Increased Anterior Pelvic Angle Characterizes the Gait of Children with Attention Deficit/Hyperactivity Disorder (ADHD)

Gait in children with and without ADHD: A systematic literature review

BACKGROUND

There is increasing speculation whether Attention-Deficit/Hyperactivity Disorder (ADHD) has phenotypic or secondary motor symptoms. Some evidence suggests even fundamental motor skills such as walking can differ in ADHD, however, the evidence is limited and has not been reviewed. Therefore, we conducted a systematic review to summarize the findings regarding gait in ADHD compared to typically developing children in (1) normal (i.e., self-paced), (2) paced or complex (i.e., walking backwards), and (3) dual-task contexts.

METHOD

Following a thorough literature search and application of stringent exclusion criteria, a total of 12 studies were included in this review. All studies examined normal walking with a variety of gait parameters in children (age range: 5-18), however, selected parameters and group differences were often inconsistent.

RESULTS

In self-paced walking, studies reporting gait with coefficients of variance (CVs) indicated several between-group differences, whereas averages of gait variables were the same for those with ADHD and typically developing children. Paced or complex walking contexts often differed between ADHD and typically developing groups, favoring the ADHD group in some cases, but primarily the typically developing participants. Finally, walking contexts with dual-tasks showed more frequent performance losses in the ADHD group.

DISCUSSION

Children with ADHD seem to have specific patterns of gait variability compared to typically developing children, particularly in complex walking contexts and at faster paces. The influence of age, medication, and method of gait normalization may have influenced the results of studies. Overall, this review highlights the potential for a unique gait profile in children with ADHD.

Do Children with Attention Deficit and Hyperactivity Disorder Present with Different Spatio-Temporal Gait Parameters? An Evaluation of the Relationship Between Gait and Gross Motor Skills

Objective

The aim of the current study was to compare the spatio-temporal parameters of gait and gross motor skills in children with attention deficit hyperactivity disorder-combined type with those of typically developing children and to search the effect of motor skills on gait parameters in children with attention deficit hyperactivity disorder-combined type.

Methods

A total of 50 children (n = 25 attention deficit hyperactivity disorder-combined type, n = 25 typically developing children) aged 5-12 years were included. Gross motor skills were evaluated using the Bruininks-Oseretsky Test Second Edition-Short Form. Spatio-temporal parameters of gait were assessed with a GAITRite^® computer-based system.

Results

In the subtests of Bruininks-Oseretsky Test Second Edition-Short Form (bilateral coordination (P < .001), balance (P = .013), running speed and agility (P = .003)), lower scores were obtained by the children with attention deficit hyperactivity disorder-combined type. The swing phase of gait was found to be longer in children with attention deficit hyperactivity disorder-combined type (P = .01).

Conclusion

The current study results show that gross motor skills are affected negatively and the swing phase is prolonged in children with attention deficit hyperactivity disorder-combined type. Upper limb coordination and balance were also seen to have an effect on the velocity, step, and stride length. It is important to include an objective gait assessment as well as gross motor skills in the comprehensive clinical evaluation of children with attention deficit hyperactivity disorder-combined type.

The investigation of foot structure within children who have attention-deficit hyperactivity disorder: a case-controlled study

The impairments in motor performance could be related to the foot structure in children with attention-deficit/hyperactivity disorder (ADHD) while considering the close relationship between foot structure and lower extremity alignment. This study aimed to investigate the foot structure and its relationships between disease severity, physical activity and psychiatric traits in children with ADHD. Children with ADHD (n = 50; mean age: 12.02 ± 1.83 years) and typically developing peers (n = 30; mean age: 12.86 ± 2.56 years) were included. The static footprint analysis was collected by using digital images. The ImageJ program was used to calculate Clarke's angle, Staheli arch index (SAI) and Chippaux-Smirak index (CSI). The Turgay DSM-IV disruptive behavior disorders rating scale (T-DSM-IV-S), physical activity questionnaire for older children (PQ-C), children's depression inventory and state-trait anxiety inventory for children were all used to assess symptoms of ADHD, physical activity, depression, stress and anxiety, respectively. Approximately 52-53% of children with ADHD had mild to severe flatfoot, while only 8-13% of typically developing peers had flatfoot based on SAI and CSI (P = 0.01). Significant correlation was found between Clarke's angle and PQ-C (r = 0.21, P = 0.04). Besides, T-DSM-IV-S was significantly correlated with SAI (r = 0.24, P = 0.01) and CSI (r = 0.25, P = 0.01) in children with ADHD. Children with ADHD had a significantly greater tendency of flatfoot compared to typically developing peers. Besides, the deterioration of the foot structure of children with ADHD was associated with disease severity.

Gait control in children with attention-deficit/hyperactivity disorder

The current profile of gait control in children with ADHD is incomplete and predominately based on children walking forward at a self-selected pace. There are no studies of potential gait deficits in this clinical population when walking in different directions in combination with varying rates of stepping that are freely selected and entrained to an external stimulus. The purpose of the current study was to address this lack of information by assessing gait of children aged 7-17 years with (n = 17) and without (n = 26) ADHD. Participants walked forward and backward along an electronically instrumented carpet at a self-selected stepping rate and in synchrony to a metronome that dictated an increased and decreased stepping rate. Using repeated measures analysis of covariance (ANCOVA) to assess spatiotemporal gait parameters, results showed that children with ADHD exhibited a significantly exaggerated, toes 'turned out,' foot position for all walking conditions compared to typically developing children. When walking backward, children with ADHD produced an increased step width, higher stepping cadence, and increased velocity. Additionally, coefficient of variation ratios indicated that children with ADHD produced greater variability of velocity, cadence, and step time for all walking conditions, and greater variability for stride length when walking at an increased stepping rate. Results were interpreted in terms of clinical significance and practical ramifications that inform rehabilitation specialists in designing therapies that ameliorate the reported gait deficits.

Dissociation of impulsivity and aggression in mice deficient for the ADHD risk gene Adgrl3: Evidence for dopamine transporter dysregulation

Adhesion G protein-coupled receptor L3 (ADGRL3, LPHN3) has putative roles in neuronal migration and synapse function. Various polymorphisms in ADGRL3 have been linked with an increased risk of attention deficit/hyperactivity disorder (ADHD). In this study, we examined the characteristics of Adgrl3-deficient mice in multiple behavioural domains related to ADHD: locomotive activity, impulsivity, gait, visuospatial and recognition memory, sociability, anxiety-like behaviour and aggression. Additionally, we investigated the effect of Adgrl3-depletion at the transcriptomic level by RNA-sequencing three ADHD-relevant brain regions: prefrontal cortex (PFC), hippocampus and striatum. Adgrl3^-/- mice show increased locomotive activity across all tests and subtle gait abnormalities. These mice also show impairments across spatial memory and learning domains, alongside increased levels of impulsivity and sociability with decreased aggression. However, these alterations were absent in Adgrl3^+/- mice. Across all brain regions tested, the numbers of genes found to exhibit differential expression was relatively small, indicating a specific pathway of action, rather than a broad neurobiological perturbation. Gene-set analysis of differential expression in the PFC detected a number of ADHD-relevant pathways including dopaminergic synapses as well as cocaine and amphetamine addiction. The Slc6a3 gene coding for the dopamine transporter was the most dysregulated gene in the PFC. Unexpectedly, several neurohormone/peptides which are typically only expressed in the hypothamalus were found to be dysregulated in the striatum. Our study further validates Adgrl3 constitutive knockout mice as an experimental model of ADHD while providing neuroanatomical targets for future studies involving ADGRL3 modified models. This article is part of the Special Issue entitled 'Current status of the neurobiology of aggression and impulsivity'.

Catechol-O-methyltransferase polymorphism is associated with the cortico-cerebellar functional connectivity of executive function in children with attention-deficit/hyperactivity disorder

The cerebellum, although traditionally considered a motor structure, has been increasingly recognized to play a role in regulating executive function, the dysfunction of which is a factor in attention-deficit/hyperactivity disorder (ADHD). Additionally, catechol-O-methyltransferase (COMT) polymorphism has been reported to be associated with executive function. We examined whether the cortico-cerebellar executive function network is altered in children with ADHD and whether COMT polymorphism is associated with the altered network. Thirty-one children with ADHD and thirty age- and IQ-matched typically developing (TD) controls underwent resting-state functional MRI, and functional connectivity of executive function-related Crus I/II in the cerebellum was analysed. COMT Val158Met genotype data were also obtained from children with ADHD. Relative to TD controls, children with ADHD showed significantly lower functional connectivity of the right Crus I/II with the left dorsolateral prefrontal cortex. Additionally, the functional connectivity of children with ADHD was modulated by COMT polymorphism, with Met-carriers exhibiting significantly lower functional connectivity than the Val/Val genotype. These results suggest the existence of variations, such as ethnic differences, in COMT genetic effects on the cortico-cerebellar executive function network. These variations contribute to heterogeneity in ADHD. Further neuroimaging genetics study might lead to the development of fundamental therapies that target ADHD pathophysiology.