Gait characteristics in individuals with intellectual disabilities: a literature review

Effects of a dual-task activity on gait parameters of people with and without intellectual disabilities

BACKGROUND

The main objective of this study was to evaluate gait parameters in people with intellectual disability (ID) and without intellectual disability (WID) in two different walking conditions [single task vs. dual task (DT)]. A secondary aim was to evaluate the dual-task cost (DTC) that the DT causes in each group.

METHODS

A total of 119 participants joined in this study: 56 ID (30 men) and 63 WID (30 men). The OptoGait system was used to assess gait. In addition, Witty photocells were added to assess gait under the DT condition.

RESULTS

Single support time was lower for participants with ID (P < 0.01), while double support time was higher (P < 0.05). All coefficients of variation for gait parameters were higher in participants with ID. Additionally, changes in gait were observed in both groups during the DT condition compared with the single-task condition. These changes were larger for participants with ID in step length, double support time and gait speed (P < 0.001), resulting in a higher DTC in these variables in the ID group (P < 0.01).

CONCLUSIONS

Both groups reduced gait performance in the DT condition. However, greater gait variability occurred in the ID group. In addition, DTC was higher for the ID group in all variables analysed. Therefore, people with ID show worse gait performance during a DT than people WID.

Different types of combined training programs to improve postural balance in single and dual tasks in children with intellectual disability

The study explored the effects of two combined training (Strength-Proprioceptive versus Cognitive-Balance) programs on postural balance during single-task and dual-task conditions in children with intellectual disability. The postural balance and the second cognitive-task performances were evaluated before and after 8-week of training in two groups: Strength-Proprioceptive Group (n = 12) and Cognitive-Balance Group (n = 10). Results showed that, in both groups and regardless of the training effect, the postural balance performance was significantly (p < 0.05) altered in the dual-task condition compared to the single-task one. After-training session, postural balance performance was improved significantly (p < 0.001) for all task conditions. After training session, the second cognitive-task performance was improved in the Strength-Proprioceptive Group (p < 0.001) and Cognitive-Balance Groupe (p < 0.05). In conclusion, the combined training programs, Strength-Proprioceptive and Cognitive-Balance, improved postural balance performance in single-task and dual-task conditions in children with intellectual disability.

Effect of Yoga of Adaptive Yogasana Practice on the Flexibility and Psychomotor Variables in Intellectually Disabled Subjects

Intellectual disability (ID) is a public health challenge affecting communities worldwide. ID is characterized by impaired physical and cognitive functioning and less engaged in physical activities. The objective of this study was to assess the impact of adaptive yoga practices on cognitive and motor abilities in the subjects with ID. Sixty-six subjects with mild and moderate IDs were purposively selected and randomly divided into experimental and control groups, with 33 subjects in each group. One month of adaptive yoga module was provided to the experimental group. To assess the impact of the yoga intervention, Functional Reach Test (FRT), Wall Toss Test (WTT), Finger Tapping Test (FTT), Sit-Reach Test (SRT), and Six Letter Cancellation Test (SLCT) were administered. The experimental group showed a statistically significant improvement with P < 0.05 across all the parameters, whereas the control group could not observe a significant improvement. Based on the results, this study concludes that "one month of adaptive yoga module" delivered impact and helped to improve the dynamic balance, eye-hand coordination, neuro-motor function, spinal flexibility, and selective attention in ID-afflicted subjects.

What are the views of adults with an intellectual disability (AWID), carers and healthcare professionals on a community falls management programme for AWID: a qualitative interview study in the UK

OBJECTIVES

The aim of this study was to refine a draft of the ACTiON FALLS LD programme based on the views of adults with an intellectual disability (AWID), carers and healthcare professionals (HCPs).

DESIGN, SETTING AND PARTICIPANTS

The semistructured interview study included HCP as well as AWID and carers supporting AWID living in the community. Community settings included sheltered living, supported living, AWID living at home with family carers or independently. The interview study explored the first draft of the ACTiON FALLS LD programme as well as the wider falls management for AWID. Interviews with AWID were developed to include a range of approaches (eg, case studies, pictures) to support inclusive participation. Individual interviews were digitally recorded and transcribed. Researcher notes were used during interviews with AWID. All data were analysed using the principles of framework analysis.

RESULTS

14 HCP, 8 carers and 13 AWID took part in the interview process. Five key themes were identified: programme components, programme design, programme approach, who would use the programme and programme delivery.

CONCLUSIONS

The views of AWID, HCP and carers showed the need to consider the impact of risk perception, anxiety and fear of falling in the adaption of the ACTiON FALLS programme. The programme needs to be accessible and support the inclusion of AWID in managing falls and ultimately fulfil the requirement for a proactive and educational tool by all.

Neuromuscular control of masticatory muscles in people with intellectual disability, middle-aged adults and older adults

BACKGROUND

Motor control issues are common for people with intellectual disabilities (PWID), resulting in difficulties with basic activities of daily living, including eating. Mastication, which is crucial for digestion and overall health, is poorly understood in this population. PWID shows frailty similar to older people, highlighting the importance of comparing masticatory motor control with older adults. This study compared the neuromuscular control of the masticatory muscles in middle-aged, PWID and older adults.

METHODS

A cross-sectional analytical design was used. During the mastication task of a carrot piece (2 cm in diameter and weighing 0.5 g), surface electromyography was used to record muscle activity patterns from the right and left masseter and temporalis muscles. Principal component analysis (PCA) was used to assess neuromuscular control. A z-score normalisation of the first component's variance from PCA to identify those individuals with altered neuromuscular control. A mixed ANOVA was performed to assess the interaction between principal components, groups and body composition.

RESULTS

Thirty PWIDs (aged 35-55 years), middle-aged adults and 32 older adults were recruited. PWID and older adults showed decreased neuromuscular control of the masticatory muscles compared to middle-aged control adults (P < 0.05). PWID had the highest proportion of individuals with altered neuromuscular control of the masticatory muscle (53%) compared to older adults (19%) and middle-aged adults (0%) (P < 0.05).

CONCLUSIONS

Our results indicate that PWID and older adults have reduced neuromuscular control compared to middle-aged adults. Notably, a significant proportion of the PWID showed altered masticatory muscle control compared to older adults. Further research is needed to explore the potential benefits of masticatory muscle training for PWID.

Walking activity increases physical abilities and subjective health in people with seven different types of disabilities

Introduction

People with disabilities have a great risk of physical inactivity, which causes several diseases, dependency, and long-term care. Walking helps to increase physical activity, which leads to better overall health and independence. However, less research attention has focused on walking for people with disabilities, and even fewer studies have been considered for different types of disabilities. The present study aimed to demonstrate how walking distance was associated with people with seven different types of disabilities- including visual, hearing, physical/mobility, intellectual, learning, autism, and emotional/behavioral disabilities-in terms of their physical abilities and subjective health.

Methods

A total of 378 participants (aged 13-65) were gathered from seven national organizations in Thailand. A survey questionnaire on aspects of physical abilities (i.e., walking distance or manually rolling wheelchair distance; body balance; weightlifting; exercise duration and frequency); and subjective health (i.e., health status and satisfaction) was completed online by all participants.

Results

The walking distance was partially positive and associated with exercise duration, weightlifting, exercise frequency, and health status (all p values < 0.001), as well as body balance and health satisfaction (p = 0.001 and 0.004, respectively), after controlling for age, sex, and types of disability. This demonstrated that increasing the amount of distance walked could well lead to a more positive body and mind.

Discussion

The present study suggests that the possibility of having a walk and/or encouraging people with disabilities to walk for greater distances can have a significant impact on both their physical and subjective health outcomes.

Comparison of Dynamic Balance Performances of Adult Runners With Intellectual Disability Versus Their Sedentary Peers

Our aim in this study was to compare the dynamic balance between runners (100 sprint) and non-runners with intellectual disability (ID). Our participants were 36 healthy male adults with ID aged 17-29 years, divided into runners (n = 18) and sedentary non-runners (n = 18). We assessed dynamic balance in these participants, using the Y-Balance Test (YBT), the Expanded-Timed Up and Go Test (ETUGT) and the Functional Reach Test (FRT). Runners with ID had significantly better balance scores than their sedentary counterparts on YBT (p < .001), the two walking phases of the ETUGT (p < .05) and the FRT (p <.05). Thus, running training (100 m sprint) was associated with better dynamic balance in this sample.

The Usefulness of a Targeted Next Generation Sequencing Gene Panel in Providing Molecular Diagnosis to Patients With a Broad Spectrum of Neurodevelopmental Disorders

Background: Neurodevelopmental disorders comprise a clinically and genetically heterogeneous group of conditions that affect 2%–5% of children and represents a public health challenge due to complexity of the etiology. Only few patients with unexplained syndromic and non-syndromic NDDs receive a diagnosis through first-tier genetic tests as array-CGH and the search for FMR1 CGG expansion. The aim of this study was to evaluate the clinical performance of a targeted next-generation sequencing (NGS) gene panel as a second-tier test in a group of undiagnosed patients with NDDs.

Method: A 221-gene next-generation sequencing custom panel was designed and used to analyze a cohort of 338 patients with a broad spectrum of NDDs (202 males and 136 females) including Intellectual Disability (ID), Autism Spectrum Disorders (ASD), Epilepsy, language and motor disorders.

Results: A molecular diagnosis was established in 71 patients (21%) and a de novo origin was present in 38 (64.4%) of the available trios. The diagnostic yield was significantly higher in females than in males (29.4% vs. 15.3%; p = 0.0019) in particular in ASD (36.8% vs. 7.6%; p = 0.0026) and Epilepsy (38.9% vs. 14.4% p = 0.001). The most involved genes were SLC2A1, SCN1A, ANKRD11, ATP1A2, CACNA1A, FOXP1, and GNAS altered in more than two patients and accounting for the 19.7% of the diagnosis.

Conclusion: Our findings showed that this NGS panel represents a powerful and affordable clinical tool, significantly increasing the diagnostic yield in patients with different form of NDDs in a cost- and time-effective manner without the need of large investments in data storage and bioinformatic analysis.

Postural balance problems in people with intellectual disabilities: Do not forget the sensory input systems

BACKGROUND

This pilot study aimed to explore the impact of visual, auditory and vestibular dysfunctions on the postural balance performance in adults with intellectual disabilities. Additionally, a comparison was made between the subjects with intellectual disabilities and a control group concerning static and dynamic balance tasks.

METHOD

Thirty adults with intellectual disabilities and 25 control subjects received a postural balance assessment. Additionally, the experimental group was subjected to a visual, auditory and vestibular screening.

RESULTS

The experimental group performed significantly worse and/or showed more sway compared to the control group for all balance tasks (p < .01) except the timed up and go test. Within the experimental group, a significant positive correlation (r_s (24) = 0.513, p = .007) was observed between the number of failed sensory screening items and the number of failed balance tasks.

CONCLUSIONS

These findings suggest significant involvement of peripheral sensorial deficits in the balance problems that people with intellectual disabilities often experience.

Biomechanical analysis of gait patterns in children with intellectual disabilities

BACKGROUND

Children with intellectual disabilities (ID) typically master walking skills much later than typically developing (TD) children and have poor postural control ability. This study aimed to explore the gait ability and characteristics of children with ID and whether there is any difference in walking ability between them and TD children.

METHOD

In this study, integrating kinematic-biomechanic-dynamic measurement methods and corresponding analysis methods (video analysis, three-dimensional force analysis and electromyography test analysis) were used to characterise and compare the gait patterns between ID children and TD children.

RESULTS

ID children's step length/leg length ratio was lower than TD children. The left-leg single-leg support time and step length of ID children were shorter than TD children. While walking, ID children touched the ground with the whole foot pad and could not powerfully thrust against the ground with their toes. Their left legs had obvious disadvantages compared with their right legs. ID children's lower limb muscle strength was lower than TD children, and their thigh muscles had an obvious compensation function.

CONCLUSIONS

Correcting ID children's gait should be an important teaching goal for physical education institutors and teachers. Muscle-strength and flexibility training can help ID children reinforce core strength and better coordinate lower limbs.

Comparison of forward and backward gait in males with and without intellectual disabilities

BACKGROUND

Intellectual disabilities (ID) affect both cognitive and motor functions. The backward gait is a daily activity and its assessment is used for fall risk estimation and training in the general population. For proper use of backward gait as a rehabilitation tool and in fall prevention programmes for people with ID, it is necessary to determine the backward gait characteristics in the ID population. The aim of this study was to compare the differences between forward and backward gait in persons with nonsyndromic mild and moderate ID, persons with Down syndrome (DS) and a control group of healthy adults.

METHODS

Fifty males divided into four groups (mild ID: n = 15, moderate ID: n = 19, DS: n = 6, controls: n = 10) participated in this study. All participants were asked to walk both forward and backward, barefooted and at their natural velocity on a Zebris FDM platform. The Kruskal-Wallis H test was used to compare differences between the analysed groups in forward and backward gait. The Mann-Whitney U test was used to compare the differences between forward and backward gait within each group.

RESULTS

The velocity was significantly slower in moderate ID and DS compared to controls in forward and backward gait. When comparing forward and backward gait within each group, the gait velocity decreased in backward gait compared with forward gait by 21.80% in controls, by 33.89% in mild ID, by 34.45% in moderate ID, and by 40.32% in DS. In both moderate ID and DS, the mean backward velocity was slower than 2.16 km/h, the velocity used to identify elderly fallers in the general population.

CONCLUSIONS

Gait velocity was especially affected in DS and moderate ID compared with controls. In both mentioned groups, the backward gait velocity suggests an increased risk of falling. Future studies are necessary to examine the possibility of improving balance control and leg muscle strength by backward walking training in the ID population.

Feasibility and Reliability Assessment of Video-Based Motion Analysis and Surface Electromyography in Children with Fragile X during Gait

Fragile X Syndrome (FXS), the leading form of inherited intellectual disability and autism, is characterized by specific musculoskeletal conditions. We hypothesized that gait analysis in FXS could be relevant for the evaluation of motor control of gait, and help the understanding of a possible correlation between functional and intellectual abilities. Typical deficits in executive control and hyperactivity have hampered the use of standard gait analysis. The aim of our study was to quantitatively assess musculoskeletal alterations in FXS children in standard ambulatory conditions, in a friendly environment. Ten FXS children and sixteen controls, with typical neurodevelopment, were evaluated through four synchronized video cameras and surface electromyography; lower limb joints rotations, spatiotemporal parameters, duration of muscle contraction, activation timing and envelope peaks were determined. Reliability and repeatability of the video based kinematics analysis was assessed with respect to stereophotogrammetry. The Kruskal–Wallis Test (p < 0.05) or SPM1D were used to compare different groups of subjects. Results show a consistently altered gait pattern associated with abnormal muscle activity in FXS subjects: reduced knee and excessive hip and ankle flexion, and altered duration and activity onset on all the recorded muscles (Rectus/Biceps Femoris, Tibialis Anterior, Gastrocnemius Lateralis). Results of this study could help with planning personalized rehabilitations.

The association between medication use and gait in adults with intellectual disabilities

BACKGROUND

Adults with intellectual disabilities (ID) often have polypharmacy and often use antipsychotics. Both polypharmacy and antipsychotics have a negative effect on gait in the general population, but this has not been studied in adults with ID. These negative effects may add to pre-existing gait disturbances in adults with ID and increase the risk for adverse health outcomes in this population. Therefore, the aim of this study is to investigate the difference in gait parameters between adults with ID with and without polypharmacy and between adults with ID using and not using antipsychotics.

METHOD

The gait parameters of 31 participants were collected with the GAITRite walkway, a pressure sensitive walkway measuring spatial and temporal gait parameters, in addition to information about personal characteristics, prescribed medication and presence of polypharmacy.

RESULTS

After adjustment for sex and body mass index, participants with polypharmacy had a significantly shorter step length [polypharmacy B (SE) = -0.079 (0.034), P = 0.03], shorter stride length [polypharmacy B (SE) = -0.157 (0.069), P = 0.03] and longer double support time [polypharmacy B (SE) = 0.0004 (0.0001), P = 0.047]. Participants using antipsychotics had a significantly longer double support time [antipsychotic use B (SE) = 0.0003 (0.0002), P = 0.019].

CONCLUSION

This study showed for the first time that both polypharmacy and using antipsychotics are associated with gait in adults with ID. The differences seem to resemble a more cautious gait. Further investigation with larger study samples, additional medication types and dosages are needed to acquire more insight in this important topic.

Development of a Smart Ball to Evaluate Locomotor Performance: Application in Adolescents with Intellectual Disabilities

Adolescents with intellectual disabilities display maladaptive behaviors in activities of daily living because of physical abnormalities or neurological disorders. These adolescents typically exhibit poor locomotor performance and low cognitive abilities in moving the body to perform tasks (e.g., throwing an object or catching an object) smoothly, quickly, and gracefully when compared with typically developing adolescents. Measuring movement time and distance alone does not provide a complete picture of the atypical performance. In this study, a smart ball with an inertial sensor embedded inside was proposed to measure the locomotor performance of adolescents with intellectual disabilities. Four ball games were designed for use with this smart ball: two lower limb games (dribbling along a straight line and a zigzag line) and two upper limb games (picking up a ball and throwing-and-catching). The results of 25 adolescents with intellectual disabilities (aged 18.36 ± 2.46 years) were compared with the results of 25 typically developing adolescents (aged 18.36 ± 0.49 years) in the four tests. Adolescents with intellectual disabilities exhibited considerable motor-performance differences from typically developing adolescents in terms of moving speed, hand–eye coordination, and object control in all tests.

Characteristic behaviors associated with gait of individuals with Rett syndrome

BACKGROUND

Individuals with Rett syndrome (RTT) exhibit impaired motor performance and gait performance, leading to decreased quality of life. Currently, there is no robust observational instrument to identify gait characteristics in RTT. Current scales are limited as individuals with intellectual disorders may be unable to understand instructions. Our primary purpose was to utilize video analysis to characterize the behaviors associated with walking in individuals with RTT and explore the relationship between behaviors during overground and during treadmill walking.

METHODS

Fourteen independently ambulatory females with RTT were video-taped and observed during overground and treadmill walking. Their gait was codified into an observational checklist to reveal prominent features associated with gait in this population.

RESULTS

Participants exhibited similar rates of freezing, veering, and hand stereotypies between overground and treadmill walking; however, freeze duration was shortened during treadmill walking. Toe walking was prominently exhibited during overground, but not treadmill walking. During both walking modes, participants required extensive external motivation to maintain their walking patterns.

CONCLUSIONS

Results identify several gait characteristics observable during overground and treadmill walking. In general, participants behaved similarly during overground and treadmill walking. We conclude that both overground and treadmill walking are appropriate tools to evaluate gait in this population.Implications for rehabilitationLocomotor rehabilitation may increase the quantity of walking performed by the patients, which can alleviate negative effects of the sedentary lifestyle commonly observed in patients with Rett syndrome (RTT).Video analysis of natural walking can be an effective tool to characterize gait in patients with RTT which does not require particular instructions which may not be fully understood.Both overground and treadmill walking are appropriate means of evaluating gait in individuals with RTT.

The Effect of Systematic Prompting on the Acquisition of Two Muscle-Strengthening Exercises by Adults with Moderate Disabilities

Musculoskeletal fitness is important for adults with intellectual disabilities (ID) to maintain cardiovascular fitness, functional independence, and work task performance, and to reduce the risk of chronic diseases and other disabilities. However, adults with ID typically have significantly lower musculoskeletal fitness compared with their peers without a disability. Appropriate instructional strategies are needed to facilitate their acquisition and maintenance of musculoskeletal fitness. In this study, three adults with moderate ID, aged 19-20 years, were selected to evaluate the effects of a multi-component treatment package that included a video-enhanced system of least-to-most prompts (LMP) on their acquisition of two muscle-strengthening machine exercises. Results from a multiple-baseline-across-participants single-subject design show substantive gains in correct and independent performance of steps in the two exercises during the treatment condition. The improved performance in both exercises was maintained one week and two weeks after the last treatment session and appeared to have extended to a large fitness room. The study suggests that use of the video-enhanced system of LMP as an additional or alternate type of instruction can lead to improved acquisition and maintenance of muscle-strengthening exercises by young adults with moderate ID.

Gait and postural control patterns and rehabilitation in Down syndrome: a systematic review

[Purpose] To describe (1) the current knowledge on gait and postural control in individuals with Down syndrome in terms of spatiotemporal, kinematics and kinetics, and (2) relevant rehabilitation strategies. [Methods] Randomized and non-randomized clinical trials published between January 1997 and October 2019 were selected by searching four scientific databases. We included studies on patients with Down syndrome involving gait analysis or postural control. A custom data-extraction and appraisal form was developed to collect the key features of each article. The PEDro Scale was used to evaluate the methodological quality of the studies. [Results] A total of 37 out of 146 cross-sectional and longitudinal studies were included in the review. The main abnormalities included: reduction of gait velocity and step length, poor static balance with increased anteroposterior and mediolateral oscillations and a larger step width. [Conclusion] A number of compensatory patterns during movement was observed, with a direct influence on improvements in stability and postural control throughout daily life. Intensive gait training at an early age appears to produce long-term improvements in this population. Future research should focus on the interaction between the motor and cognitive function, and on the functional effects due to the exposure to an enriched environment.

Feasibility and reliability of a physical fitness tests battery for adults with intellectual disabilities: The SAMU DIS-FIT battery

BACKGROUND

People with intellectual disability (ID) have lower performances in physical fitness (PF) tests than people without ID, a situation that exists during all the life stages. However, the assessment of the FP of persons with ID often uses instruments that were designed for non-disabled people.

AIM

To check the reliability and feasibility of 8 PF tests in adults with mild to moderate ID.

METHODS

A cross-sectional study was carried out with a test-retest design in a maximum interval of 2 weeks with 240 adults (160 men and 80 women) with mild to moderate ID in order to assess the feasibility and reliability of the following 8 tests: body mass index (BMI), waist circumference (WC), the timed up & go test (TUG), the deep trunk flexion test (DTF), the hand grip test (HG), the timed stand test (TST), the 30-s sit-up (SUP) test, and the 6-min walk test (6MWT). The complete battery was called the SAMU-Disability Fitness Battery (SAMU-DISFIT). The psychometric properties of the battery, feasibility, reliability, the standard error of the measurement (SEM) and the minimal detectable change (MDC) were calculated.

RESULTS

The TUG, DTF, HG, TST, and 6MWT showed an intraclass correlation coefficient (ICC) from fair to high reliability. Only the SUP test in men had an ICC lower than 0.7 and high SEM values.

CONCLUSION

The psychometric properties provide robust data on the use of the SAMU-DISFIT battery in people with ID and can be considered a useful tool for assessing PF in adults with mild to moderate ID in future research.

The Effect of Systematic Prompting on the Acquisition of Five Muscle-Strengthening Exercises by Adults With Mild Intellectual Disabilities

Adults with intellectual disability have significantly lower musculoskeletal fitness than their peers without a disability. Appropriate instructional strategies are needed to facilitate their acquisition and maintenance of musculoskeletal fitness. In this multiple-baseline across-participants single-subject study, the authors evaluated the effects of a multicomponent package that included a video-enhanced system of least-to-most prompts on the acquisition of 5 muscle-strengthening exercises in 3 women with mild intellectual disability, age 24-37 yr. Results show substantive gains in correct and independent performance of steps in the 5 exercises during the treatment condition. The improved performance was maintained 2 wk after the last treatment session and in a large YMCA gym. The study suggests that use of the video-enhanced system of least-to-most prompts can lead to improved acquisition and maintenance of muscle-strengthening exercises by adults with mild intellectual disability.

Assessment of patient clinical descriptions and pathogenic variants from gene panel sequences in the CAGI-5 intellectual disability challenge

The Critical Assessment of Genome Interpretation-5 intellectual disability challenge asked to use computational methods to predict patient clinical phenotypes and the causal variant(s) based on an analysis of their gene panel sequence data. Sequence data for 74 genes associated with intellectual disability (ID) and/or autism spectrum disorders (ASD) from a cohort of 150 patients with a range of neurodevelopmental manifestations (i.e. ID, autism, epilepsy, microcephaly, macrocephaly, hypotonia, ataxia) have been made available for this challenge. For each patient, predictors had to report the causative variants and which of the seven phenotypes were present. Since neurodevelopmental disorders are characterized by strong comorbidity, tested individuals often present more than one pathological condition. Considering the overall clinical manifestation of each patient, the correct phenotype has been predicted by at least one group for 93 individuals (62%). ID and ASD were the best predicted among the seven phenotypic traits. Also, causative or potentially pathogenic variants were predicted correctly by at least one group. However, the prediction of the correct causative variant seems to be insufficient to predict the correct phenotype. In some cases, the correct prediction has been supported by rare or common variants in genes different from the causative one.

Characterization of intellectual disability and autism comorbidity through gene panel sequencing

Intellectual disability (ID) and autism spectrum disorder (ASD) are clinically and genetically heterogeneous diseases. Recent whole exome sequencing studies indicated that genes associated with different neurological diseases are shared across disorders and converge on common functional pathways. Using the Ion Torrent platform, we developed a low-cost next-generation sequencing gene panel that has been transferred into clinical practice, replacing single disease-gene analyses for the early diagnosis of individuals with ID/ASD. The gene panel was designed using an innovative in silico approach based on disease networks and mining data from public resources to score disease-gene associations. We analyzed 150 unrelated individuals with ID and/or ASD and a confident diagnosis has been reached in 26 cases (17%). Likely pathogenic mutations have been identified in another 15 patients, reaching a total diagnostic yield of 27%. Our data also support the pathogenic role of genes recently proposed to be involved in ASD. Although many of the identified variants need further investigation to be considered disease-causing, our results indicate the efficiency of the targeted gene panel on the identification of novel and rare variants in patients with ID and ASD.

Down Syndrome: Gait Pattern Alterations in Posture Space Kinematics

Gait characteristics in Down syndrome (DS) are documented in terms of discrete kinematic variables. However, such features are strictly interrelated and reflect neurological and developmental delays. A phenotypical, quantitative assessment of how multi-joint walking patterns are activated and controlled during gait would enhance the understanding of locomotor mechanisms in such patients. We adopted an analysis framework based on principal component analysis: the gait kinematics of 221 patients aged 6-45 were expressed in terms of a reduced set of one-dimensional movement components. Their time course during the gait cycle was described by score vectors, here called principal positions; its second time derivative, called principal acceleration, characterized the activity of the neuromuscular controller on each component. Outcomes were compared to an age-matched group of 49 healthy individuals. After controlling for the effect of walking speed, we observed that the main alterations in gait patterns emerged in the fourth component which is mostly devoted to stability management (group differences, p < 0.001). Rather, the main sagittal-plane locomotor patterns showed only subtle differences from the control group. Using statistical parametrical mapping, we found when (step-to-step transitions) and how (interrelated joints motion) the fourth movement deviated from normal: in particular, an excessive hip adduction and trunk inclination during the transition between single and double support phases. These findings match the neurological and sensorimotor trait of DS and suggest the promotion of targeted rehabilitative interventions. Furthermore, this paper opens to the adoption of principal positions and principal accelerations to investigate the neuromuscular control of movement patterns during locomotion.

Feasibility and acceptability of Otago Exercise Programme and Prevention of Falls for Adults with Intellectual Disability: a multiple case study design

Background/Aims

Many people with intellectual disability fall frequently. Understanding fall prevention intervention characteristics will assist efficacy trials to target appropriate people. An exploration of two exercise-based fall prevention interventions is reported, focusing on viability and acceptability.

Methods

A multiple case study of adults with intellectual disability completing either the group Otago Exercise Programme or the Prevention of Falls for Adults with Intellectual Disability intervention was performed. Integrated data sources were used: semi-structured interviews with participants and support workers, observations, attendance/adherence, falls, adverse events and balance measures.

Results

In total, seven adults with varying intellectual disability levels participated. Overall, three themes enabled understanding of suitability of people to each intervention: suitability of the exercises; role of the environment; and benefits to participants.

Conclusions

Educating adults with intellectual disability and their support workers of the importance of regular exercise is key to participation. Both programmes required high levels of support and prioritisation to ensure exercises occurred and were carried out safely.

Clinical usefulness and challenges of instrumented motion analysis in patients with intellectual disabilities

BACKGROUND

Clinical laboratory testing of locomotor disorders is challenging in patients with intellectual disability (ID). Nevertheless, also in this population gait analysis has substantial value as motor problems are common. To promote its use, adequate protocols need to be developed and the impact on clinical decision making needs to be documented.

RESEARCH QUESTION

What is the clinical usefulness of instrumented motion analysis in patients with ID?

METHOD

This narrative review consists of three parts. A literature review was performed to describe the gait pattern of patients with ID. Next, benefits and challenges of standard gait analysis protocols are described. Finally, a case of a girl with ID due to genetic cause showing gait abnormalities is discussed.

RESULTS

The literature review resulted in 20 studies on "gait" in patients with an "ID", published since August, 1^st 2013. Gait deviations were observed in all studies investigating the ID population with an underlying genetic syndrome. Observed gait deviations in the ID population might be attributed to physical characteristics, cognitive components or both. The main goal of clinical gait assessment is the identification of gait deviations and the evaluation of their progress over time, in order to optimize the treatment plan. The choice of adequate method and measurement modalities depends on the clinical goal, the available resources and the abilities of the patient. In the case report we presented, we succeeded in performing an instrumented 3D gait analysis in a girl with severe ID at the ages of 4y4m, 6y0m, 7y2m and 8y2m. Progressive gait deviations were found suggesting a crouch gait pattern was developing. Results of the gait analysis led to the prescription of rigid ankle-foot orthoses.

SIGNIFICANCE

Gait analysis has substantial value for patients with ID. Gait analysis allows clinicians to objectify the relationship between physical characteristics and gait features.

Evaluation of podiatric disorders in a sample of children with intellectual disabilities: an analytical cross-sectional study

BACKGROUND

Intellectual disabilities (IDs) usually derive from neurodevelopmental disabilities. They limit intellectual functioning and cause adaptive behaviors and orthopedic problems. These disabilities have harmful effects on health, everyday practical skills and social functioning, and they diminish quality of life. The goal of our research was to perform podiatric evaluations on schoolchildren with and without ID and ascertain their records of foot disorders.

DESIGN AND SETTING

Analytical cross-sectional study conducted at a podiatric clinic in the city of Piedras Blancas, province of Asturias, Spain.

METHODS

An analytical cross-sectional study on 82 schoolchildren affected by ID, compared with 117 healthy schoolchildren, was conducted at a podiatric clinic. Demographic data, clinical characteristics and measurements relating to podiatric examinations were recorded among the participants who completed all phases of the tool that was used in the study process.

RESULTS

Almost 90% of the schoolchildren with and without ID presented foot disorders relating to smaller toes, nail disorders, flat feet or lower-limb alterations.

CONCLUSIONS

The participants showed elevated prevalence of foot disorders. Podiatric evaluations are a significant means for preventing the appearance of medical conditions and/or foot problems, and they also improve general health.

Physical activity levels of children and adolescents with moderate-to-severe intellectual disability

Background

Regular participation of children and adolescents with intellectual disabilites in physical activity is important to maintain good health and to acquire motor skills. The aim of this study was to investigate the habitual physical activity in these children.

Methods

Sixty‐eight children and adolescents (2–18 years) with a moderate‐to‐severe intellectual disability were included in the analyses. They wore an accelerometer on eight consecutive days. Data was analysed by use of descriptive statistics and multiple linear regression analyses.

Results

The participants took on average 6,677 ± 2,600 steps per day, with intensity of 1,040 ± 431 counts per minute. In total, 47% of the participants were meeting physical activity recommendations. Low motor development was associated with low physical activity.

Conclusions

As more than half of the participants were not meeting the recommendations, family and caregivers of these children should focus on supporting and motivating them to explore and expand their physical activities.

Gait Characteristics of Adults With Intellectual Disability

Gait is a relevant and complex aspect of motor functioning. Disturbances are related to negative health outcomes. Gait characteristics of 31 adults with intellectual disability (ID) without Down syndrome (DS) (42.77±16.70 years) were investigated, and associations with age, sex, body mass index (BMI), and level of ID were assessed. Sex and BMI were significantly associated with some of the gait parameters, while age and level of ID were not. Gait characteristics of adults with ID seem to be comparable to those of the general population of older adults (average 20 years older), except that adults with ID seem to spend less time in stance and double support phase and walk more variable and with a broader base of support.

The association between gait and physical fitness in adults with intellectual disabilities

BACKGROUND

Gait deviations are often seen in adults with intellectual disabilities (ID). Their low physical fitness levels may be associated with these deviations. Understanding the impact of fitness on gait in this population is important for developing interventions to improve gait. In a cross-sectional study, we assessed the association between multiple physical fitness components and spatiotemporal gait parameters in adults with ID.

METHOD

Gait characteristics of 31 adults (42.77 ± 16.70 years) with ID without Down syndrome were assessed with the GAITRite at comfortable (CS) and fast speed (FS), along with fitness assessments (body composition, muscular endurance, strength, balance, Short Physical Performance Battery).

RESULTS

At CS, adults with ID with higher BMI and/or waist circumference spent more time in double support. At FS, those with better muscular endurance took steps faster, those with better balance took bigger steps and strides and those with better Short Physical Performance Battery scores took bigger steps and strides at higher velocity.

CONCLUSIONS

Body composition was mostly associated with gait at CS, while the other physical fitness components were mostly associated with gait at FS. Better fitness may therefore be more important in more challenging conditions. These insights are useful for developing interventions to improve gait in adults with ID.

The dual task effect on gait in adults with intellectual disabilities: is it predictive for falls?

PURPOSE

Falling is an important health issue in adults with intellectual disabilities. Their cognitive and motor limitations may result in difficulties with dual tasking (walking and talking), which increases fall risk. Therefore, we assessed the dual task effect on gait in adults with intellectual disabilities, if this dual task effect is predictive for falls, and if this is more predictive than regular walking.

METHOD

Gait characteristics of 31 adults with intellectual disabilities without Down syndrome were assessed with the GAITRite at comfortable speed and during dual tasking (conversation). Falls were collected over a three-month follow-up period.

RESULTS

During dual tasking, participants walked slower, with a lower cadence, increased stride time, and shorter stride lengths. They spend less time in swing and single support phase than at comfortable speed. Also swing and single support time became more variable. The dual task effect and walking at comfortable speed were not predictive for falls, although medium effect sizes were found.

CONCLUSIONS

Dual tasking affects gait in adults with intellectual disabilities. This is an important finding for safe community participation, and must be considered while interacting with adults with intellectual disabilities during daily activities. Possible negative consequences of distractors should be kept in mind. More research is needed to better understand the predictive value of gait for falls. Implications for Rehabilitation Having a conversation while walking affects the gait pattern of adults with intellectual disabilities, possible negative consequences of distractors should be kept in mind. The dual task effect on the width of the gait pattern and stride time variability had the largest effect sizes with future falls, this potential relationship should be kept in mind in clinical practice. The dual task effect on gait is important to consider with regard to safe community participation. Future studies are needed to better understand the predictive value of gait for falls, and for cutoff points to be used in clinical practice.

Stair-Walking Performance in Adolescents with Intellectual Disabilities

Most individuals with intellectual disabilities (ID) demonstrate problems in learning and movement coordination. Consequently, they usually have difficulties in activities such as standing, walking, and stair climbing. To monitor the physical impairments of these children, regular gross motor evaluation is crucial. Straight-line level walking is the most frequently used test of their mobility. However, numerous studies have found that unless the children have multiple disabilities, no significant differences can be found between the children with ID and typically-developed children in this test. Stair climbing presents more challenges than level walking because it is associated with numerous physical factors, including lower extremity strength, cardiopulmonary endurance, vision, balance, and fear of falling. Limited ability in those factors is one of the most vital markers for children with ID. In this paper, we propose a sensor-based approach for measuring stair-walking performance, both upstairs and downstairs, for adolescents with ID. Particularly, we address the problem of sensor calibration to ensure measurement accuracy. In total, 62 participants aged 15 to 21 years, namely 32 typically-developed (TD) adolescents, 20 adolescents with ID, and 10 adolescents with multiple disabilities (MD), participated. The experimental results showed that stair-walking is more sensitive than straight-line level walking in capturing gait characteristics for adolescents with ID.

Autism Spectrum Disorder, Intellectual Disability, and Delayed Walking

OBJECTIVE

Delayed onset of independent walking is common in intellectual disability (ID). However, in children with autism spectrum disorders (ASD), delayed walking has not been reported as frequently, despite the high rate of concurrent ID in ASD. This study directly examined the relationship between delayed walking and severity of ID in children with ASD versus other non-ASD diagnoses.

METHOD

Participants were 1185 individuals (ASD, n = 903; non-ASD, n = 282) who received an assessment at age 4 to 12 years (6.89 ± 2.25) that yielded an estimate of nonverbal IQ (NVIQ) and retrospectively reported age of walking from the Autism Diagnostic Interview-Revised. The relationship between diagnostic group and delayed walking (defined as occurring at ≥16 months) as a function of NVIQ was explored using the Cox proportional hazards model.

RESULTS

Children with ASD were less likely to exhibit delayed walking than those with non-ASD diagnoses, and this difference was larger at lower levels of NVIQ (P = .002). For example, rates of delayed walking for ASD and non-ASD were 13% and 19%, respectively, in those with NVIQ >85 but 31% and 60% in children with NVIQ <70.

CONCLUSIONS

Although lower IQ scores were associated with increased rates of late walking in both ASD and non-ASD groups, children with low IQ were more likely to show delayed walking in the absence of ASD. This raises the possibility of separate etiological pathways to ID in children with and without ASD.