Do Exercise Interventions Improve Balance for Children and Adolescents With Down Syndrome? A Systematic Review

Maïano C, Hüe O, Lepage G, Morin AJS, Tracey D, Moullec G. Do exercise interventions improve balance for children and adolescents with Down Syndrome? A Systematic review. Physical Therapy. 2019;99(5):507-518. doi:10.1093/ptj/pzz012

Link to Original Article: https://academic.oup.com/ptj/article/99/5/507/5481826?login=false

Key Points

1. A systematic review was conducted to summarize the effects of exercise interventions on balance in children and adolescents with Down syndrome, with a focus on improving static, dynamic, and static-dynamic balance.

2. The review included eleven studies published between 2010 and 2017, which demonstrated that exercise interventions were more effective than control conditions in improving the static balance of children with Down syndrome and the static-dynamic balance of children and adolescents with Down syndrome.

3. The reviewed exercise interventions showed significant improvements in static and dynamic balance among children with Down syndrome, as well as improvements in the static balance of adolescents with Down syndrome.

4. The studies examined various exercise interventions, including backward walking training, hopscotch, computerized balance training, strengthening exercises, and vibration platform exercises, and found positive effects on balance/postural control.

5. The review highlighted the need for more rigorous studies to confirm the effectiveness of exercise interventions for improving balance in children and adolescents with Down syndrome, including investigation into the most effective types and duration of exercise interventions, as well as the impact on various aspects of balance/postural control.

6. Limitations of the reviewed studies included a small number of studies with high risk of bias, emphasizing the need for future research to provide a more comprehensive understanding of the effects of exercise interventions on balance in youths with Down syndrome.

Introduction

The research literature indicates that individuals with Down syndrome often exhibit deficits in balance and postural control, which can lead to functional limitations and increased risk of falls and injuries. Balance and postural control is the ability to maintain equilibrium in an upright position to avoid falls. It can be assessed in static or dynamic conditions in which static balance refers to the ability to maintain balance when body is motionless and dynamic balance refers to the ability to maintain balance when body is moving or react to perturbation. According to the previous studies, deficits in balance in children with Down syndrome can be explained by hypotonia, which reduces one’s ability to co-activate the muscles along with decreased proprioceptive feedback and hypermobile joints. In typical development, exercise interventions have been found to improve balance and postural control by soliciting neuromuscular components and inducing functional and structural adaptations in the balance system. Various forms of exercise interventions, including balance exercises, virtual reality exercises, muscle strength activities, and sport activities, have been shown to enhance balance and postural performance. However, the effects of exercise interventions specifically designed to improve balance in children and adolescents with Down syndrome have not been systematically reviewed and summarized. This gap in knowledge highlights the need for evidence-based practices to support the design of effective programs aimed at enhancing balance and postural control in youths with Down syndrome. The present article aims to systematically review the effects of exercise interventions designed to improve balance and postural stability in children and adolescents with Down syndrome, with a focus on ages 5 to 22, and to compare these effects with control groups comprising individuals with Down syndrome.

Methods

Data Sources and Searches

The researchers conducted a systematic electronic search across multiple databases and platforms including EBSCO, PsycARTICLES, Scopus, and SPORTDiscus With Full-Text on June 12, 2017, without imposing any year restrictions. They utilized specific search terms grouped into four categories to identify relevant studies related to Down syndrome and balance/postural control in children and adolescents. The search terms encompassed a wide range of keywords related to posture, physical activity, rehabilitation, and youth. The search focused on the title, abstract, and keywords of the studies indexed in the databases. Additionally, the researchers examined the reference lists of the identified studies to uncover any further relevant research. This comprehensive approach allowed them to gather a diverse range of studies to support their investigation.

Study Selection

• Type of studies

This study's selection criteria focused on including only prospective randomized controlled trials (RCTs) or controlled trials, while excluding case studies and non-original studies like reviews and theoretical papers. The participants in the selected studies were required to have Down syndrome and be of school age, defined as 5 to 22 years old. This meant that samples with ages lower than 5 years or higher than 22 years were excluded. Additionally, studies with mixed-age samples were considered eligible if the mean age was below 18 with an age range of 5 to 22 years old, or if results were separately provided for participants younger than 22 years old.

• Type of interventions

The intervention emphasized exercise-based intervention that focus on improving balance in children and adolescents with Down syndrome. The intervention could take in any place, including home, school, clinic, community, and the effects must be compared to control groups also consisting of children and adolescents with Down syndrome.

• Type of outcomes

The researchers only gathered studies that reported outcomes relating to balance and/or postural stability assessed using a clinical test or a posturography.

• Type of publications

The research paper only considered articles that were in-press or published in English in a peer-reviewed journal. When the same sample was used in different publications, only the first publication of an intervention study was included. The eligibility of studies was assessed according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA) by the first 2 authors. Initially, the authors independently assessed the titles and abstracts of the articles, followed by an independent assessment of the full text of the studies retained in the previous step. Any discrepancies in their results were then discussed to reach a consensus.

Data Extraction and Quality Assessment

• Data extraction

The data extraction process involved the independent extraction of 10 categories of information from each included study, including country and geographic region, study design, recruitment setting, sample age category, intellectual disability level, characteristics of the exercise intervention and control groups, description of the exercise intervention program and control condition, characteristics of balance measures, and within-and between-group differences in balance measures.

• Quality assessment

Quality assessment was carried out by independently assessing the risk of bias in the studies using the Cochrane Collaboration tool, which measures random sequence generation, allocation concealment, masking of participants and personnel, masking of outcome assessment, incomplete outcome data, and selective reporting. Each item was rated as low risk of bias, high risk of bias, or unclear risk of bias. Discrepancies in ratings were resolved by the authors.

Data Synthesis and Analysis

The Data Synthesis and Analysis section of the research paper presents a comprehensive overview of the findings on balance parameters. The results are organized in a tabular format for each study, focusing on the changes in balance parameters between the pretest and posttest in both the intervention and control groups. The researchers report on whether there were significant improvements in balance parameter scores within each group and whether there were significant differences in posttest scores between the intervention and control groups. Additionally, they assess whether the pretest-posttest change in balance parameters scores significantly differed between the two groups.

The results pertaining to static, dynamic, and static-dynamic balance are then discussed separately for studies involving children and adolescents. The narrative synthesis highlights the number of studies that demonstrated statistically significant differences in posttest scores or pretest-posttest change in balance parameters between the intervention and control groups. Furthermore, the researchers analyze the number of studies showing improvement in balance parameter scores between the pretest and posttest in both groups.

Role of the Funding Source

The Role of the Funding Source section of the research paper outlines the financial support received from the Social Sciences and Humanities Research Council of Canada (SSHRC) and the Australian Research Council (ARC). The grants from SSHRC (430-2012-0091, 435-2014-0909) were awarded to the first, second, fourth, and fifth authors, while the grant from ARC (DP140101559) was awarded to the first, fourth, and fifth authors. Importantly, the section explicitly states that the funding sources SSHRC and ARC had no role in the study design, data collection, analysis, interpretation, manuscript writing, or the decision to submit the paper for publication. This declaration is crucial in affirming that the research was conducted independently and without any undue influence from the funding bodies. It underscores the integrity and autonomy of the research process, ensuring that the findings and conclusions are based solely on the merits of the research itself. Furthermore, by stating the lack of involvement of the funding sources in the various stages of the research, the section serves to maintain transparency and integrity in the reporting of the study. Overall, the Role of the Funding Source section underscores the independence and impartiality of the research, safeguarding against potential conflicts of interest and upholding the credibility of the findings.

Results

Selection of the Studies

The study identified 659 articles, which reduced to 353 after removing duplicates. After analyzing titles and abstracts, 331 articles were excluded for not meeting the inclusion criteria. Full texts of the 22 remaining articles were screened, resulting in the exclusion of 11 publications that also did not meet the criteria. This left 11 studies, published between 2010 and 2017, that met the inclusion criteria, with most focusing on children with Down syndrome. These studies are summarized in a table. The studies mentioned details such as the intervention setting, adaptability of the intervention during the trial, and strategies used to ensure intervention conformity. In half of the studies involving children, the control group followed a conventional or designed physical therapy program, while in studies involving adolescents, the control condition was detailed in only one study (regular school activities). This process allowed the researchers to select 11 relevant studies for further analysis and laid the groundwork for the subsequent phases of the research.

Characteristics of the Reviewed Studies

The Characteristics of the Reviewed Studies section of the research paper provides an overview of the measures and methods used in various studies assessing balance in children and adolescents with Down syndrome. Among the studies focusing on children, 5 out of 8 assessed dynamic balance, 1 assessed static balance, 1 assessed both static and dynamic balance, and 1 assessed static-dynamic balance. For adolescents, 2 studies assessed static balance and 1 assessed static-dynamic balance. Static balance was evaluated using posturography apparatus or clinical tests such as the Stork Test, while dynamic balance was assessed using posturography apparatus or clinical balance tests like the Heel-to-Toe Dynamic Balance Test and the Timed "Up & Go" Test. Studies examining static-dynamic balance used the balance subscale of the Bruininks-Oseretsky Test of Motor Proficiency. Measurements of balance included stability index scores, path length covered by the center of gravity, time spent within a radius circle, center of pressure velocity, and root-mean-square error for studies using posturography. Clinical tests measured balance using standing time, test performance time, number of steps, and scores obtained with the BOTMP. This section outlines the diverse measures and methods used in studies assessing balance in children and adolescents with Down syndrome, providing insight into the specific assessments and techniques employed across the reviewed studies.

Effects of Exercise Interventions

The research paper presents the effects of exercise interventions on children and adolescents. In children, all studies showed that exercise intervention groups had significantly higher post-test static, dynamic, and static-dynamic balance values compared to control groups. Furthermore, there was a statistically significant improvement in dynamic balance for the control groups as well. For adolescents, none of the randomized controlled trials (RCTs) found or reported post-test differences in static balance between groups, but one study reported that the intervention group had significantly higher pretest-posttest change values in static-dynamic balance than the control group. Additionally, two studies focusing on adolescents reported a statistically significant improvement in static balance in the exercise intervention groups, while none of the studies reported a statistically significant improvement in static balance for the control groups. The results reflect the positive impact of exercise interventions on balance in both children and adolescents, with greater improvements noted in dynamic balance for children and static-dynamic balance for adolescents. These findings underscore the potential benefits of exercise interventions in enhancing balance performance in pediatric populations.

Quality Assessment of the Reviewed Studies

The research paper indicates a high risk of bias and unclear risk of bias were found in all of the 11 studies.

Discussion

The research paper conducted a systematic review on exercise interventions aimed at improving balance in children and adolescents with Down syndrome. The reviewed studies demonstrated that exercise interventions had positive effects on static, dynamic, and static-dynamic balance in children with Down syndrome, with significant improvements observed post-intervention. However, the effects on static balance in adolescents were not significantly different from control conditions. The findings suggested that exercise interventions improved the ability of children and adolescents with Down syndrome to compensate for sensory deficiencies in balance and postural stability. The paper identified the need for more comprehensive studies to determine the most effective type, duration, and frequency of exercise interventions for improving balance in this population. It also highlighted the lack of information on the nature of exercise interventions and the need for improved methodology and reporting in future studies. Additionally, the paper underscored the limited number of studies and their geographical restrictions as limitations, emphasizing the necessity for further rigorous research to gain a comprehensive understanding of the topic.

Conclusion

The research paper concludes that exercise interventions are more effective than control conditions in improving static and static-dynamic balance in children with Down syndrome. Similarly, exercise interventions are found to be more effective in improving static-dynamic balance in adolescents with Down syndrome. However, the findings regarding dynamic balance in children and static balance in adolescents are inconclusive. The authors emphasize that the limited number of studies and their high risk of bias necessitate caution in interpreting the findings. They recommend that future research should rigorously and systematically examine the effect of exercise interventions on balance outcomes. Additionally, the paper highlights the need for more detailed exercise interventions and improved reporting practices to assist professionals in selecting, developing, and implementing interventions to enhance the physical health of youths with Down syndrome.

Opportunities for Future Research

1. Investigate the long-term effects of exercise interventions on the balance/postural stability of children and adolescents with Down syndrome to determine the duration and frequency needed to achieve sustainable improvements.

2. Compare different types of exercise interventions (balance exercises, strengthening, vibration platform, etc.) to determine their relative effectiveness in improving balance/postural control among youths with Down syndrome, providing guidance for the design of more targeted and effective intervention programs.

3. Examine the effects of exercise interventions on specific balance challenges, such as standing on one leg or when visual cues or plantar cutaneous sensitivity is disturbed, to understand the broader impact of interventions and improve their specificity.

4. Conduct studies in diverse geographic regions to assess the generalizability of the findings and to understand potential cultural or environmental influences on the effectiveness of exercise interventions for improving balance in youths with Down syndrome.

5. Address the methodological weaknesses identified in the reviewed studies, such as concealed allocation, masking of participants and assessors, and reporting biases, to improve the quality of future research and ensure robust and reliable findings.

6. Explore the potential impact of exercise interventions on the broader well-being and functional capacity of children and adolescents with Down syndrome, incorporating measures beyond balance/postural control to provide a more comprehensive understanding of the benefits of interventions.