Unilateral Fatigue Affects the Unipedal Postural Balance in Individuals With Intellectual Disability

The influence of cognitive load and vision variability on postural balance in adolescents with intellectual disabilities

Introduction

This study aimed to investigate the impact of cognitive load, particularly its escalation during the execution of the same test, under varying vision conditions, on postural balance among adolescents with intellectual disability (ID).

Methods

Twenty adolescents underwent balance assessments under different visual conditions (Open Eyes (OE), Closed Eyes (CE), Flash, Goggles, Visual Stimulation (VS)) and task settings (Single Task (ST), Dual Task (DT) without challenges, and DT with challenges). The cognitive test was assessed using Verbal Fluency (VF).

Results and discussion

Significant effects were found for Task (p < 0.001, ηp2 = 0.85), indicating that CoP values significantly increased (p < 0.05) with the introduction of the DT. Dual Task Cost (DTC) demonstrated significant effects for Vision (p = 0.008, ηp2 = 0.62), with values varying significantly (p < 0.05) among different vision conditions, especially in CE and Flash conditions. Visual Dependency Quotient (VDQ) analyses revealed significant effects of condition (p < 0.001, ηp2 = 0.84), with significant changes observed in CE/OE and Flash/OE conditions (p < 0.05). Significant effects were observed for Cognitive performance in the Challenge condition (p < 0.001, ηp2 = 0.86), with decreased performance with cognitive task challenges, particularly in Flash and Goggles conditions (p < 0.05). In conclusion, cognitive tasks, especially challenging ones, and visual variations significantly impact postural balance in adolescents with ID.

Impact of neuromuscular training including balance, strength and plyometric exercises on static and dynamic balance in high-level male runners with mild intellectual disability

BACKGROUND

This study aims to investigate the impact of neuromuscular training (NMT) on static and dynamic postural balance (PB) among high-level male runners with intellectual disability.

METHOD

Twenty-seven runners were randomly assigned to a NMT group and a control group who maintained their conventional training. Static and dynamic PB were assessed using the centre of pressure (CoP) excursions (in bipedal and unipedal stances under open eyes (OE) and closed eyes (CE) conditions) and the star excursion balance test (SEBT), respectively, at pre-training and post-training.

RESULTS

The NMT group showed significantly (p < 0.05) decreased CoP values and increased SEBT scores at post-training compared to pre-training. The switch from OE to CE did not affect static PB in the bipedal stance, only in the NMT group.

CONCLUSIONS

The NMT was effective in improving static and dynamic PB in runners with intellectual disability. The NMT could reduce visual dependency.

Combined effect of gender differences and fatiguing task on postural balance, functional mobility and fall risk in adults with multiple sclerosis: A preliminary study

AIM

To investigate the gender difference effect on postural balance, functional mobility, and fall risk after performing a fatiguing task in adults with multiple sclerosis (MS).

METHODS

Eleven women (30.91 ± 8.19 years) and seven men (30.29 ± 7.99 years) with relapsing-remitting MS performed a fatiguing task: three sets of the Five-repetition Sit-To-Stand Test (5-STST) were performed before and after the six-minute WalkTest (6MWT). Bipedal postural balance in eyes open and eyes closed conditions were assessed prefatigue (T0) and postfatigue (T3) using a force platform. Unipedal balance, functional mobility (Timed Up and Go Test), fall risk (Four Square Step Test) and fatigue [Visual Analogue Scale of Fatigue (VASF)] were assessed at T0 and T3. Heart rate (HR) and Rating of Perceived Exertion (RPE) were recorded before (only for HR), during and after the fatiguing task.

RESULTS

Compared to women, men showed an impairment of posturographic parameters [mean center of pressure (CoP) velocity (CoPVm) in both conditions (p < 0.05); CoP sway area (CoPAr) in both conditions (p < 0.01)], unipedal balance on the dominant leg (p <0.001), mobility (p<0.001) and an increased fall risk (p < 0.05). No gender differences were observed in 6MWT, 5-STST, HR, RPE, and VASF.

CONCLUSION

This preliminary study showed that fatiguing task negatively affected postural control, mobility and fall risk only in men. These gender differences were inconclusive but could be taken into account in postural balance rehabilitation programs for MS persons.

The Disturbing Effect of Neuromuscular Fatigue on Postural Control Is Accentuated in the Premenstrual Phase in Female Athletes

This study explored the fatigue effect on postural control (PC) across menstrual cycle phases (MCPs) in female athletes. Isometric maximal voluntary contraction (IMVC), the center of pressure sway area (CoParea), CoP length in the medio-lateral (CoP_LX) and antero-posterior (CoP_LY) directions, and Y-balance test (YBT) were assessed before and after a fatiguing exercise during the follicular phase (FP), mid-luteal phase (LP), and premenstrual phase (PMP). Baseline normalized reach distances (NRDs) for the YBT were lower (p = 0.00) in the PMP compared to others MCPs, but the IMVC, CoParea, CoP_LX, and CoP_LY remained unchanged. After exercise, the IMVC and the NRD decrease was higher at PMP compared to FP (p = 0.00) and LP (p = 0.00). The CoParea, CoP_LX, and CoP_LY increase was higher in the PMP compared to FP (p = 0.00) and LP (p = 0.00). It was concluded that there is an accentuated PC impairment after exercise observed at PMP.

Static postural balance between male athletes with intellectual disabilities and their sedentary peers: A comparative study

BACKGROUND

Previous reports showed that athletes without disabilities have better postural skills than their sedentary peers. This finding has not been elucidated in athletes with intellectual disabilities despite their decreased postural balance. This study aims to investigate static postural balance in track and field athletes with intellectual disabilities compared to their sedentary peers.

METHODS

Eighteen track and field athletes with intellectual disabilities (23.5 ± 4.52 years) and 18 sedentary peers (20.3 ± 3.4 years) participated in this study. A stabilometric platform was used to assess static postural balance in bipedal and unipedal stances with open (OE) and closed (CE) eyes.

RESULTS

In OE, the result showed significantly better static postural balance (CoP_Vm : p < .001; CoP_area : p < .001) in athletes compared to the sedentary ones in both stances. In CE, this difference was not observed in the unipedal stance.

CONCLUSION

Track and field experience may improve static postural balance in athletes with intellectual disabilities, mainly when visual input is available.

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

The high prevalence of postural instability in individuals with intellectual disability (ID) warrants the need for reliable and practical postural control assessments. Stabilometry is a postural control assessment that has been widely used for clinical populations. However, the scant systematic knowledge about the reliability of stabilometric protocols for adults with ID renders results questionable and limits its value for clinicians and researchers. The study's purpose was to develop a stabilometric protocol for adults with and without ID based on optimal combinations of shortest necessary trial durations and the least number of trial repetitions that guarantee sufficient reliability. Participants performed six trials of bipedal standing in 2 vision (eyes open vs eyes closed) x 2 surface (solid vs compliant) conditions on a force platform. Several parameters were calculated from the first 10-, 20-, and 30-s interval of every center-of-pressure (COP) trial data. For different trial durations, we identified the number of trials that yielded acceptable relative (intraclass correlation coefficient ≥ 0.70) and absolute (standard error of measurement < 20%) reliability using the Spearman-Brown prophecy formula. To determine the optimal combination of trial duration and number of repetition for each COP parameter, we implemented a two-step process: 1) identify the largest number of repetition for each of the three trial durations and then 2) select the trial duration with the lowest number of repetition. For both ID- and non-ID groups, we observed a trend whereby shorter trial durations required more repetitions and vice versa. The phase plane and ellipse area were the most and least reliable center-of-pressure parameter, respectively. To achieve acceptable reliability, four 30-s trials of each experimental condition appeared to be optimal for testing participants with and without ID alike. The results of this research can inform stabilometric test protocols of future postural control studies of adults with ID.

Dynamic Balance in Athletes With Intellectual Disability: Effect of Dynamic Stretching and Plyometric Warm-Ups

CONTEXT

Athletes with intellectual disability (ID) have a high risk of injury while participating in various sports. Warm-up (WU) is the most preventive measure to reduce injuries in sports.

OBJECTIVE

To investigate the effects of dynamic stretching WU (DS-WU) and plyometric WU (PL-WU) on dynamic balance in athletes with ID.

DESIGN

Crossover study.

SETTING

Research laboratory.

PARTICIPANTS

A total of 12 athletes with ID (age 24.5 [3.22] y, height 165.7 [8.4] cm, weight 61.5 [7.1] kg, intelligence quotient 61.1 [3.5]).

MAIN OUTCOME MEASURES

Dynamic balance was assessed using the Star Excursion Balance Test (SEBT) at pre-WU, post-WU, and 15 minutes post-WU for both the DS-WU and the PL-WU. A 2-way analysis of variance (3 sessions × 2 WU methods) with repeated-measures was used in this study.

RESULTS

Following the DS-WU, participants demonstrated significant improvements in the SEBT composite score post-WU (89.12% [5.54%] vs 87.04% [5.35%]; P < .01) and at 15 minutes post-WU (89.55% [5.28%] vs 87.04%, P < .01) compared with pre-WU. However, no significant difference between these two post-WU scores (post-WU and 15 min post-WU) was found. For the PL-WU, participants demonstrated a significant decrease in the SEBT composite score at post-WU (85.95% [5.49%] vs 87.02% [5.73%]; P < .05); however, these scores increased significantly at 15 minutes post-WU (88.60% [5.42%] vs 87.02% [5.49%]; P < .05) compared with that at pre-WU. The SEBT composite scores are significantly higher in the DS-WU than in the PL-WU at both post-WU sessions (P < .05).

CONCLUSION

Both DS-WU and PL-WU could improve dynamic balance and may be recommended as WUs in athletes with ID; however, particular caution should be exercised immediately after the PL-WU.