Developmental Coordination Disorder Clinical Presentation

The diagnosis of problems in motor skills and coordination relies on a careful history of functioning while the child is performing motor tasks, a history of development in the motor and sensory integration areas, and physical findings.

In May 2013, the Council on Children with Disabilities published guidance on the early identification and evaluation of motor delays in children, which include formal developmental screening of children for possible motor delays and variations in muscle tone at their 9-, 18-, 30-, and 48-month well-child visits. ^{[1, 2]}

The Council advises that pediatricians not only should watch how children perform requested tasks but also should pay close attention to general posture, play, and spontaneous motor functions.Muscle tone deficiencies may also indicate neuromotor delays from disorders such as cerebral palsy.

Children who find performing certain motor tasks difficult, frustrating, or even impossible often become discouraged and subsequently avoid these tasks altogether. Statements such as “I hate to draw,” “I hate writing,” or “I hate sports” may be their way of disclosing their feeling of incompetence while attempting to save face. Eventual avoidance of challenging physical tasks in a child who works hard on drawing or writing with poor results is understandable. Children with developmental coordination disorder (DCD) often end up feeling angry, frustrated, or sad.

Because children may not volunteer that in addition to not liking specific activities or tasks, they feel inadequate in performing them, the true problem is often difficult for parents and clinicians to identify. When a child reports not enjoying most physical activities, careful observation may be required after the child is asked to perform a few motor tasks to demonstrate the degree of challenge these activities pose to the child.

When the condition is serious and noticeable to everyone, the child is most likely to be stigmatized at school and often at home. Children with motor coordination difficulties often feel ashamed of their poor ability to perform many motor tasks, especially those required to participate in sports and to achieve skills in school (eg, cutting with scissors, coloring, drawing, and writing).

The manifestations described above are based on the assumption that children have the opportunity to practice motor activities and are taught them. Children require a minimum of exposure and practice to develop dexterity with scissors and drawing. A child who is notably neglected or not exposed to usual physical tasks may have physical deficits for these reasons.

Crucial aspects of motor development include the following:

• Exposure to tasks

• Caretakers who recognize the child’s developmental needs

• Opportunities for the child to be taught skills

• Appropriate stimulation of the child

• Opportunities for the child to develop and practice new movements

These aspects are part of the dynamic theory of motor development, which postulates that children develop new motor skills as they are needed, depending on the interactions with the environment and on the challenges presented. Practice, experience, and environment are important determinants of development, in addition to the child’s intrinsic genetic capacities. Development is shaped by a process of selection in which children develop movement repertoires that are optimal for functioning in their specific environmental conditions.

The clinical picture of motor coordination problems is assessed from a developmental point of view—that is, by considering normal physical capacities at different ages. Evaluation of a child’s development includes a consideration of individual variation (eg, by factoring in the range of time at which motor skills are normally acquired). Evaluating the overall development of a child is preferable; the characteristic style, strengths, and weaknesses of each child must be taken into account.

Manifestations in infancy

Infants with difficulties in motor functioning may appear either hypertonic or hypotonic. If infants react strongly to any slight auditory or visual stimulation by becoming stiff or by arching the back, this is a sign of hypertonicity and hyperreactivity. Young infants maintain flexor tone in the first few months of life and only gradually develop extension patterns. Newborns that lay in a frog-leg posture suggest hypotonicity.

When parents report that their baby is strong (ie, that the muscles appear hard and tense), this merits careful examination of motor patterns. Clinicians should allow for individual variations; however, if primitive reflexes (eg, Moro, plantar, or rooting reflex) persist after 6 or 7 months, concern regarding motor development is warranted. A single sign may be insignificant, but persistence of several primitive reflexes should elicit full examination of motor functioning and overall development.

Anecdotal data suggest that infants in some racial groups (eg, African Americans) generally achieve gross motor skills more quickly than children of other racial groups. When small infants appear almost ready to walk at a few months of life, this is a sign for concern. Infants who move as an entire unit without correcting the angle of the head toward the vertical line when held sideways may have a motor developmental problem.

Infants with motor challenges are often delayed in achieving milestones such as the ability to roll over, to sit with help, and to sit without help. Infants with motor problems may not be able to sustain their weight after 6 months when supported under their arms. They have a tendency to slip through the supporter’s grasp. This signals muscular hypotonicity.

At about age 4 months, infants can start anticipating the movement of objects, showing early visuomotor development. They should also be able to pull to a sitting position without head-lag and be able to maintain their body in extension when suspended in horizontal posture; persisting head-lag or floppiness during suspension are indicative of hypotonicity.

At about age 6 months, infants can usually oppose the thumb in the grasping motion. Most infants can sit without support also around this age.

By age 9 months, while sitting by themselves, infants should be able to self-correct posture when tilted to one side or the other, rather than just being tipped over. In some infants, these self-correcting (postural) reflexes are absent. Infants also develop a refined pincer grasp around this age. If the infant is not able to sit unassisted by age 9 months, this deficit should concern the clinician and prompt detailed examination.

Infants who stand and who always point down with their toes may also be signaling hypertonicity of the lower limbs (or generalized hypertonicity) and high sensitivity to touch in the plantar surface of the feet. These infants may later walk on their tiptoes.

Scratching the bottom of the foot may elicit an upgoing big toe (positive Babinski sign) in the first year of life, but this should revert to a downgoing toe by age 10-12 months. Persistence of the Babinski reflex is a sign of hypertonicity.

Crossed-adductor reflexes and clonus at the ankles may be seen during the neonatal period, but persistence of these is evidence of hypotonicity.

Manifestations in the second and third years of life

Subtle difficulties in motor functioning may be difficult to identify in the early years of life. For instance, toddlers who have subtle motor skills deficits in chewing may not accept foods that require greater chewing ability. Eating solid food requires the coordinated functioning of approximately 31 pairs of muscles and the coordination of breathing with the swallowing of the bolus. Toddlers who do not eat solids may be displaying a marker of motor challenge that extends beyond chewing. This also applies to toddlers who repeatedly choke on chewed food.

Children may have difficulty in making a pincer grasp (ie, picking up small objects with the index finger and the thumb). A pincer grasp normally appears around month 8 or 9 but may appear later. It can be tested by allowing children to pick up a small object (eg, a piece of breakfast cereal) from a flat surface. Infants may continue trying to pick up these objects with a palmar grasp (ie, with the whole anterior surface of the hand). If so, they should be observed for fine motor delay.

At the end of the first year of life, most infants start making efforts to walk while holding onto furniture and take their first steps shortly afterward. Infants who are unable to walk by age 18 months may have hypotonicity or hypertonicity, poor muscular strength or coordination, or difficulty with managing equilibrium, balance, and posture. In a 1990 study by Bax et al, most children who did not walk at age 18 months turned out to be healthy, but a small percentage had motor difficulties, including cerebral palsy and other developmental delays. ^[21]

The ability to walk depends largely on the capacity to maintain balance and not fall over. Walking takes more than the sheer muscular strength required to support the weight; the challenge is to displace the weight in a controlled fashion without falling. Both abilities are necessary, however. Other factors involved in walking onset include temperament style, opportunity, and motivational factors.

Manifestations in preschool- and school-aged children

At age 3-5 years, many skills are acquired and refined with exposure to activities and games that require motor practicing. Obviously, children differ from one another in the speed of their development; accordingly, strict dates or milestones of age that are totally accurate cannot be established.

By age 2 years, many children can make a brief 2-foot takeoff jump if someone holds their hands. At age 3-4 years, most children can hop on 1 foot; with the dominant leg, they can hop about 3 times. At age 5-6 years, children can typically perform this hopping about 10 times. By age 5 years, most children can jump about 3 feet in distance and about 1 foot in height.

By age 4-5 years, most children have developed a clear hand preference or dominance. Lack of a hand preference may signal that the normal dominance and specialization of the brain hemispheres is not occurring. Such children do many things with either hand or with 1 hand at some times and the other hand at different times.

In some cases, true ambidexterity is present (the ability to actually perform tasks well with either hand). However, in many cases, the brain is not developing adequate specialization of neuronal pathways to permit control of motor function with one hemisphere. In those cases, the clinician can observe hesitations and the inability to select one side or the other, resulting in relative clumsiness in both limbs.

Alternatively, children may demonstrate early hand preference. This indicates that the nondominant side may be weak or poorly coordinated, and investigations are warranted to determine whether a structural cause is present.

Another sign that is cause for concern is difficulty with maturation of pencil grasp. Concern arises in children who have sufficient practice opportunities but still cannot hold a pencil with a mature pattern. Occupational therapy is essential for these children; poor quality or difficulty with handwriting can lead to later academic difficulties.

Many experts think that difficulties in fine motor skills (eg, managing the fingers and wrist) are a reflection more of malfunctioning in the proximal areas of the upper limbs than of malfunctioning in other areas.

Children may be unable to handle the pen, crayon, or pencil in the dynamic tripod pattern that is considered the mature and efficient way to tackle writing tasks. During that activity, only the wrist joint moves, while the other joints in the upper limb remain fixed. When the shoulder girdle is weak, however, children must compensate when they have to use the distal part of the upper extremity (fingers and hand). Instead of using the wrist to write, children have to move the entire upper limb to write.

Inability to hold and use a pencil in a typical fashion may indicate a problem in differentiating various muscle areas and activating them at will. Thus, tasks such as writing and painting become less efficient, because children must use extra energy to perform them; controlling the whole limb requires more energy than just controlling the wrist. As a result, children who cannot use the proper grasp tire quickly and report that their hand hurts when writing. After a few minutes of drawing or writing, they may give up entirely because it hurts them to continue.

These problems may be additive because teachers who are unaware of these difficulties may believe that the students are lazy or defiant. In objective terms, affected children are incapable of performing these delicate and fine movements until they maturationally achieve good differentiation of motion between the shoulder joint and the rest of the limb. The condition is treated with programmed exercise to strengthen the shoulder belt, causing weight bearing on the area, and with planned work on the hands to strengthen the shoulder, arm, and forearm.

Physical examination can be carried out almost in its entirety in the context of everyday activities or play. The examination should include an assessment of dysmorphic features and abnormal neurologic signs. Activities or tests that evaluate children’s strength, speed of movement, sequence of movement, coordination, tone, right and left sides, and ability to perform everyday tasks in a smooth and controlled way are all important. Elements of the neurologic examination can be carried out in the context of play include the following:

• Handshaking or squeezing the examiner’s fingers to assess strength

• Throwing and kicking a ball

• Cutting something with a pair of scissors

• Drawing or coloring

• Tying shoes

• Reaching for objects with each hand

• Pointing as objects with a finger outstretched

• Taking off or putting on a coat

For the diagnosis of DCD, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), emphasizes a marked impairment in the development of motor coordination, which must interfere with academic achievement or with activities of daily living (ADLs). ^[2] A general medical condition that might explain the trouble with movement control (eg, muscular dystrophy or cerebral palsy) must be excluded, as must intellectual disability and visual impairment. Symptom onset must have been in the early developmental period.

The International Classification of Diseases, Tenth Edition (ICD 10), describes motor skills disorder as a “specific developmental disorder of motor functioning.” It emphasizes that even when no formal neurologic condition is present, careful clinical examination shows marked neurodevelopmental immaturities, perhaps choreiform movements of unsupported limbs or overflow movements (ie, mirror movements).

Other extraneous motor actions often occur when children are attempting a specific complex movement, as well as impaired fine and gross motor coordination. In addition, as in the DSM-5 description, the condition must have existed since early in the child’s life (ie, it is developmental rather than acquired). No marked difficulties in perceptual systems, such as vision or hearing, and no specific neurologic disorder should be present.

There is no universally accepted standard for testing children for motor clumsiness. The main role of the pediatrician is to detect difficulties in motor coordination and development, rather than to engage in systematic or standardized testing or therapy. There are, however, a number of tests and examination techniques that may help identify the problem, with generally comparable results.

Tests to observe tasks and abilities

Tests for observing tasks and abilities include the following:

• Test for sustaining a position against gravity

• Test for motor sequencing

• Nose-finger test

• Moving a limb (feet, legs, thighs, arms, forearms, or hands) against resistance

• Test of energy investment in a movement

• Test of the ability to perceive spatial relations

• Test of fine motor tasks

• Test for gross motor difficulties

Observation of muscular tone in sitting and standing positions gives an impression of the child’s ability to sustain a position against gravity.

Touching the thumb against the other fingers of that hand in sequence, one after the other, is a way of assessing whether the child can sequence movements at a certain speed. The clinician observes for errors in the sequence. Observing each hand and noting the effect of muscles getting tired quickly, which leads to additional errors, is important. In this activity, as in others, fine tremors of the fingers can be observed.

Also observed in testing for motor sequencing is an effect of overflow (performing a similar movement with the opposite side of the body, referred to as mirror movements), which should disappear around age 7-8 years. When children who are affected attempt a fine or difficult motion, one can observe adventitious movements, such as grimacing, sticking the tongue out, or tics (stereotypic vocal or motor manifestations related to stress, boredom, or anxiety).

The nose-finger test is performed to measure fine motor coordination, proprioception, and perception of movements in space.

Moving a limb against resistance allows the examiner to assess the child’s strength in different areas. Some youngsters have normal strength in the lower limbs but not in the upper body, or vice versa.

Testing of energy investment in a movement is done to determine whether a child can perform a movement or sequence and how difficult performance of the movement is. This issue is not often considered in the assessment of writing ability or other fine movements. A child may be able to carry out this task, but only by applying great focus and concentration, and writing a few words may take practically all of his or her energy.

Obviously, the child is soon fatigued and unable to maintain this energy-wasting activity for a long time. As a consequence, testing for only a brief period may be misleading, because it may not elicit the sustained effort and tiredness that lead to errors in performance and coordination. Sustained testing better simulates real life, where the child often must sustain an activity (eg, doing homework) for more than 2-3 minutes.

The ability to perceive spatial relations is not, strictly speaking, a motor task; it depends on proprioception and the realization of where one’s body is in space. Children with difficulties in these functions may bump into things, crash into people, miscalculate the strength of their movements, or knock down a glass that they are attempting to take from a table.

Tests of fine motor tasks can make use of activities such as coloring, drawing, or building with blocks, which directly reflect the child’s fine motor coordination. Engaging children in play with miniature toys (eg, small cups, saucers, silverware in a pretend tea party) helps in assessing their coordination of small movements.

Clinicians rarely examine motor abilities in isolation. After motor difficulties are detected, it may be necessary to investigate other areas (eg, visuomotor coordination); to test for other soft neurologic signs; or to assess attention span, writing, and reading. Deficits in these other areas are frequent comorbidities. Observations by school staff may be valuable because these individuals have daily contact with the children at times when the children are attempting to perform these tasks.

With respect to testing for gross motor difficulties, a physical education teacher or a physical therapist may be a better resource for information about physical ability in children than a classroom teacher would be, as shown in a 1997 study by Piek and Edwards. ^[6]

Many children with clumsiness or motor coordination difficulties also have other difficulties. Common problems that aggravate motor coordination difficulties in children include problems in attention and concentration, as well as attention deficit hyperactivity disorder (ADHD). The condition that Gillberg and Kadesjo described as DAMP (d eficits in a ttention, m otor control, and p erception) syndrome indicates the same connection. ^[22]

Children with autism spectrum disorders, notably those with Asperger syndrome, have long been reported to have motor clumsiness. The type of motor dysfunction observed in autism has not been properly delineated in an empiric study. A study from Sweden reported that 25% of girls with autism and 32% of those with ADHD met criteria for DCD. ^[23]

Many children with motor difficulties have speech difficulties (eg, stuttering, problems with phonology, receptive language disorders, or mixed language disorders) and may have problems in written expression and other learning disabilities as well.

These perceptual-learning problems (see Mathematics Learning Disorder and Reading Learning Disorder) may be predominant in visuomotor coordination, perceptual skills, and perception of spatial relations. The problem must be addressed from several points of view and take into account all of the child’s challenges.

Children with DCD consistently perform below their peers in ADLs. A study by Wang et al reported that in 8-year-old children who had DCD but were not identified by parents or professionals as exhibiting functional limitations, pervasive difficulties with functional performance of ADLs were evident at home and at school. ^[24]

Impairment of the ability to perform ADLs also highlights the impact on the activity and fitness levels of children affected with DCD. These children are more likely to be obese or to have poor fitness levels, and studies suggest that they are higher risk for cardiovascular disease as adults. ^{[25, 26, 27, 28, 29]} One report suggested that increased physical activity reduced body mass index (BMI) in female children with DCD but increased it in their male counterparts. ^[30]

A report demonstrated that children with probable DCD had an increased prevalence of self-reported depression and parent-reported mental health difficulties, which were, in part, mediated through associated developmental difficulties, low verbal intelligence quotient (IQ), poor self-esteem, and bullying. ^[31] Children with DCD can also have higher rates of comorbid learning disabilities, attention deficits, and other impairments in learning. ^{[26, 32]}