Associations of Motor Performance and Executive Functions: Comparing Children with Down Syndrome to Chronological and Mental Age-Matched Controls

Effectiveness of dynamic neuromuscular stabilization training on strength, endurance, and flexibility in adults with intellectual disabilities, a randomized controlled trial

Individuals with intellectual disabilities (ID) often exhibit lower levels of physical fitness compared to the general population, including reduced strength, endurance, flexibility, and coordination. Dynamic neuromuscular stabilization (DNS) training can potentially improve the performance of adults with ID caused by weak motor skills due to a lack of desirable nerve growth during childhood and before puberty. Also, DNS training proposed to improve physical fitness in this population, but the effectiveness and durability of DNS training on specific fitness components have not been well-established. This study employed a randomized controlled trial design to investigate the effects of an 8-week DNS training program on the strength, endurance, and flexibility of adults with ID. A total of 31 participants were randomly assigned to either an intervention group (n = 16) or a control group (n = 15). Muscular strength, endurance, and flexibility were assessed at baseline (pre-test), immediately after the intervention (post-test), and 2 months following the intervention (follow-up) using the 30-second chair stand (30sCS) test, sit-ups test, trunk lift test, and chair sit-and-reach test. Participants in the intervention group engaged in the DNS training program for 8 weeks, with 3 sessions per week, while the control group maintained their usual activities. The analysis of the outcome measures revealed significant time, group, and time-group interaction effects. Post-hoc analyses indicated that the DNS group exhibited significantly greater improvements in 30sCS, sit-ups, trunk lift, and chair sit-and-reach compared to the control group (p < 0.01). These improvements were maintained at the 2-month follow-up assessment in the DNS group. This randomized controlled trial demonstrates that an 8-week DNS training program significantly improves muscular strength, endurance, and flexibility in adults with ID, with benefits maintained at a 2 month follow-up. Further research is needed to replicate these findings and investigate underlying mechanisms, but the study highlights the potential of DNS training to promote physical fitness and well-being in individuals with ID.Trial registration RTC, prospectively registered in the Clinical Trial Registry (UMIN000053560) on 24/03/2024.

Associations Between Motor Competence and Executive Functions in Children and Adolescents: A Systematic Review and Meta-analysis

BACKGROUND

Motor competence and executive functions co-develop throughout childhood and adolescence, and there is emerging evidence that improvements in motor competence may have cognitive benefits in these populations. There is a need to provide a quantitative synthesis of the cross-sectional, longitudinal and experimental studies that have examined the association between motor competence and executive functions in school-aged youth.

OBJECTIVES

The primary aim of our systematic review was to synthesise evidence of the association between motor competence and executive functions in school-aged children and adolescents (5-18 years). Our secondary aim was to examine key moderators of this association.

METHODS

We searched the PubMed, PsycINFO, Scopus, Ovid MEDLINE, SPORTDiscus and EMBASE databases from inception up to 27 June 2023. We included cross-sectional, longitudinal and experimental studies that assessed the association between motor competence (e.g., general motor competence, locomotor skills, object control skills and stability skills) and executive functions (e.g., general executive functions, inhibition, working memory and cognitive flexibility) in children and adolescents aged 5-18 years.

RESULTS

In total, 12,117 records were screened for eligibility, and 44 studies were included. From the 44 included studies, we meta-analysed 37 studies with 251 effect sizes using a structural equation modelling approach in the statistical program R. We found a small positive association (r = 0.18, [95% confidence interval (CI) 0.13-0.22]) between motor competence and executive functions. The positive associations were observed in cross-sectional (r = 0.17, [95% CI 0.13-0.22]), longitudinal (r = 0.15, [95% CI 0.03-0.28]) and experimental studies (r = 0.25, [95% CI 0.01-0.45]). We also found that general motor competence (r = 0.25, [95% CI 0.18-0.33]), locomotor (r = 0.15, [95% CI 0.09-0.21]), object control (r = 0.14, [95% CI 0.08-0.20]) and stability (r = 0.14, [95% CI 0.08-0.20]) skills were associated with executive functions. We did not find any moderating effects for participants' age on the associations between motor competence and executive functions.

CONCLUSIONS

Our findings suggest a small-to-moderate positive association between motor competence and executive functions in children and adolescents. The small number of experimental studies included in this review support the assertion that interventions targeting children's motor competence may be a promising strategy to improve their executive functions; however, more research is needed to confirm these findings. Future studies should explore the underlying mechanisms linking motor competence and executive functions as their comprehension may be used to optimise future intervention design and delivery.

PROSPERO REGISTRATION

CRD42021285134.

Impact of Prescribed Exercise on the Physical and Cognitive Health of Adults with Down Syndrome: The MinDSets Study

The duplication of chromosome 21, as evidenced in Down Syndrome (DS), has been linked to contraindications to health, such as chronotropic and respiratory incompetence, neuromuscular conditions, and impaired cognitive functioning. The purpose of this study was to examine the effects of eight weeks of prescribed exercise and/or cognitive training on the physical and cognitive health of adults with DS. Eighty-three participants (age 27.1 ± 8.0 years) across five continents participated. Physical fitness was assessed using a modified version of the six-minute walk test (6MWT), while cognitive and executive functions were assessed using the Corsi block test, the Sustained-Attention-To-Response Task (SART), and the Stroop task (STROOP). All were completed pre- and post-intervention. Participants were assigned to eight weeks of either exercise (EXE), 3 × 30 min of walking/jogging per week, cognitive training (COG) 6 × ~20 min per week, a combined group (COM), and a control group (CON) engaging in no intervention. 6MWT distance increased by 11.4% for EXE and 9.9% for COM (p < 0.05). For SART, there were positive significant interactions between the number of correct and incorrect responses from pre- to post-intervention when participants were asked to refrain from a response (NO-GO-trials) across all experimental groups (p < 0.05). There were positive significant interactions in the number of correct, incorrect, and timeout incompatible responses for STROOP in EXE, COG, and COM (p < 0.05). Walking generated a cognitive load attributed to heightened levels of vigilance and decision-making, suggesting that exercise should be adopted within the DS community to promote physical and cognitive well-being.

Fundamental motor skill proficiency among 7- to 10-year-old children with Down syndrome

[Purpose] The purposes of this study were to assess the fundamental motor skill (FMS) of children with Down syndrome (DS) and to compare their FMS proficiencies to those of chronological age-matched and gender-matched typically developing children (TDC). [Participants and Methods] This cross-sectional study involved a total of 60 participants (30 children with DS and 30 TDC). The FMS proficiency of participants was assessed by using the test of gross motor development, second edition (TGMD-2). The data were analyzed using independent samples t-tests to verify the differences between the two groups and gender. The effect size of Cohen's d was also determined for comparing the two groups. [Results] The results showed that there were significant differences between children with DS and the TDC on locomotor and object control standard scores, and the gross motor quotient (GMQ). However, there were no significant gender-based differences in the locomotor and object control standard scores and the GMQ in both groups. [Conclusion] Based on the current results, the FMS proficiency of children with DS is lower than the TDC. Therefore, a therapeutic intervention program is necessary for children with DS to improve their FMS proficiency.