Motor Development in Cerebral Palsy and its Relationship to Intellectual Development: A Review Article

This review article sought to ascertain how cerebral palsy affects the development and presentation of motor skills across the lifespan, as well as examine the relationship between motor skills and intellectual ability in individuals with cerebral palsy. Motor skills development in persons with cerebral palsy was discovered to be heterogeneous, with some individuals experiencing significant motor skills development while others encountered persistent challenges. The review further established that motor skill development may differ significantly across the different subtypes of cerebral palsy. Relative to the relationship between motor skills and intellectual ability, the review established both gross and fine motor skills may be predictive of intellectual ability in persons with cerebral palsy. In light of these findings, the review highlights the implications for educators and clinicians as well as the direction for future research.

Introduction

Cerebral palsy is most characterized by motor disabilities and is defined as “a group of disorders of the development of movement and posture, causing activity limitations that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain” [1, p. 851]. These disturbances can occur prenatally, perinatally, or postnatally during the early ages of life [2]. Although described as a non-progressive condition, the motor disabilities associated with cerebral palsy tend to be more obvious as the infant/child grows [3]. Cerebral palsy is the most frequent cause of physical disability in childhood [1]. Despite motor disabilities being the predominant disorder in cerebral palsy, other co-morbidities, including disturbances in cognition, sensation, perception, vision, communication, behavior, and epilepsy, are not uncommon [4]. The specific constellation of motor and non-motor impairments varies greatly among individuals with CP, making it a heterogeneous condition [2].

Gross motor skills refer to the use of relatively larger muscles in changing positions and maintaining balance [5], while fine motor skills, otherwise known as dexterity, pertain to movements that require the manipulation of the fingers, hand and wrist and include activities such as picking up objects, holding and using writing materials and dressing [6]. These two sets of motor skills are collectively referred to as basic motor skills [7]. In typically developing children, motor skills tend to improve with age, and by 5 years of age, the bulk of basic motor skills are developed [8]. However, for most children with cerebral palsy, the development of basic motor skills is delayed and may continue to develop beyond the aforementioned age [6]. More specifically, children with cerebral palsy consistently demonstrate lower performance in various aspects of motor skill development, such as strength, balance, agility, flexibility, coordination [including hand-eye coordination], proprioception, and reaction time, when compared to typically developing children [9]–[11].

Method

The three steps utilized in this review article are outlined as follows.

Identification of the Research Question

This review article was underpinned by two research questions. The first research question focused on the trajectory of motor skills development and its presentation in persons with cerebral palsy, while the second research question examined the relationship between motor skills and intellectual ability in the same population. The specific research questions of this current review are as follows:

1. How does cerebral palsy affect the development and presentation of motor skills across the lifespan?
2. What is the relationship between motor skills and intellectual ability in persons with cerebral palsy?

Identification of the Relevant Studies

The research questions were broken down into key terms and related synonyms. With respect to the key term cerebral palsy, the following search terms were applied: cerebral palsy OR CP OR spastic cerebral palsy OR Dyskinetic cerebral palsy OR Ataxic cerebral palsy. Motor skill development OR motor function OR gross motor skills OR fine motor skills were the search terms used relative to motor skills. On the relationship between motor skills and intellectual ability, the following search terms were applied: Cerebral palsy OR cognition OR intellectual ability. Next, the search terms Motor skills OR intellectual disability OR cerebral palsy were applied. Studies ought to involve participants diagnosed with cerebral palsy [spastic cerebral palsy, dyskinetic cerebral palsy, ataxic cerebral palsy, mixed cerebral palsy]. Both cross-sectional and longitudinal studies were included in this scoping review, and only studies written in English were considered.

Four databases were utilized in this review article: MEDLINE (OvidSP), CINAHL (EBSCO), PsycINFO (EBSCO), and PEDro (PEDro Database). The authors believed these databases were the most relevant to the research questions underpinning the review. Overall, 435 studies were identified using the aforementioned terms and databases.

Study Selection

Firstly, the authors removed duplicated studies between the four databases (n = 38). The first author then read the titles of the remaining 397 studies. The second author read the titles of all 397 studies and removed those that were obviously irrelevant (some of these studies were carried out in animals). After the aforementioned exercise, 205 articles were deemed relevant to the review. The two authors then read the abstracts of all 205 articles, after which they determined that 98 of them were suitable for the full-text review. The next step involved the two authors reading the 98 studies separately, with particular attention to the methodology section of every study. With an agreement level of 100%, the two authors settled on 65 articles to be included in the review. The reference lists of these 65 articles were then scrutinized to ensure all relevant studies were included in this review. Three additional articles were deemed relevant to the review after the two authors engaged the titles, abstracts, and full texts. Thus, 68 primary articles were utilized in this review article.

Results

Gross and Fine Motor Skills Development in Cerebral Palsy

Though the exact scope, timing and extent of gross motor skills development in cerebral palsy remains unclear, a number of studies have attempted to document these changes. The earliest longitudinal study was the Ontario Motor Growth (OMG) that utilized GMFCS for children with cerebral palsy aged 1–13 years. The OMG, otherwise known as the “stable limit” model of gross motor development, predicts a rapid increase in the gross motor skills of children with cerebral palsy up to the age of 5 years, beyond which gross motor skills development is anticipated to reach a stable limit, also known as a “plateau phase” [12]. A second and more expansive study that built on the OMG study included children and young adults aged 1–21 years. The aforementioned study produced the “peak and decline” model of gross motor development in children with cerebral palsy. In this model, the development of gross motor skills is prolific in the early years of children with cerebral palsy, similar to the “stable limit” model, and peaked around the age of 7 years, followed by a period of decline [13]. Damiano et al. [14] posited that the decline in gross motor skills became more prominent as children with cerebral palsy approached adolescence or young adulthood. Day et al. [15], as well as Jahnsen et al. [16], specifically established that walking ability tends to deteriorate in children with cerebral palsy. Day et al. [15] analyzed the gross motor skills of 5721 children with cerebral palsy. The analysis revealed the children who lost their ability to walk (34%) were mostly those with unsteady gait and those who occasionally utilized wheelchairs. Consequently, Smits et al. [26] asserted gross motor development in cerebral palsy may be highly dependent on the severity of cerebral palsy; the more severer the cerebral palsy, the lower the prospect for gross motor skills development and the higher the chance for gross motor skills to decline over time. Smits et al. [26] further posited that children with less severe cerebral palsy tend to reach the limit of their gross motor development at a later age compared to those with more severe forms. However, Hanna et al. [13] averred there was no significant decline in gross motor skills for children with cerebral palsy who were capable of walking without assistive devices as they aged.

Unlike gross motor skills, relatively fewer studies have tracked the development of fine motor skills in children with cerebral palsy. This gap is particularly concerning, given the crucial role of fine motor skills in daily activities such as eating, dressing, and writing. To address this knowledge gap, Daher et al. [17] conducted a longitudinal study that followed the fine motor development of children with cerebral palsy over a period of three years. The findings highlighted the heterogeneity of fine motor development in children with cerebral palsy, with some individuals making positive strides while others faced persistent challenges. Consistent with the aforementioned study, Majnemer et al. [18] conducted a longitudinal study that tracked the fine motor development of children with cerebral palsy from infancy to school age. They reported that fine motor skills in this population varied widely, with some children demonstrating improvements over time while others continued to experience significant limitations.

Recent classification of cerebral palsy tends to emphasize functional independence, such as the ability to execute gross and fine motor skills, rather than the underlying motor impairment [19]–[21]. Traditionally, the ability to walk has been touted as the most important gross motor skill for children with cerebral palsy, as it is central to most activities of daily living [16]. Consequently, many assessment tools for gross motor skills in cerebral palsy are based on the ability of affected persons to walk. The Gross Motor Function Classification System [GMFCS] is one such tool used globally to assess gross motor skills in persons with cerebral palsy.

In relation to cross-sectional studies, Twum and Hayford [22] conducted research on the gross motor skills of children with cerebral palsy attending special schools in Ghana. Their study revealed that a significant majority of pupils with cerebral palsy (approximately 80%) achieved higher scores in the GMFCS-E&R [levels I and II]. These pupils demonstrated the ability to perform most gross motor skills, including walking and transitioning in and out of a chair. In contrast, findings from two studies conducted in Nigeria, specifically focusing on gross motor skills, revealed that a significant proportion of children diagnosed with cerebral palsy scored lower on the Gross Motor Function Classification System (GMFCS). In a study by Eseigbe et al. [23], which involved 235 children under the age of 12, over half of the participants were unable to walk independently or with the assistance of a device, placing them at GMFCS-E&R levels IV/V. Similarly, Okeke and Ojinnaka [24] found that a majority of children with cerebral palsy, evaluated for their nutritional status, fell within the lower levels of the GMFCS. Supporting these findings, Chagas et al. [20] concluded that children with cerebral palsy generally experience compromised gross motor skills. Children with lesser limb distribution generally had better gross motor skills compared to their peers with greater limb distribution based on the GMFCS. This finding is corroborated by Himmelmann et al. [25] who discovered that nearly 70% of the total 353 children with cerebral palsy had limited gross motor skills for their respective ages. However, similar studies from other parts of the world based on the GMFCS point to higher scores by children with cerebral palsy. In the Netherlands, a study by [26] that focused on motor growth curves revealed nearly half of all children and young adults with cerebral palsy had no limitation with respect to gross motor skills. Reid et al. [27], in a study that involved using the GMFCS to assess the severity of cerebral palsy, reported up to 61% of persons with cerebral palsy had mild motor impairments [GMFCS levels I/II]. Likewise, Carnahan et al. [28] found that more than 61% of individuals with cerebral palsy were able to walk independently in a study that examined gross and fine motor skills across various subtypes of cerebral palsy. In another study conducted by Tella et al. [29] that focused on evaluating the quality of life of children with cerebral palsy in Nigeria, nearly 70% of the children were reported to be capable of walking independently.

Unlike gross motor skills, fine motor skills in cerebral palsy have not been extensively studied. Twum and Hayford [22] reported on the fine motor skills of pupils with cerebral palsy enrolled in special schools in Ghana. The aforesaid study established that 64% of pupils with cerebral palsy scored in the higher margins of the Manual Ability Classification System (MACS). These pupils could execute most fine motor tasks with speed and accuracy. The aforementioned finding is consistent with that of [28], who compared the gross and fine motor skills of 359 children with cerebral palsy. Of the total number of children in the aforementioned study, 64% were independent concerning fine motor skills in age-relevant functional activities. Similarly, a study by Arner et al. [30] on the hand function of children with cerebral palsy revealed 64% of 367 were independent in age-relevant fine motor skills.

Gross Motor and Fine Motor Skills in the Subtypes of Cerebral Palsy

The gross and fine motor skills of persons with cerebral palsy are largely influenced by the underlying motor impairment and its distribution in the body; hence, it is necessary to include the underlying motor impairment and related topographical distribution in the functional classification of cerebral palsy. Motor impairments are known to be present in about 80% of all children with cerebral palsy [31]. Usually, these motor impairments are classified as spastic, dyskinetic, or ataxic [32], [33]. Dyskinetic cerebral palsy is further subdivided into dystonia and choreo-athetosis. For affected children who exhibit more than one form of motor impairment, the classification is based on the predominant motor impairment [34]. However, Bax et al. [35] assert cerebral palsy should be classified as spastic, dyskinetic or ataxic based on the dominant motor impairment with the listing of any other motor impairment as a secondary type. In affected children where no particular motor impairment is dominant, the condition is termed “mixed” [4]. Indeed, many children with cerebral palsy have mixed presentations [32]. Consequently, the National Institute of Neurological Disorders and Stroke of the United States (NINDS) advocates that identifying the different motor impairments associated with a particular case of cerebral palsy may be of greater use in planning effective motor interventions [36].

Spastic cerebral palsy is the most common form of cerebral palsy, with nearly 80% to 90% of all persons with cerebral palsy exhibiting some level of spasticity [37], [38]. It is characterized by excessive muscle tone as well as resistance to passive movement. The resistance to passive movement tends to increase with increasing velocity of movement [39]. Within the same individual with cerebral palsy, different types of spasticity may exist in different limbs. Damiano et al. [14] asserted the degree and type of spasticity in a child with cerebral palsy may be dependent on the position of the body, fatigue, stress and mood of the child.

The exact relationship between spasticity and motor skills in children with cerebral palsy is equivocal. Himmelmann et al. [25] deduced spasticity in children with cerebral palsy negatively impacted their gross motor skills, was highest during motor activities, and tended to subside or be completely absent during rest. Wright et al. [40] reaffirmed the debilitating effect of spasticity on gross motor skills when they established spasticity adversely influenced gross motor skills in children with cerebral palsy. Using the GMFCS, Eseigbe et al. [23] discovered nearly 70% of children with spastic cerebral palsy required an assistive device for mobility. Similarly, a study by Park [41] reported over 60% of children with spastic cerebral palsy required a handheld mobility device to walk.

On the contrary, Damiano et al. [14] reported there was no significant relationship between spasticity in cerebral palsy and measurements related to gait and concluded spasticity does not necessarily impair gait. Graham and Selber [42] make the argument that gross motor skills in children with spastic cerebral palsy may be more impaired by weakness, difficulties with selective motor control, balance difficulties and challenges with perception than the underlying spasticity. Indeed, a study by Ostensjo et al. [43] concluded selective motor control had a greater limitation on gross motor skills compared to the underlying spasticity in the aforementioned group of children. Similarly, Ross and Engsberg [44] asserted spasticity was minimally related to gross motor deficits in children with spastic cerebral palsy. Shamsoddini et al. [45] make the argument that spasticity has the potential to enhance the gross motor skills of children with cerebral palsy. An elevated muscle tone may be useful in keeping the legs in an upright position during standing. Similarly, the elevated tone in the trunk may support it against gravity and allow for ambulation. Furthermore, spasticity is speculated to help preserve bone mass and density [46].

Arner et al. [30] studied the fine motor skills of children with spastic cerebral palsy using the Manual Ability Classification System (MACS). The fine motor skills of these children varied considerably and were largely dependent on the extent to which the underlying motor impairment affected the upper limbs. However, 54% of children with spastic cerebral palsy could easily handle objects related to daily activities.

Motor impairment in dyskinetic cerebral palsy is characterized by changes in muscle tone, posture and varied involuntary movements. It affects approximately 6%–15% of all children with cerebral palsy [47]. Though not dominant, spasticity may be present in dyskinetic cerebral palsy [25]. The majority of children with dyskinetic cerebral palsy tend to exhibit the dystonic type compared to the choreoathetotic type [48]. Relatively slower, stronger muscular contractions, which may be localized or affect the whole body, are the most distinguishing sign of the dystonic type. Choreoathetotic cerebral palsy is characterized by involuntary muscular contractions, primarily in the face and limbs [47]. Emotional stress or excitement tends to increase the involuntary movement associated with dyskinetic cerebral palsy. On the other hand, involuntary movements tend to abate when affected persons are at rest, asleep or distracted. Affected children tend to have difficulties with sitting, standing and walking due to persistent involuntary movements and rapidly changing muscle tone [48]. Nordmark et al. [49] reported on the gross motor skills of children with dyskinetic cerebral palsy. The authors, in a study spanning three years, reported that 21% of children with dyskinetic cerebral palsy were capable of independent walking. Relative to fine motor skills, Carnahan et al. [28] reported over 60% of children with dyskinetic cerebral palsy had difficulties handling objects. Consistent with this finding, Arner et al. [30] reported that 71% of children with dyskinetic cerebral palsy had limited fine motor skills based on the MACS.

In children with ataxic cerebral palsy, motor impairment mainly occurs in the form of difficulties with balance and coordination. Involuntary movement and tremors in the limbs may be present. Ataxic cerebral palsy is most characterized by tremors that occur during voluntary movement towards a particular target, often termed intention tremors. Usually, these movements involve fine motor skills, such as attempts to write with a pencil or tie a shoe. The tremor progressively worsens as the movement persists and, in other instances, as the hand gets closer to accomplishing the intended task. As a result, children with ataxic cerebral palsy may be unable to complete numerous fine motor activities. It is not uncommon for affected persons to have spasticity in the lower limbs. Ataxic cerebral palsy occurs in only about 4% of all cerebral palsy [50].

Relative to the topographical classification of cerebral palsy, unilateral involvement is termed hemiplegia and accounts for about 33% of all cerebral palsy. In diplegia, there is bilateral involvement affecting primarily the lower limbs. Diplegic cerebral palsy affects approximately 44% of all persons with cerebral palsy. Tetraplegia, also known as quadriplegia, refers to bilateral motor impairment in which the upper limbs are equal or more involved than the lower limbs. Approximately 6% of all persons with cerebral palsy exhibit tetraplegia. Generally, persons with cerebral palsy who exhibit a lesser limb distribution of the underlying motor impairment have superior gross and fine motor skills in contrast with those with greater limb distribution [51].

Relationship Between Motor Skills and Intellectual Functioning

While motor difficulties are the primary characteristic of CP, cognitive impairments are also prevalent, affecting around 30%–50% of individuals [52]. These cognitive impairments can lead to deficits in intellectual functioning. Studies in children with CP have shown deficits in several domains of executive functioning, particularly inhibition and working memory [53], [54]. Attention difficulties are also common in CP, with individuals exhibiting problems with sustained attention, selective attention, and divided attention [55]. Language impairments are observed in approximately 20%–40% of individuals with CP. These impairments can affect various aspects of language, including expressive language, receptive language, and pragmatics [54]. The severity of language difficulties varies depending on the type and severity of CP and the presence of co-occurring conditions. Both short-term and long-term memory can be affected in CP, with deficits in working memory being particularly common [53]. Memory difficulties can impact learning, daily living skills, and overall quality of life [52]. The severity of motor impairment in CP has been shown to be associated with the severity of cognitive deficits [54]. This suggests that the extent of brain injury, which affects both motor and cognitive function, plays a significant role in cognitive development. It is informative to note that the presence of co-morbidities, such as epilepsy, vision or hearing impairments, and feeding difficulties, can further complicate cognitive development in CP [54].

Historically, motor skills and cognition were perceived as separate domains that developed along distinct timescales and under the regulation of different parts of the brain. However, in recent times, evidence from developmental disorders, including cerebral palsy, imaging studies, and typically developing children suggest these two variables could be more closely related than previously thought. Some motor and cognitive processes tend to involve the same brain area, share similar developmental timescales and are underpinned by similar processes of sequencing, monitoring and planning [56], [57]. Furthermore, the three theories underpinning this review, the Dynamic System Theory, Reinvestment Theory, and Embodiment Theory, are inclined towards a relationship between motor skills and intellectual ability. Cerebral palsy is primarily a brain disorder, and the Dynamic System Theory principle that views movement as a product of the interaction between the body, environment and task suggests brain injury could negatively impact motor skills. Reinvestment Theory, on the other hand, suggests pupils with cerebral palsy, especially those with left hemisphere brain injury, are likely to have challenges in adopting explicit motor instructions with the potential for long-term motor skill deficits. Embodiment Theory, by contrast, emphasizes the potential direct relationship between the development of motor skills and the acquisition of intellectual ability.

The bulk of studies focusing on the relationship between motor skills and intellectual ability have focused on typically developing children with contradictory findings. A number of studies focused on the building blocks of motor skills such as strength, balance, coordination, agility and strength. Wassenberg et al. [58] in a study that focused on balance and manual dexterity skills and was limited to 5-to-6-year-olds, reported that overall cognitive ability was not related to motor scores based on correlation analysis. However, in this same study, a specific subset of cognitive ability, working memory and verbal frequency were strongly related to motor skills in girls and boys, respectively. Similarly, Planinsec [59] deduced balance and coordination strongly correlated with cognitive abilities in 5-to-6-year-old boys, while girls of the same age range showed a strong correlation between cognitive ability on the one hand and speed and explosive strength on the other hand. Knight and Rizzuto [60] deduced that balance had a strong correlation with reading and mathematics scores in 7–11-year-old children.

Relative to gross motor skills, Cameron et al. [61] in a longitudinal study that was limited to 3–4-year-old typically developing children, concluded gross motor skills were strongly linked to verbal comprehension. Similarly, Rigoli et al. [62], using typically developing adolescents, concluded gross motor skills were strongly correlated with verbal intelligence. On the contrary, Jenni et al. [63] derived a weak relationship between gross motor skills and intellectual functioning in typically developing individuals between 7 and 18 years. Davis et al. [64] in a study that involved children with cerebellar tumour-related injury, did not find sufficient evidence for a correlation between gross motor skills and intellectual functioning. Similarly, Katic and Bala [65] found no correlation between gross motor skills and the constituents of intellectual functioning in female subjects aged 10–14 years.

On the relationship between fine motor skills and intellectual functioning in typically developing children, Davis et al. [66], in a study involving children 4–11 years old, established a positive correlation between fine motor skills and intellectual functioning. On the contrary, Rigoli et al. [62] did not find sufficient evidence for a relationship between fine motor skills and intellectual functioning. Roebers and Kauer [57] in a study that was limited to 7-year-olds, did not find any evidence for the relationship between fine motor skills and intellectual functioning.

Relative to persons with cerebral palsy, Twum and Hayford [22] in a cross-sectional study of pupils with cerebral palsy aged 5–12 years in Ghana, established that both gross and fine motor skills were predictive of the intellectual ability of pupils with cerebral palsy. Intellectual ability in the aforementioned study was conceptualized as the ability to use verbal abstraction, form discrimination, and quantitative concepts. It is informative to note that most studies examining the relationship between motor skills and intellectual functioning in cerebral palsy have mainly focused on gross motor skills. Huijgen et al. [67] in a systemic review and applying meta-analysis, established gross motor skills in children with cerebral palsy and had a moderate positive correlation with cognitive functioning. Ballester-Plané et al. [68] examined the relationship between gross motor skills and cognitive functioning in persons with dyskinetic cerebral palsy through a case-control design. The authors concluded that more severe gross motor impairments were associated with cognitive deficits in language, attention, visuoperception, and visual memory. In a randomized controlled trial, Chandrashekhar et al. [69] established that higher cognitive functioning was predictive of cerebral palsy children achieving crawling milestones using assisted motion robotic devices. In a cross-sectional study, Al-Nemr and Abdelazeim [70] examined the relationship between gross motor skills and cognitive functioning in the form of attention and executive function in a study limited to 6–12-year-olds with diplegic cerebral palsy. The results revealed positive associations between gross motor skills and the aforementioned facets of intellectual functioning. Similarly, Song [71] deduced that gross motor function was positively correlated with cognitive functioning in 68 children with different types of cerebral palsy. Furthermore, Enkelarr et al. [72] found a positive correlation between motor functioning and intellectual ability in a study that involved 78 toddlers with cerebral palsy.

Several authors have speculated on the potential reasons for the positive association between gross motor skills and intellectual ability of persons with cerebral palsy. Huijgen et al. [67] asserted that improved gross motor skills promote physical activity, which, in turn, can enhance blood flow to the brain and stimulate neuroplasticity, potentially improving cognitive functioning. Martins et al. [73] and Twum and Hayford [22] on the other hand, emphasized that engaging in gross motor activities can provide rich sensory experiences and promote cognitive development through exploration and interaction with the environment.

Relative to fine motor skills, Van Rooije et al. [21] deduced in a longitudinal study that fine motor skills were predictive of early numeracy performance in children with cerebral palsy from 6 to 8 years old. Fragouli et al. [74] explored the relationship between fine motor skills and cognitive functioning in intelligence, attention, working memory, and processing speed. The study established positive correlations between fine motor skills and the aforementioned areas of cognitive functioning. Shaker et al. [75] through a cross-sectional study, established a positive significant correlation between fine motor skills and the following cognitive domains: reaction control, working speed, and working memory. On the contrary, the aforementioned authors established a non-significant correlation between fine motor skills and reaction speed, attention, and logical reasoning.

While the underlying mechanisms behind the relationship between fine motor skills and cognitive functioning are still being explored, some authors make the argument that improved fine motor skills facilitate exploration and interaction with the environment, leading to richer sensory experiences and, subsequently, greater cognitive stimulation [22], [73]. On the other hand, some authors argue that the neural networks governing fine motor skills might also be involved in higher-order cognitive functions like planning, attention, and memory [76].

Vohr et al. [77] conducted a study that explored the correlation between the number of limbs affected by motor impairment and the intellectual ability of children with cerebral palsy. The researchers observed a consistent linear relationship between these variables, except for children with hemiplegic cerebral palsy. Similarly, Russman et al. [78] also noted a general relationship, although not always absolute, between the number of affected limbs in cerebral palsy and the associated intellectual ability.

Conclusion

This current scoping review has provided insights into the development of motor skills in individuals with cerebral palsy [CP], as well as the potential relationship between these motor skills and intellectual functioning. Motor skills development in children with CP was discovered to be heterogeneous. Thus, this review challenges the idea of a single, universal pattern of motor development. Rather, some children experience significant progress in motor skills, while others face persistent challenges. The variability in motor development emphasizes the need to move beyond existing models like the stable limit model (predicting a peak around 5 years followed by stability) and the peak and decline model (predicting a decline after 7 years). It appears the development of motor skills is more nuanced and individualized than previously thought.

Again, the review points to the fact that motor skill development may differ significantly across the different subtypes of CP. Children with spastic, dyskinetic, ataxic, and mixed CP likely exhibit distinct trajectories relative to motor skill acquisition and development.

Another crucial finding is the potential link between both gross and fine motor skills and intellectual functioning in children with CP. This finding points towards a possible role of motor skill development in cognitive processes for individuals with CP.

Recommendations

The findings of the scoping review highlight significant heterogeneity in motor development of motor skills among children with CP. This strongly suggests a need for individualized motor skill intervention plans. Thus, it is imperative therapists and educators assess each child’s specific strengths, weaknesses, and potential for progress to tailor interventions accordingly. Again, while the “stable limit model” suggests a plateau around 5 years, it is crucial to acknowledge that some children may continue to make gains beyond that age. Thus, there is a need for early and ongoing motor skill interventions throughout childhood, with adjustments based on individual progress and potential for continued development. In implementing these motor skills interventions, therapists and educators should be cognizant of the sub-type of cerebral palsy as well as its underlying characteristics so they can tailor their interventions to match their specific needs.

In light of the finding that both gross and fine motor skills could influence the intellectual development of persons with cerebral palsy, it is recommended that assessment of gross and fine motor skills, as well as the intellectual ability of children with cerebral palsy, should be an integral part of their clinical and educational assessment. This is particularly important as an early intervention would potentially improve not only their respective gross and fine motor skills but also their intellectual abilities.

The relationship between motor skills and intellectual ability in persons with cerebral palsy ought to be examined through further longitudinal studies, as the bulk of studies currently available in the literature are cross-sectional in nature. Beyond deducing the exact relationship between motor skills and intellectual ability, longitudinal studies could reveal how motor skills evolves with intellectual ability over time. This could provide better insights into the possible explanations of the underlying mechanisms for this connection while offering a more comprehensive understanding.