on fine
For exercises to work on wrist stability, click here
There are two transverse arches, four longitudinal
arches, and four diagonal or oblique arches of opposition in your
hands. These arches shape the hand to grasp differently-shaped objects,
direct the skilled movements of the fingers, and grade the power of
grasps. All skilled movements within the hands work off of these
arches. For a tour, cup your hands as if you are going to scoop up
water. Now pinch your thumb and pinky together. Take a moment to marvel
at all the positions your thumb can reach across your palm and fingers.
Some small amount of palmar arch development is present at birth, but
it takes place as we develop in our first few years. When we
weight-bear on our palms (crawling and scooting), we strengthen the
muscles that pull the pinky side of our hand up into an arch.
Children who didn't spend much time crawling often need some extra
work on their hand arches. Those pinky-side muscles, the muscles
running from the base of our thumbs, from bone to bone in the hand, and
at the base of each finger continue to strengthen as we begin to grasp
onto large (stuffed animal) and then later small (cheerios) objects. By
Kindergarten, these arches should be pretty well-developed and ready to
with large-diameter writing tools.
I test these arches by asking children to cup their hands and shake
dice, to "make spiders" on a table with their fingers, and to move
their pinky and thumb together and apart several times. I look for the
depth of the "bowl" in the palm and for movement at the base of the
pinky to pull it up into opposition to thumb. There should also be
wrinkling of the muscles along the pinky-side of the palm as the
muscles there contract.
For exercises to work on developing the arches of the hands, click here
Opposition and Opening Webspace:
For effective manipulation within the hand, the thumb must move into
full abduction with rotation inward so that thumbtip can touch any
fingertip. From this position, a triad of thumb muscles, those most
densely supplied with sensory receptors to provide feedback to our
brains, will guide movements and regulate pressure for speed and
dexterity. This is the position that is facilitated by wrist extension
Many children (it seems like about 25-50% to me when I walk into any
first grade classroom) don't have good stability and strength
through these three muscles and the base of the thumb. They often
substitute one larger muscle that pulls the thumb in against the side
of the index finger, closing the thumb-index
webspace. When holding a pencil, this substitution means a pinched-in
thumb position rather one with a round webspace and the thumbtip on the
pencil. It could be a thumbwrap, a thumbtuck, or another ineffective
. Often, these pinched-in grasps will mean heavy pressure of
pencil against paper, quickly fatiguing hands, and difficulty keeping
their pencils or coloring tools where they want the marks on the paper.
I measure stability of thumb webspace by having children do a few
pinching-type tasks (close a Ziploc bag, squish a ball of putty into a
pancake) and by having them form the "OK" sign with thumb and index
while I try to pull it apart with my two hooked pinkies. I also watch
how they hold a pencil with and without pencil grippers while writing.
For exercises to work on improving thumb opposition and webspace, click
of Function of the Two Sides of the Hand:
Refinement of skill with the radial (thumb-index) side of the hand is
achieved when the ulnar (pinky) side of the hand is stabilized. When
ring finger are still -- either curled into the palm or are stretched
extension away from the other fingers -- we are best able to control
middle and index fingers and thumb for precise motions. Try it now:
pretend to thread a needle and look at your pinky and ring finger on
your active hand. Pretend to wind a small knob, such as on a
watch, and check again. They should not be moving along with your index
offers the most stability through the hand while allowing free movement
of the digits which are working on the fine motor task.
Early separation of the two sides of the hand is sometimes present at
birth. It develops when an infant crawls and bears weight on the
pinky side of the hand while carrying toys with the thumb and index
side. A different nerve controls some of the muscles of the pinky and
ring fingers from the index, middle, and thumb digits, and with
we learn to inhibit movements of ring and pinky while the other digits
are working. There is a little ligamentous link between the tendon of
the middle and ring fingers which make it more challenging to
extend our ring finger without moving the middle finger. Therefore,
some slight connected movements are often seen between these two
fingers, but effective separation can occur even so.
When writing, this separation is important because it allows us to
stabilize the side of our hand and pinky against the page so that we
can slide along and keep our writing on the line without much effort.
Try writing on a line while not allowing your hand to touch the paper.
Cutting with scissors requires separation of the two sides of the
cutting hand for precision in steering while opening and closing the
To assess this in a child, I watch for automatic separation of function
(curling in or stretching out pinky and ring fingers) while cutting,
snapping, threading a large needle, moving pegs, and flipping pennies
over. Spinning a top and winding a toy are amongst the other activities
where this separation should be observed.
For exercises to work on separating function of the two sides of the
hand, click here.
This refers to the ability to shift objects about with the fingers of
one or both hands, such as to examine an object by touch or vision, or
to get something oriented just so, or to position something for the
best grasp. This depends on mobility and coordinated control at the
base joints of your fingers (called metacarpal or MP joints), which
allow for thumb-finger oppositions
different positions. Children who are lacking these higher-level
fine motor skills often appear "fumbly" when trying to use their
fingers to maneuver small objects. They may use two hands for a task
that we would consider a one-handed task, or they may set down an
object to pick it up a different way rather than shifting it within the
There are many different such movements possible, and they have been
termed differently by different people. The terminology that I use is
based on a combination of that used by two well-known occupational
therapists who have each written extensively on developmental fine
motor skills, Mary Benbow and Charlotte Exner. Here is a breakdown.
is the act of turning something (of course), but
there several types. Simple rotation can be seen when you pick up a
pencil that is oriented across your body and then flip it
about in your hand so that it is in the writing position. If you try
this, you'll see that one way is simpler than the other, depending on
whether the point of the pencil is facing to the right or to the
left. Precision rotation involves turning something in the
fingertips, such as rotating a coin to read the words around the edge
or to flip a coin over and over in the fingertips. Finally, there is a
lateral shift movement of the thumb against fingers such as to wind up
a small toy,
that some people call rotation.
is the movement of
objects between palm and fingertips, such as selecting one coin from
several in your palm and moving it to the fingertips with only one hand
active. Also referred to as squirreling (to palm) and de-squirreling
(to fingertips) small items.
is the balanced movement
with opposed thumb and finger such as to thread a needle, push a button
through a hole, pick a small bit of lint off of fabric, or poke a pin
into a pincushion.
For exercises to work on in-hand manipulation skills, click here.
There are over 25 muscles of each hand. Overall weakness
of these muscles can be an issue in fine motor skill development. Often
some muscles are notably weaker than is typical and this makes certain
types of grips or movements more difficult than others. Keep in mind,
that the higher-level manipulation skills require a good balance of
strength and stability throughout the hand so that any area of weakness
will impact them.
Often, children have over-strengthened some muscles because of
substituting those muscles for less-developed muscles. This is seen
frequently in the muscles that attach at the base of the thumb that allow for positioning in
opposition and skilled movement there. Rather than using the more
skilled triad of thumb opposition muscles, children will substitute one
larger but less skilled adduction/flexion muscle.
Also, the extensor muscles of the hand develop later than the flexor
muscles, and often strength issues are more notable in extension. For
example, lifting each finger up from a "spider" position on a table is
often more difficult than curling each finger up from a palm-up
For exercises to work on overall hand and finger strength, click here
a link to an exerpt from a book chapter that discusses the development
of various grasp patterns, definitions of different grasps, and at what
ages different authors found that these grasps develop. It is really
designed for OTs and others who would be studying child fine motor
development. But if you scroll down there are some really nice pictures
of different grasp patters and these help to illustrate some of the
aspects of fine motor discussed above.