Effect of head position and visual condition on balance control in inverted stance

Effectiveness of whole-body vibration in patients with cerebral palsy: A systematic review and meta-analysis

BACKGROUND

This study examined the effects of systemic vibration exercises on cerebral palsy patients.

METHODS

Literature published in Cumulated Index to Nursing and Allied Health Literature (CINAHL), Cochrane library, Embase, Physiotherapy Evidence Database (PEDro), and PubMed was reviewed. A total of 2978 studies were initially retrieved. After further reading of the full texts 17 articles were finally included. A quality assessment of the included studies was conducted using the risk of bias (RoB) 2.0, and the Funnel plot and the Egger test were conducted to confirm the publication bias. Subgroup analysis was carried out according to the dependent variables, the international classification of functioning, disability, and health (ICF), frequency, treatment period and age.

RESULTS

The overall effect size of homogeneity was 0.474 (CI = 0.148-0.801). The analysis of the dependent variables showed the following order of the effect size: balance, muscle strength, spasticity, bone density, range of motion of the joint, gait function, and motor function. In the ICF classification, the effect size was observed to follow the order of body structure and function, activity, and participation. The effect size in the intervention according to the treatment period showed the following order: 7 to 12 weeks, 1 to 6 weeks, and 14 to 24 weeks. The age-dependent classification showed the following order in the effect size: school age, adolescent and adult, and infant and school age.

CONCLUSIONS

Systemic vibration is the most effective intervention to improve the balance and gait in patients with cerebral palsy and improve the body structure and function according to the ICF.

Balance control during stance - A comparison between horseback riding athletes and non-athletes

Horseback riding requires the ability to adapt to changes in balance conditions, to maintain equilibrium on the horse and to prevent falls. Postural adaptation involves specific sensorimotor processes integrating visual information and somesthesic information. The objective of this study was to examine this multisensorial integration on postural control, especially the use of visual and plantar information in static (stable) and dynamic (unstable) postures, among a group of expert horse rider women (n = 10) and a group of non-athlete women (n = 12). Postural control was evaluated through the center of pressure measured with a force platform on stable and unstable supports, with the eyes open and the eyes closed, and with the presence of foam on the support or not. Results showed that expert horse rider women had a better postural stability with unstable support in the mediolateral axis compared to non-athletes. Moreover, on the anteroposterior axis, expert horse riders were less visual dependent and more stable in the presence of foam. Results suggested that horseback riding could help developing particular proprioceptive abilities on standing posture as well as better postural muscle tone during particular bipodal dynamic perturbations. These outcomes provide new insights into horseback riding assets and methodological clues to assess the impact of sport practice.

BIOMECHANICAL CHARACTERISTICS IN YOGA SIRSASANA

The aim of this study was to understand how to process Yoga headstand and the difference between genders in headstand. Twelve skilled participates were recruited in this study (Males 34.1 [Formula: see text] 3.3 years, [Formula: see text]; Females 36.5 [Formula: see text] 3.9 years, [Formula: see text]). The 10 camera Vicon motion capture system, Kistler force plate, and Medilogic pressure mat were used synchronously to record the movement, ground reaction force, and pressure distribution during headstand. The Mann–Whitney U test and Friedman test ([Formula: see text]) was applied to assess the statistics. The trunk, hip, knee, and ankle joint angles were [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], respectively, in all subjects. The pressure distribution was 38 [Formula: see text] 19%, 29 [Formula: see text] 12%, and 33 [Formula: see text] 9% on subjects’ heads, right elbows, and left elbows, respectively. The COP trajectory was 31.2 [Formula: see text] 17.4[Formula: see text]cm and surface area was 5.3 [Formula: see text] 1.4[Formula: see text]cm2. No significant differences were found in joint angles, overall force distribution, and COP trajectory and surface area between genders. Both males and females distribute body weight to the supports of head and elbows equally and kept the body straight and erect on the ground during Yoga headstand.

The effect of close proximity holographic wristbands on human balance and limits of stability: a randomised, placebo-controlled trial

The purpose of this study was to investigate the effect of holographic technology wristbands on human balance and stability performance. Forty-two individuals volunteered to participate in the study. A performance technology silicone wristband containing two holograms was utilised as the 'Device'. A 'placebo' performance technology silicone wristband was utilised where the two holograms were removed and replaced with two stainless steel discs to the same dimensions and weight as the Device. Each participant was randomly allocated into two different testing protocol groups: Protocol 1 (Device-baseline-placebo) and Protocol 2 (placebo-baseline-Device). One week following the initial testing, the Protocol 1 group was tested under the conditions of Protocol 2, and vice versa, so that all participants were taken through both protocols. Results indicated that there was no statistically significant mean change in balance performance brought about by either the placebo or the Device. Notably, the sample data indicated an overall decrease in balance and stability. However, these mean changes are still within the bounds of what would be expected assuming the Device had no overall effect. The findings of this study indicate that holographic technology wristbands have no effect on human balance and stability performance.

Influence of pathologic and simulated visual dysfunctions on the postural system

Visual control has an influence on postural stability. Whilst vestibular, somatosensoric and cerebellar changes have already been frequency analytically parameterized with posturography, sufficient data regarding the visual system are still missing. The aim of this study was to evaluate the influence of pathologic and simulated visual dysfunctions on the postural system by calculating the frequency analytic representation of the visual system throughout the frequency range F1 (0.03-0.1 Hz) of Fourier analysis. The study was divided into two parts. In the first part, visually handicapped subjects and subjects with normal vision were investigated with posturography regarding postural stability (stability effect, Fourier spectrum of postural sway, etc.) with open and closed eyes. The visually impaired and the normal group differed significantly in the frequency range F1 (p = 0.002). Significant differences of the postural stability between both groups were found only in the test position with open eyes (NO). The healthy group showed a significant loss of stability, whereas the impaired group showed an increased stability due to sufficient somatosensoric processes. Visually handicapped persons can compensate the visual information deficit through improved peripheral-vestibular and somatosensoric perception and cerebellar processing. In the second part, subjects with normal vision were examined under simulated visual conditions, e.g., hyperopia (3.0 D), reduced visual acuity (VA = 20/200), yoke prisms (4 cm/m) and pursuits (pendulum). Changes in postural parameters due to simulations have been compared to a standard situation (open eyes [NO], fixation distance 3 m). Visual simulations showed influence on frequency range F1. Compared to the standard situation, significant differences have been found in reduced visual acuity, pursuits and yoke prisms. A loss of stability was measured for simulated hyperopia, pendulum and yoke prisms base down. Stability regulation can be understood as a multi-sensoric process by the visual, vestibular, somatosensoric and cerebellar system. Reduced influence of a single subsystem is compensated by the other subsystems. Obviously the main part of reduced visual input is compensated by the vestibular system. Moreover, the body sway, represented by the stability indicator, increased in this situation.

Visual and postural control of an arbitrary posture: The handstand

The aim of this study was to increase our understanding of postural regulation by analysing an arbitrary posture - the handstand. We assessed the relative influence of peripheral vision and central visual anchoring on the postural balance of gymnasts in the inverted-stand posture. Displacements of the centre of pressure, the angles between the body segments, and the gymnast's height in the handstand were analysed. Postural regulation in the handstand appeared to be organized according to a system similar to that in erect posture, with three articular levels suggesting the existence of a typical organization of human posture. Moreover, both intra-modal (central and peripheral vision) and inter-modal sensory systems (vision and other balance systems) contributed to the postural regulation. The results are interpreted in terms of an ecological approach to posture in which postural regulation can be considered as an emergent phenomenon.

Posturographic testing and motor learning predictability in gymnasts

PURPOSE

One aim of this study was to find if there was a difference between balance and stability between elite level gymnasts and non-gymnasts. Another aim was to find if there was a relationship between dynamic posturographic scores associated with sway fatigue or adaptability and the ability to learn new gymnastic routines. The ultimate aim of the study was to improve gymnastic performance while reducing the probability of injury.

METHODS

Computer dynamic posturography (CDP) provided stability scores, fatigability ratios and adaptation ratios in elite level gymnasts and non-gymnasts controls. Relationships between the postural integrity of gymnasts and non-gymnasts were calculated. The gymnasts were trained in a novel gymnastic routine and performance outcomes were compared to the CDP outcomes.

RESULTS

Tests of postural stability have shown that gymnasts have greater postural stability than non-gymnasts. Gymnasts whose adaptability scores were higher were able to learn and perform new motor routines better than those with lower adaptability scores or high fatigability ratios.

CONCLUSIONS

While gymnasts have greater postural integrity than do non-gymnasts, CDP can identify individuals whose ability to perform new motor activities might be impaired. Methodology to improve functional stability not associated with the motor task may contribute to increased sports performance and decreased probability of injury.