Reliability of center of pressure excursion as a measure of postural control in bipedal stance of individuals with intellectual disability: A pilot study

The effects of sleep deprivation on the balance system: following normal sleep, 24 h of sleep deprivation, and rest under eyes-open and eyes-closed conditions

OBJECTIVE

This study investigated the effects of sleep deprivation (SD) on balance after normal sleep, 24 h of SD, and subsequent rest under eyes-open (EO) and eyes-closed (EC) conditions. Our aim was to ascertain whether the reduced efficiency of balance control following SD is generalized or selective.

METHOD

Nineteen participants (12 females, 7 males) completed the Pittsburgh Sleep Quality Index (PSQI). The mean ages for male participants were 24.14 ± 0.37 years, their height was 180.71 ± 5.46 cm, and weight of male participants were 81.71 ± 13.42 kg. For female participants, the mean ages were 24.41 ± 4.01 years, their height was 163.66 ± 2.64 cm, and their weight was 59.54 ± 9.18 kg. Stance analyses were conducted after normal sleep, 24 h of SD, and subsequent rest of both the EO and EC. Participants performed a normal balance test, a second test while holding cubes and counting backwards from 200 by sevens, and a third test after rest under EO and EC.

RESULTS

Independent samples t-tests showed significant height and weight differences between sexes (p < 0.05), with females generally smaller. No significant differences were found in age, daytime sleep duration, or PSQI score (p > 0.05). Significant differences in parameters such as length of the minor axis (lomna), angle, and area were observed in EO and EC across the three days, revealing the interplay between visual stimuli, cognitive tasks, and parameter stability.

CONCLUSION

SD has multifaceted impacts on motor and cognitive performance, even when attentional and sensory resources are not strained. Our findings elucidate the nuanced impact of SD on cognitive performance, and suggest the efficacy of external factors in mitigating its effects on postural control.

Do Motor-Cognitive and Motor-Motor Dual-Task Training Differently Affect Dual-Task Interference in Individuals With Intellectual Disability?

This study explored the effect of different dual-task (DT) training programs on DT interference in adults with intellectual disability. Center-of-pressure (CoP) mean velocity in single-task (ST) and cognitive-DT conditions and the Timed Up-and-Go Test (TUGT) during ST, cognitive-DT, and motor-DT conditions were assessed before and after intervention in a cognitive-motor training group, a motor-motor training group, and a control group. Before training, CoP mean velocity and TUGT time increased (p < .001) in DT compared with the ST condition. After training, the CoP mean velocity values remained unchanged (p = .07) in DT compared with the ST condition among the cognitive-motor training group. Furthermore, compared with the ST condition, no increase (p = 1) was reported in the TUGT time during the cognitive-DT condition for the cognitive-motor training group and during the motor-DT for the motor-motor training group (p = .12). The effect of DT training on DT interference depends on the training modality.

Reliability of Obstacle-Crossing Parameters during Overground Walking in Young Adults

We aimed to evaluate the intra-session relative and absolute reliability of obstacle-crossing parameters during overground walking in young adults, and to determine the number of trials required to ensure reliable assessment. We analysed data from 43 young male adults who were instructed to walk at a self-selected velocity on a pathway and to step over an obstacle (height = 15 cm; width = 80 cm, thickness = 2 cm) three times. Spatial-temporal gait parameters of the approaching and crossing phases (i.e., before and after the obstacle) and obstacle clearance parameters (i.e., vertical and horizontal distance between the foot and the obstacle during crossing) were computed using a three-dimensional motion analysis system. Intraclass correlation coefficients were used to compute the relative reliability, while standard error of measurement and minimal detectable change were used to assess the absolute reliability for all possible combinations between trials. Results showed that most spatial-temporal gait parameters and obstacle clearance parameters are reliable using the average of three trials. However, the mean of the second and third trials ensures the best relative and absolute reliabilities of most obstacle-crossing parameters. Further works are needed to generalize these results in more realistic conditions and in other populations.

Analysis of the centre of pressure in bipedal stance among individuals with and without intellectual disabilities, individuals with Down syndrome and dancers with Down syndrome

BACKGROUND

Individuals with intellectual disabilities (IDs) often present deficiencies in motor, balance and postural control. On the other hand, the practice of physical activity and dance usually reduces these deficiencies. Therefore, in this study, we aimed to compare the control of the centre of pressure (COP) in people with Down syndrome (DS) or other causes of ID in relation to people without disabilities and to observe the influence of vision and the practice of dance.

METHODS

This cross-sectional study analyses the COP in a static standing position with open and closed eyes in four study groups. A total of 273 people were recruited (80 adults without ID, 46 adults with DS, 120 adults with other causes of ID and 27 dancers with DS).

RESULTS

A greater area of oscillation and path of the COP was observed in the participants with ID compared with the participants without ID, especially in the sway area of the COP. The oscillation speed of the COP was also higher. When analysing the displacement of the COP, anteroposterior and mediolateral components, there were also differences, except when comparing the group of dancers with DS with respect to the group without ID. The visual condition only influenced the group of participants without disabilities.

CONCLUSIONS

The results of our study show that there is a less efficient static postural control in people with ID, as greater displacements were observed in the COP of the participants with ID. The differences in some specific variables that analyse the displacement of the COP were smaller when comparing the group of dancers with DS and the individuals without ID.

Cognitive-motor interference during standing stance across different postural and cognitive tasks in individuals with Down syndrome

BACKGROUND

Individuals with Down syndrome (DS) presented both cognitive and motor impairments that could influence each other. Therefore, exploring cognitive-motor interference during standing stance is relevant in this population.

AIMS

This study explored the dual task (DT) effects on postural balance during diverse cognitive tasks and sensory manipulations in individuals with DS, compared to those with typical development (TD).

METHODS AND PROCEDURES

Fifteen adolescents with DS (age = 14.26 ± 1.27 years; height = 1.50 ± 0.02; weight = 46.46 ± 4.03 kg; BMI =20.54 ± 1.51 kg/m²) and thirteen with TD (age = 14.07 ± 1.11 years; height = 1.50 ± 0.05; weight = 44.92 ± 4.15 kg; BMI =19.77 ± 0.94 kg/m²) participated in this study. Postural and cognitive performances for the selective span task (SST) and the verbal fluency (VF) were recorded during single task (ST) and DT conditions. Postural conditions were: firm eyes open (firm-EO), firm eyes closed (firm-EC) and foam-EO. Motor and cognitive DT costs (DTC) were calculated and analyzed across these different cognitive and postural conditions.

OUTCOMES AND RESULTS

In the DS group, postural performance was significantly (p < 0.001) altered during all DT conditions, compared to the ST situation. Moreover, the motor DTC was significantly (p < 0.001) higher while performing the VF task than the SST. However, in the control group, postural performance was significantly (p < 0.001) impaired only while performing the VF test in the DT-Firm EO condition. For both groups, cognitive performances were significantly (p < 0.05) altered in all DT conditions compared to the ST one.

CONCLUSION

Adolescents with DS are more prone to DT effects on postural balance than those with TD.

Comparing body posture and postural control in children with intellectual disability and dyslexia to typically developing children using technology‑based assessments

Background/Aims

Children with intellectual disability and dyslexia have poor academic and behavioural skills related to social participation, as well as poor motor skills compared to typically developing children. Most training programmes for these children focus on the academic and behavioural aspects of special education, overlooking musculoskeletal and motor development needs. The aim of this study was to investigate body posture and postural control in children with intellectual disability and dyslexia compared to typically developing children using technology-based assessments.

Methods

A total of 77 children (36 with dyslexia, 21 with intellectual disability and 20 typically developing children) took part in the study. The PostureScreen Mobile app was used to evaluate body posture and the Fizyosoft Balance System was used to assess postural control.

Results

Significant postural differences were observed in children with intellectual disability when compared to typically developing children. Head, shoulder and knee translations in the sagittal plane were significantly higher in children with intellectual disability than typically developing children. Centre of pressure velocities were significantly higher in children with dyslexia. Centre of pressure displacements showed non-significant differences in the children with dyslexia compared to the children with intellectual disability and typically developing children.

Conclusions

The present study found that children with dyslexia had poor postural control and children with intellectual disability had poor quality of posture compared to typically developing children. The authors believe that motor and physical assessments with objective outcome measurements should be conducted for children with dyslexia and intellectual disability to help improve their motor development.

Athletes with intellectual disability: The effects of cognitive deficits and sports practice on bipedal standing balance

BACKGROUND

Athletes with intellectual disability represent a unique population who experiences the contrasting effects of cognitive deficits and benefits of sports on balance. This study investigated the combined impact of intellectual disability and sport practice on balance.

METHOD

Center-of-pressure excursion in bipedal stance of 2 disability (with and without intellectual disability) × 2 sport practice (athlete and novice) participant groups was measured in several balance conditions.

RESULTS

Sport practice exerted no significant effect on any of the center-of-pressure measures used. In contrast, intellectual disability's effects on balance, which were most apparent in challenging balance conditions, were significant (p < .05) and had large effect sizes (η_p ²  > 0.13).

CONCLUSION

The negative effects of cognitive deficits on the balance of young adults with intellectual disability underscore the need for effective interventions. Although findings did not support sports' balance-remediating potential, the value of sport participation for individuals with intellectual disability cannot be fully dismissed just yet.

Application of a virtual reality tracker-based system to measure seated postural stability in stroke patients

Background

Postural stability while sitting is an important indicator of balance and an early predictor for future functional improvement in neurorehabilitation, but the evaluation is usually dependent on clinical balance function measures. Meanwhile, instrumental posturography has been used widely to obtain quantitative data and characterize balance abilities and underlying control mechanisms, but not as often for sitting balance. Moreover, traditional kinetic methods using a force platform to test sitting stability often require modification and are costly. We proposed a tracker-based posturography with a commercial virtual reality system, the VIVE Pro system (HTC, Inc. Taiwan), to record the trunk displacement (TD) path with a lumbar tracker for evaluation of sitting stability. The goals were to test the reliability and validity of the TD parameters among stroke patients.

Methods

Twenty-one stroke individuals and 21 healthy adults had their postural sway measured with this system under four sitting conditions, i.e., sitting on a solid surface or a soft surface, with eyes open or closed. The test–retest reliability of the TD parameters was evaluated with intraclass correlation coefficients in 22 participants. We also tested the discriminative validity of these parameters to discriminate between stroke and healthy controls, and among four sitting conditions. Furthermore, the TD parameters were correlated with the three balance function tests: the Berg Balance Scale (BBS), the Postural Assessment Scale for Stroke Patients (PASS) and the Function in Sitting Test (FIST).

Results

The results indicated that the TD parameters obtained by tracker-based posturography had mostly moderate to good reliability across the four conditions, with a few exceptions in the solid surface and eyes open tasks. The TD parameters could discriminate the postural stability between sitting on solid and soft surfaces. The stroke group had more seated postural sway than the control group, especially while sitting on a soft surface. In addition, velocity measures in the sagittal and frontal planes had moderate to high correlations with the PASS and BBS scores.

Conclusions

This tracker-based system is a cost-effective option for the clinical assessment of body stability for stroke patients in a seated position and shows acceptable reliability and validity.

Balance Evaluation and Gait Analysis After Arthroscopic Partial Meniscectomy

Purpose

The purpose of this study is to investigate how walking and balance are affected at different time intervals after arthroscopic partial meniscectomy (APM).

Methods

Forty-five patients with APM and a healthy control group of 46 people were included in the study. Gait and bipedal balance analysis were performed to the patient group twice in 4 weeks and 12 weeks after surgery.

Results

In the gait analysis performed after 4 weeks, stance phase (SP), step time (ST), and total double support (TDS) were higher, and step length (SL), swing phase (SWP), cadence (C), and speed (V) in the patient group were lower. After 12 weeks, SP, TDS, and step width (SW) data were higher in the patient group and SWP was lower. In both measurements, the gait of the patient group is not symmetrical. In open-eye balance test, it was observed that the data of length of ellipse (LoE), area of ellipse (AoE), and path length of CoP (PL) were different after 4 weeks but these differences disappeared after 12 weeks. Width of ellipse (WoE), LoE, AoE, and PL data were different in the test performed with eyes closed after 4 weeks. In addition to the same data after 12 weeks, the medio-lateral direction (ML) was also higher than the patient group.

Conclusion

After 12 weeks, walking has not fully recovered. There was no difference in the balance analysis with eyes open, but the differences were still present in the eyes-closed analysis.

Acoustic Environmental Conditions (Do Not?) Affect the Static Posturography Diagnostic Accuracy: A Test-Retest Reliability Study

Static posturography assessed with force platforms is a procedure used to obtain objective estimates related to postural adjustments. However, controlling multiple intrinsic and extrinsic factors influencing the diagnostic accuracy is essential to obtain reliable measurements and recommend its use with clinical or research purposes. We aimed to analyze how different environmental acoustic conditions affect the test−retest reliability and to analyze the most appropriate number of trials to calculate a valid mean average score. A diagnostic accuracy study was conducted enrolling 27 healthy volunteers. All procedures were taken considering consistent device settings, posture, feet position, recording time, and illumination of the room. Three trials were recorded in a silent environment (35−40 dB) and three trials were recorded in a noisy environment (85−90 dB). Results showed comparable reliability estimates for both acoustic conditions (ICC = 0.453−0.962 and 0.621−0.952), but silent conditions demonstrated better sensitivity to changes (MDC = 13.6−76%). Mean average calculations from 2 and 3 trials showed no statistically significant differences (p > 0.05). Cross-sectional studies can be conducted under noisy or silent conditions as no significantly different scores were obtained (p > 0.05) and ICC were comparable (except oscillation area). However, longitudinal studies should consider silent conditions as they demonstrated better sensitivity to real changes not derived from measurement errors.

Cognitive-motor multitasking in athletes with and without intellectual impairment

PURPOSE

We investigated cognitive-motor multitasking in 29 top athletes with intellectual impairment (II) recruited during the European Championship Games organized by Virtus (World Intellectual Impairment Sports) and 29 control (CT) athletes matched for age, sex, sports practiced, and lifetime accumulated practice hours.

METHODS

Participants performed a cognitive task that required recognizing previously displayed visual objects among distractors. The motor task required maintaining a stable upright posture balancing on a rocking board placed atop a force plate which assessed center-of-pressure (COP) movement. Both tasks were performed separately (with participants seated for the cognitive single task) and concurrently under dual-task conditions, wherein participants memorized objects while balancing. We analyzed recognition accuracy, COP path length, and sample entropy of the COP trajectory as a measure for automaticity of postural control.

RESULTS

As expected, CT-athletes outperformed II-athletes in the cognitive task but the two groups have comparable performance in the postural task under single- and dual-task conditions. When multitasking, CT-athletes switched to more automatic postural control and maintained their postural sway at single-task levels. II-athletes prioritized balance thereby successfully keeping COP excursion comparable to single-task conditions. However, this came with pronounced costs for memory performance, which was unaffected by multitasking in CT-athletes.

CONCLUSION

The adaptive capacity observed in control athletes was not at the disposal of II-athletes who revealed pronounced sensitivities to multitasking interference. This sensitivity obviously was not compensated for by either athletic competence or potential transfer of athletic skill to domain-general cognitive functions.